WO2020233424A1 - 基于事件函数类型的收据存储方法和节点 - Google Patents

基于事件函数类型的收据存储方法和节点 Download PDF

Info

Publication number
WO2020233424A1
WO2020233424A1 PCT/CN2020/089385 CN2020089385W WO2020233424A1 WO 2020233424 A1 WO2020233424 A1 WO 2020233424A1 CN 2020089385 W CN2020089385 W CN 2020089385W WO 2020233424 A1 WO2020233424 A1 WO 2020233424A1
Authority
WO
WIPO (PCT)
Prior art keywords
event
transaction
receipt
smart contract
log
Prior art date
Application number
PCT/CN2020/089385
Other languages
English (en)
French (fr)
Inventor
刘琦
闫莺
魏长征
Original Assignee
创新先进技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201910419752.4A external-priority patent/CN110264194B/zh
Priority claimed from CN201910420689.6A external-priority patent/CN110276684B/zh
Priority claimed from CN201910419924.8A external-priority patent/CN110247895B/zh
Priority claimed from CN201910420663.1A external-priority patent/CN110245946B/zh
Priority claimed from CN201910419897.4A external-priority patent/CN110278193B/zh
Priority claimed from CN201910419908.9A external-priority patent/CN110223172B/zh
Priority claimed from CN201910419943.0A external-priority patent/CN110245504B/zh
Priority claimed from CN201910419930.3A external-priority patent/CN110263090B/zh
Priority claimed from CN201910419907.4A external-priority patent/CN110263088B/zh
Priority claimed from CN201910419925.2A external-priority patent/CN110263089B/zh
Priority claimed from CN201910419898.9A external-priority patent/CN110263087B/zh
Priority claimed from CN201910419959.1A external-priority patent/CN110264197B/zh
Priority claimed from CN201910419158.5A external-priority patent/CN110263086B/zh
Priority claimed from CN201910420666.5A external-priority patent/CN110263091B/zh
Application filed by 创新先进技术有限公司 filed Critical 创新先进技术有限公司
Publication of WO2020233424A1 publication Critical patent/WO2020233424A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F16/00—Information retrieval; Database structures therefor; File system structures therefor
    • G06F16/20—Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
    • G06F16/27—Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
    • G06F21/60—Protecting data

Definitions

  • One or more embodiments of this specification relate to the field of terminal technology, and in particular to a method and node for storing receipts based on event function types.
  • Blockchain technology is built on a transmission network (such as a peer-to-peer network).
  • the network nodes in the transmission network use chained data structures to verify and store data, and use distributed node consensus algorithms to generate and update data.
  • TEE Trusted Execution Environment
  • TEE can play the role of a black box in the hardware. Neither the code executed in the TEE nor the data operating system layer can be peeped. Only the pre-defined interface in the code can operate on it.
  • plaintext data is calculated in TEE instead of complex cryptographic operations in homomorphic encryption. There is no loss of efficiency in the calculation process. Therefore, the combination with TEE can achieve less performance loss. Under the premise, the security and privacy of the blockchain are greatly improved. At present, the industry is very concerned about TEE solutions.
  • TEE solutions including TPM (Trusted Platform Module) for software and Intel SGX (Software Guard Extensions) for hardware. , Software Protection Extension), ARM Trustzone (trust zone) and AMD PSP (Platform Security Processor, platform security processor).
  • one or more embodiments of this specification provide a receipt storage method and node based on the event function type.
  • a method for storing receipts based on event function types including:
  • the first blockchain node receives the encrypted transaction corresponding to the smart contract
  • the first blockchain node decrypts the transaction in a trusted execution environment to obtain the smart contract, and the smart contract includes a special event function;
  • the first blockchain node executes the smart contract in the trusted execution environment to obtain receipt data, where the receipt data includes a log corresponding to the special event function;
  • the first blockchain node stores the receipt data, so that at least part of the receipt content in the log corresponding to the special event function is stored in plain text, and the rest of the receipt data is stored in cipher text.
  • a receipt storage node based on event function type including:
  • the receiving unit receives the encrypted transaction corresponding to the smart contract
  • a decryption unit decrypting the transaction in a trusted execution environment to obtain the smart contract, the smart contract including a special event function
  • the storage unit stores the receipt data, so that at least a part of the receipt content in the log corresponding to the special event function is stored in plain text, and the rest of the receipt data is stored in cipher text.
  • an electronic device including:
  • a memory for storing processor executable instructions
  • the processor implements the method according to the first aspect by running the executable instruction.
  • a computer-readable storage medium is provided, and computer instructions are stored thereon, which, when executed by a processor, implement the steps of the method described in the first aspect.
  • Fig. 1 is a schematic diagram of creating a smart contract according to an exemplary embodiment.
  • Fig. 2 is a schematic diagram of invoking a smart contract provided by an exemplary embodiment.
  • Fig. 3 is a flowchart of a method for storing receipts based on event function types according to an exemplary embodiment.
  • Fig. 4 is a schematic diagram of implementing privacy protection on blockchain nodes according to an exemplary embodiment.
  • Fig. 5 is a schematic diagram of the functional logic of implementing a blockchain network through a system contract and a chain code provided by an exemplary embodiment.
  • Fig. 6 is a block diagram of a receipt storage node based on an event function type provided by an exemplary embodiment.
  • the steps of the corresponding method may not be executed in the order shown and described in this specification.
  • the method includes more or fewer steps than described in this specification.
  • a single step described in this specification may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this specification may also be combined into a single step in other embodiments. description.
  • Blockchain is generally divided into three types: Public Blockchain, Private Blockchain and Consortium Blockchain.
  • the most decentralized one is the public chain.
  • the public chain is represented by Bitcoin and Ethereum. Participants who join the public chain can read the data records on the chain, participate in transactions, and compete for the accounting rights of new blocks. Moreover, each participant (ie, node) can freely join and exit the network, and perform related operations.
  • the private chain is the opposite.
  • the write permission of the network is controlled by an organization or institution, and the data read permission is regulated by the organization.
  • the private chain can be a weakly centralized system with strict restrictions and few participating nodes. This type of blockchain is more suitable for internal use by specific institutions.
  • the alliance chain is a block chain between the public chain and the private chain, which can achieve "partial decentralization".
  • Each node in the alliance chain usually has a corresponding entity or organization; participants are authorized to join the network and form a stakeholder alliance to jointly maintain the operation of the blockchain.
  • a smart contract on the blockchain is a contract that can be triggered and executed by a transaction on the blockchain system.
  • Smart contracts can be defined in the form of codes.
  • EVM Ethereum Virtual Machine
  • bytecode virtual machine code
  • the EVM of node 1 can execute the transaction and generate a corresponding contract instance.
  • "0x6f8ae93" in the figure 1 represents the address of this contract, the data field of the transaction can be stored in bytecode, and the to field of the transaction is empty.
  • the contract is successfully created and can be called in the subsequent process.
  • a contract account corresponding to the smart contract appears on the blockchain and has a specific address, and the contract code will be stored in the contract account.
  • the behavior of the smart contract is controlled by the contract code.
  • smart contracts enable virtual accounts containing contract codes and account storage (Storage) to be generated on the blockchain.
  • the EVM of a certain node can execute the transaction and generate a corresponding contract instance.
  • the from field of the transaction in Figure 2 is the address of the account of the transaction initiator (ie Bob), the "0x6f8ae93" in the to field represents the address of the called smart contract, and the value field in Ethereum is the value of Ether ,
  • the method and parameters of calling the smart contract are stored in the data field of the transaction. Smart contracts are executed independently on each node in the blockchain network in a prescribed manner. All execution records and data are stored on the blockchain, so when the transaction is completed, the blockchain will be stored on the blockchain that cannot be tampered with. Lost transaction certificate.
  • the receipt data obtained by a node executing a transaction can include the following:
  • the Result field indicates the execution result of the transaction
  • the Gas used field indicates the gas value consumed by the transaction
  • the Logs field indicates the log generated by the transaction.
  • the log can further include the From field, To field, Topic field, and Log data field, among which the From field indicates the account address of the initiator of the call, and the To field indicates the called object (such as a smart contract)
  • the account address and Topic field indicate the subject of the log, and the Log data field indicates the log data;
  • the Output field indicates the output of the transaction.
  • log is a function provided in Ethereum.
  • the logs generated by each event contained in the code can be recorded.
  • the log allows to record the details of the event.
  • the From and To fields mentioned above can indicate the accounts of both parties involved in the transaction, and the Topic field can contain the value of the state variables referenced by the event after the code is executed, etc. Therefore, not only can the log be used as relevant evidence after the transaction is executed on the blockchain, it can also be used to drive related operations.
  • the callback function of JavaScript can be used to monitor events, and the corresponding log can be generated when the event is triggered. Therefore, by retrieving the log content, the DAPP (Decentralized Application) client can be driven to perform related execution when the preset log content is retrieved Processing operations, etc.
  • DAPP Decentralized Application
  • the block chain is a data set stored in a database of a node and organized by a specific logic.
  • the database as described later, may be a storage medium, such as a persistent storage medium, on a physical carrier.
  • Step 302 the first blockchain node receives the encrypted transaction corresponding to the smart contract.
  • the user can directly generate a transaction on the first blockchain node; or, the user can generate a transaction on the client, and send the transaction to the first blockchain node through the client; or, the client
  • the terminal can send the above transaction to the second blockchain node, and the second blockchain node sends the transaction to the first blockchain node.
  • the transaction content may include the account address of the smart contract being called, the methods and parameters that need to be passed in, and so on.
  • Step 304 The first blockchain node decrypts the transaction in a trusted execution environment to obtain the smart contract, and the smart contract includes a special event function.
  • the smart contract may include one or more events, and each event is used to implement predefined related processing logic. After each event contained in the smart contract is called and executed, the corresponding Logs field will be generated. For example, when the smart contract contains event 1 and event 2, event 1 can generate the corresponding Logs field, and event 2 can generate the corresponding Logs field. , So that the receipt data corresponding to the smart contract contains multiple Logs fields at the same time.
  • the events contained in the smart contract can be divided into special event functions and ordinary event functions.
  • the logs generated by the ordinary event functions are stored in cipher text to achieve privacy protection; the special event functions generated Logs need to store at least part of the log fields in plaintext on the premise of meeting the privacy protection requirements, so that the content of this part of the log fields can be retrieved to drive the implementation of related operations.
  • the special event function may be a predefined global event function in the blockchain network.
  • the event function belonging to the "special event function” can be recorded, for example, it can be recorded in the special event function list; accordingly, by combining the event function contained in the smart contract with By comparing the above special event function list, it can be determined whether the event function included in the smart contract is the above special event function.
  • the special event function can be any function defined in the smart contract, and by adding a type identifier for the event function in the smart contract, the event function can be marked as a special event function.
  • the code example of the event function included in the smart contract is as follows:
  • Event buy_candy1 expose(who,candy_num);
  • the smart contract defines 3 events: event buy_candy1, event buy_candy2_1 and event buy_candy2_2.
  • the event buy_candy1 By adding the type identifier "expose" to the event buy_candy1, the event buy_candy1 can be marked as the above special event function; correspondingly, since the event buy_candy2 does not contain the type identifier "expose", the event buy_candy2 is a normal event function Instead of the special event function mentioned above.
  • the event buy_candy2_2 does not add the type identifier "expose”, it contains the content "from”, which corresponds to the From field, which indicates that the From field in the log generated by the event buy_candy2_2 needs to be in plaintext/ciphertext form Therefore, the content "from” not only indicates that the event buy_candy2_2 belongs to a special event function, but also indicates the fields that need plaintext/ciphertext storage (the fields that need plaintext storage are the exposed log fields below, and the fields that need ciphertext storage are the following Encrypted log field).
  • High-level languages supported by Ethereum such as Solidity, Serpent, and LLL languages
  • a smart contract written in a high-level language can be compiled into a corresponding bytecode through a compiler, and the first blockchain node will finally execute the smart contract in the form of bytecode in the EVM virtual machine.
  • the above-mentioned type identifier can be the same in high-level language and bytecode smart contract code, or the first type identifier in high-level language smart contract code, and the second type in bytecode smart contract code Type identifier, the first type identifier and the second type identifier can correspond to each other.
  • the encrypted transaction can be kept in a state of privacy protection, and the transaction content can be prevented from being exposed.
  • the transaction content may contain information such as the account address of the transaction initiator and the account address of the transaction target. Encryption processing can ensure that these transaction contents cannot be directly read.
  • the foregoing transaction may be encrypted by a symmetric encryption algorithm, or may be encrypted by an asymmetric algorithm.
  • the encryption algorithm used by symmetric encryption such as DES algorithm, 3DES algorithm, TDEA algorithm, Blowfish algorithm, RC5 algorithm, IDEA algorithm, etc.
  • Asymmetric encryption algorithms such as RSA, Elgamal, knapsack algorithm, Rabin, D-H, ECC (elliptic curve encryption algorithm), etc.
  • the foregoing transaction may be encrypted by a combination of a symmetric encryption algorithm and an asymmetric encryption algorithm.
  • the client can use a symmetric encryption algorithm to encrypt the transaction content, that is, use the symmetric encryption algorithm key to encrypt the transaction content, and use an asymmetric encryption algorithm to encrypt the symmetric encryption algorithm
  • the key used for example, the key used in the public key encryption symmetric encryption algorithm using an asymmetric encryption algorithm.
  • the first blockchain node After the first blockchain node receives the encrypted transaction, it can first decrypt it with the private key of the asymmetric encryption algorithm to obtain the key of the symmetric encryption algorithm, and then decrypt it with the key of the symmetric encryption algorithm to obtain the transaction content.
  • a transaction When a transaction is used to call a smart contract, it can be a call of multiple nested structures. For example, the transaction directly calls smart contract 1, and the code of smart contract 1 calls smart contract 2, and the code in smart contract 2 points to the contract address of smart contract 3, so that the transaction actually calls the code of smart contract 3 indirectly , And smart contract 3 includes a certain event function. In this way, it is equivalent to the event function included in smart contract 1.
  • the specific implementation process is similar to the above process, and will not be repeated here.
  • Step 306 The first blockchain node executes the smart contract in the trusted execution environment to obtain receipt data, where the receipt data includes a log corresponding to the special event function.
  • the first blockchain node when the first blockchain node executes the code of the smart contract, it will generate the corresponding Logs field for each event function contained in the code, that is, generate a log corresponding to each event function.
  • the log corresponding to the special event function can be further determined, so that at least a part of the log field corresponding to the special event function is stored in plain text.
  • the first blockchain node after receiving a transaction invoking a smart contract from a client, the first blockchain node can check whether the transaction is valid, the format is correct, and the signature of the transaction is legal.
  • the nodes in Ethereum are generally nodes that compete for the right to bookkeeping. Therefore, the first blockchain node as the node that competes for the right to bookkeeping can execute the transaction locally. If one of the nodes competing for the accounting right wins in the current round of the accounting right, it becomes the accounting node. If the first blockchain node wins this round of competition for accounting rights, it becomes the accounting node; of course, if the first blockchain node does not win in this round of competition for accounting rights, it is not Accounting nodes, and other nodes may become accounting nodes.
  • a smart contract is similar to a class in object-oriented programming.
  • the result of execution generates a contract instance corresponding to the smart contract, similar to the object corresponding to the generated class.
  • the process of executing the code used to create a smart contract in a transaction will create a contract account and deploy the contract in the account space.
  • the address of the smart contract account is generated from the sender's address ("0xf5e -- in Figure 1-2) and the transaction nonce (nonce) as input, and is generated by an encryption algorithm, such as in Figure 1-2
  • the contract address "0x6f8ae93" is generated from the sender's address "0xf5e" and the nonce in the transaction through an encryption algorithm.
  • consensus algorithms such as Proof of Work (POW), Proof of Stake (POS), and Delegated Proof of Stake (DPOS) are adopted in blockchain networks that support smart contracts. All nodes competing for the right to account can execute the transaction after receiving the transaction including the creation of a smart contract. One of the nodes competing for the right to bookkeeping may win this round and become the bookkeeping node.
  • the accounting node can package the transaction containing the smart contract with other transactions and generate a new block, and send the generated new block to other nodes for consensus.
  • the nodes with the right to book accounts have been agreed before this round of bookkeeping. Therefore, after the first blockchain node receives the above transaction, if it is not the accounting node of this round, it can send the transaction to the accounting node.
  • accounting nodes which can be the first blockchain node
  • the accounting node packages the transaction (or other transactions together) and generates a new block
  • the generated new block or block header is sent to other nodes for consensus.
  • the accounting nodes in this round can package and package the transaction. Generate a new block, and send the header of the generated new block to other nodes for consensus. If other nodes receive the block and verify that there is no problem, they can append the new block to the end of the original block chain to complete the accounting process and reach a consensus; if the transaction is used to create a smart contract, then The deployment of the smart contract on the blockchain network is completed. If the transaction is used to call the smart contract, the call and execution of the smart contract are completed. In the process of verifying the new block or block header sent by the accounting node, other nodes may also execute the transaction in the block.
  • the execution process can generally be executed by a virtual machine. Taking Ethereum as an example, it supports users to create and/or call some complex logic in the Ethereum network. This is the biggest challenge that distinguishes Ethereum from Bitcoin blockchain technology.
  • the core of Ethereum as a programmable blockchain is the Ethereum Virtual Machine (EVM), and every Ethereum node can run EVM.
  • EVM is a Turing complete virtual machine, which means that various complex logic can be implemented through it. Users publish and call smart contracts in Ethereum run on the EVM.
  • the first blockchain node can execute the decrypted smart contract code in a Trusted Execution Environment (TEE).
  • TEE Trusted Execution Environment
  • the first blockchain node can be divided into a regular execution environment (on the left in the figure) and TEE, and transactions submitted by the client (as described above, transactions can have other sources; here, the client submits Take the transaction as an example to illustrate)
  • First enter the "transaction/query interface" in the regular execution environment for identification.
  • Transactions that do not require privacy processing can be left in the regular execution environment for processing (here can be based on the user type of the transaction initiator , Transaction type, identifier contained in the exchange, etc.
  • TEE is isolated from the conventional execution environment.
  • the transaction is encrypted before entering the TEE, and it is decrypted into the transaction content in the clear in the trusted execution environment, so that the transaction content in the clear text can be efficiently processed in the TEE and in the TEE under the premise of ensuring data security.
  • the receipt data in plaintext is generated in.
  • TEE is a secure extension based on CPU hardware and a trusted execution environment completely isolated from the outside.
  • TEE was first proposed by Global Platform to solve the security isolation of resources on mobile devices, and parallel to the operating system to provide a trusted and secure execution environment for applications.
  • ARM's Trust Zone technology is the first to realize the real commercial TEE technology.
  • security requirements are getting higher and higher.
  • Not only mobile devices, cloud devices, and data centers have put forward more needs for TEE.
  • the concept of TEE has also been rapidly developed and expanded. Compared with the originally proposed concept, TEE is a broader TEE. For example, server chip manufacturers Intel, AMD, etc. have successively introduced hardware-assisted TEE and enriched the concept and characteristics of TEE, which has been widely recognized in the industry.
  • Intel Software Protection Extensions (SGX) and other TEE technologies isolate code execution, remote attestation, secure configuration, secure storage of data, and trusted paths for code execution.
  • the applications running in the TEE are protected by security and are almost impossible to be accessed by third parties.
  • SGX provides an enclave (also called an enclave), which is an encrypted trusted execution area in the memory, and the CPU protects data from being stolen.
  • enclave also called an enclave
  • the CPU protects data from being stolen.
  • a part of the area EPC Enclave Page Cache, enclave page cache or enclave page cache
  • the encryption engine MEE Memory Encryption Engine
  • SGX users can distrust the operating system, VMM (Virtual Machine Monitor), and even BIOS (Basic Input Output System). They only need to trust the CPU to ensure that private data will not leakage.
  • the private data can be encrypted and transmitted to the circle in cipher text, and the corresponding secret key can also be transmitted to the circle through remote certification. Then, the data is used for calculation under the encryption protection of the CPU, and the result will be returned in ciphertext. In this mode, you can use powerful computing power without worrying about data leakage.
  • the transaction contains the code of the smart contract
  • the first blockchain node can decrypt the transaction in the TEE to obtain the code of the smart contract contained therein, and then Execute this code in TEE.
  • the first blockchain node can execute the code in the TEE (if the called smart contract handles the encryption state, the smart contract needs to be executed in the TEE first. Decrypt to get the corresponding code).
  • the first blockchain node may use the newly added processor instructions in the CPU to allocate a part of the area EPC in the memory, and encrypt the above-mentioned plaintext code and store it in the EPC through the encryption engine MEE in the CPU.
  • the encrypted content in EPC is decrypted into plain text after entering the CPU.
  • the plaintext code for executing smart contracts can load the EVM into the enclosure.
  • the key management server can calculate the hash value of the local EVM code and compare it with the hash value of the EVM code loaded in the first blockchain node. The correct comparison result is a necessary condition for passing remote certification. , So as to complete the measurement of the code loaded in the SGX circle of the first blockchain node. After measurement, the correct EVM can execute the above smart contract code in SGX.
  • Step 308 The first blockchain node stores the receipt data so that at least a part of the receipt content in the log corresponding to the special event function is stored in plain text, and the rest of the receipt data is stored in cipher text.
  • the first blockchain node may store the log generated by the special event function completely in plain text, that is, all log fields contained in the log are stored in plain text.
  • the first blockchain node can store the remaining receipt content of the receipt data in ciphertext form.
  • the first blockchain node may determine the exposure log field corresponding to the special event function, and at least a part of the above-mentioned receipt content matches the exposure log field corresponding to the special event function, so that the receipt content corresponding to the log field is exposed Stored in plain text, and the receipt content corresponding to the non-exposed log field in the log of the special event function, and all the receipt content corresponding to the log of the ordinary event function are still stored in cipher text, so that you can ensure that the exposed log field can be implemented At the same time of retrieval operation, privacy protection is achieved as much as possible.
  • the special event function includes a marked exposure log field.
  • the first blockchain node may read the identifier contained in the special event function, and determine one or more log fields marked by the identifier as the above-mentioned exposed log field.
  • the code examples of the special event functions included in the smart contract are as follows:
  • the smart contract defines 2 events: event buy_candy3 and event buy_candy4.
  • the content "from” and “to” can be used as type identifiers to indicate that the events buy_candy3 and event buy_candy4 belong to special event functions, and can also indicate the From field in the generated log.
  • the To field needs to be stored in plain text.
  • the content "from” and “to” are only used to indicate that the From field and the To field need to be stored in plain text, and it is necessary to determine whether the event buy_candy3 and event buy_candy4 are special event functions by other means.
  • the event buy_candy3 and the event buy_candy4 are added with the above-mentioned type identifiers, if these two events are the aforementioned predefined special event functions, such as in the aforementioned special event function list, then the events buy_candy3 and event buy_candy4 can be determined It is a special event function.
  • the event buy_candy3 and the event buy_candy4 can also use the labeling scheme of the aforementioned type identifier, which is not limited here.
  • the event buy_candy3 is a special event function.
  • the "from" contained in the event buy_candy3 is used to indicate the log field From, so that in the log Logs generated corresponding to the event buy_candy3, the From field will be stored in plain text, while the remaining To field, Topic field, and Log data field Stored in cipher text.
  • the event buy_candy4 is a special event function.
  • the "to" contained in the event buy_candy4 is used to indicate the log field to, so that in the log Logs generated corresponding to the event buy_candy4, the To field will be stored in plain text, and the remaining From, Topic, and Log data fields Stored in cipher text.
  • the specified encrypted log field can be included in the special event function, and the exposed log field is the remaining log fields.
  • the code examples of the special event functions included in the smart contract are as follows:
  • the smart contract defines 2 events: event buy_candy5 and event buy_candy6.
  • the content "from” and “to” can be used as type identifiers to indicate that the events buy_candy5 and event buy_candy6 belong to special event functions, and can also indicate the From field in the generated log.
  • the To field needs to be stored in cipher text.
  • the content "from” and “to” are only used to indicate that the From and To fields in the generated log need to be stored in ciphertext, and other methods need to be used to determine whether the event buy_candy5 and event buy_candy6 are special event functions. For example, although both the event buy_candy5 and the event buy_candy6 are added with the above type identifiers, if these two events are the aforementioned predefined special event functions, such as in the aforementioned special event function list, then the events buy_candy5 and event buy_candy6 can be determined It is a special event function.
  • the event buy_candy5 and the event buy_candy6 can also use the labeling scheme of the aforementioned type identifier, which is not limited here.
  • the event buy_candy5 is a special event function.
  • the "from" contained in the event buy_candy5 is used to indicate the log field From, so that in the log Logs generated corresponding to the event buy_candy5, the From field will be stored in cipher text, and the remaining To fields, Topic fields, and Log data Fields, etc. are exposed log fields, which are all stored in plain text.
  • the event buy_candy6 is a special event function.
  • the "to" contained in the event buy_candy6 is used to indicate the log field to, so that in the log Logs generated corresponding to the event buy_candy6, the To field will be stored in ciphertext, and the remaining From field, Topic field, and Log data Fields, etc. are exposed log fields, which are all stored in plain text.
  • Event buy_candy8 show_to(who,candy_num);
  • the smart contract defines 2 events: event buy_candy7 and event buy_candy8.
  • the event buy_candy7 contains the type identifier "expose". According to the above, the event buy_candy7 can be determined as a special event function. Further, the identifier "_from” after the type identifier "expose” is used to indicate the log field From, so that in the log Logs generated corresponding to the event buy_candy7, the From field will be stored in plain text, while the remaining To fields and Topic The fields, Log data fields, etc. are stored in cipher text.
  • the event buy_candy8 does not contain the type identifier "expose"; however, it is possible to identify whether the event buy_candy8 is the aforementioned special event function by other means. For example, if the event buy_candy8 is in the aforementioned special event function list, then it can be determined that the event buy_candy8 is Special event function. Further, the identifier "show_to" contained in the event buy_candy8 is used to indicate the log field to, so that in the log Logs generated corresponding to the event buy_candy8, the To field will be stored in plain text, and the remaining From field, Topic field, and Log data The fields, etc. are stored in cipher text.
  • the special event function can include an identifier for marking encrypted log fields, and the exposed log fields are the remaining log fields.
  • the smart contract defines 2 events: event buy_candy9 and event buy_candy10.
  • the event buy_candy9 contains the type identifier "expose". According to the above, the event buy_candy9 can be determined as a special event function. Further, the identifier "hide_from” after the type identifier "expose” is used to indicate the log field From, so that in the log Logs generated corresponding to the event buy_candy9, the From field will be stored in cipher text, and the remaining To fields, Topic fields, Log data fields, etc. are exposed log fields, which are stored in plain text.
  • the event buy_candy10 does not contain the type identifier "expose”; however, it is possible to identify whether the event buy_candy10 is the aforementioned special event function by other means. For example, when the event buy_candy10 is in the aforementioned special event function list, it can be determined that the event buy_candy10 is special Event function. Further, the identifier "hide_to" in the event buy_candy10 is used to indicate the log field to, so that in the log Logs generated corresponding to the event buy_candy10, the To field will be stored in cipher text, and the remaining From field, Topic field, and Log data Fields, etc. are exposed log fields, which are all stored in plain text.
  • identifiers used to indicate exposed log fields or encrypted log fields.
  • the identifiers are in high-level languages and smart contracts in the form of bytecodes.
  • the codes can be the same, or the smart contract code in the high-level language is the first identifier, and the smart contract code in the bytecode form is the second identifier, and the first identifier and the second identifier can correspond to each other.
  • the mapping relationship between the special event function and the exposed log field can be predefined , Or the mapping relationship between the special event function and the encrypted log field, so that the first blockchain node can obtain the predefined above mapping relationship, and determine the special event function according to the special event function included in the smart contract and the above mapping relationship The corresponding exposure log field.
  • mapping relationship includes "Event buy_candy11-from_to", "Event buy_candy12-topic” and other content
  • the above mapping relationship "Event buy_candy11-from_to” can be queried. It can be determined that the exposure log fields corresponding to the event "Event buy_candy11” are the From field and the To field. If the event "Event buy_candy12" is included in the smart contract, then the above mapping relationship "Event buy_candy12-topic” can be found
  • the exposure log field corresponding to the event "Event buy_candy12" is the Topic field.
  • mapping relationship may be recorded in the system contract. If there is no upgrade requirement for the above mapping relationship, the mapping relationship can also be recorded in the chain code of the blockchain network.
  • the first blockchain node reads the code of the system contract, and the code of the system contract defines the receipt data storage logic related to the special event function; correspondingly, the first blockchain node
  • the code of the system contract is executed to store at least one receipt field in the log corresponding to the special event function in plaintext when the smart contract includes a special event function, and the rest of the receipt data is stored in clear text. Stored in cipher text.
  • the receipt data storage logic related to the special event function may include: recognition logic for the special event function, confirmation logic for the exposed log field, and processing logic for the exposed log field.
  • the identification logic of the special event function is used to instruct the first blockchain node to identify the special event function contained in the smart contract.
  • the system contract can record a predefined list of special event functions, or the system contract can record
  • the type identifier identifies the processing logic of the special event function.
  • the confirmation logic for the exposure log field is used to instruct the first blockchain node to identify the exposure log field corresponding to the special event function.
  • the system contract can record the mapping relationship between the above special event function and the exposure log field, or
  • the system contract may record processing logic for identifying the exposed log field based on the identifier (the identifier used to indicate the exposed log field or the encrypted log field as described above).
  • the processing logic for the exposed log field is used to instruct the first blockchain node to store the content of the receipt corresponding to the exposed log field in plain text, and store the remaining receipt content in cipher text.
  • the computing device By running the program code of the blockchain (hereinafter referred to as the chain code) on the computing device (physical machine or virtual machine), the computing device can be configured as a blockchain node in the blockchain network, such as the first Blockchain nodes, etc.
  • the first blockchain node runs the above chain code to realize the corresponding functional logic. Therefore, when the blockchain network is created, the receipt data storage logic related to the special event function described above can be written into the chain code, so that each blockchain node can implement the receipt data storage logic; Take a blockchain node as an example.
  • the receipt data storage logic is the above:
  • the receipt data storage logic can specifically define the exposed fields corresponding to each transaction type, so that the first blockchain node can, according to the transaction type, Determine which receipt content in the receipt data generated by the transaction needs to be stored in plain text and which receipt content needs to be stored in cipher text.
  • chain code is used to realize the basic functions of the blockchain network, and the function expansion during operation can be achieved through the system Realized by way of contract.
  • the system contract includes code in the form of bytecode, for example, the first blockchain node can run the system contract code (for example, according to the unique corresponding address "0x53a98" to read the system The code in the contract) to realize the functional supplement of the chain code.
  • the system contract read by the first blockchain node may include a preset system contract configured in the genesis block of the blockchain network; and, the administrator in the blockchain network (ie, the above-mentioned management user) may have The update authority of the system contract, so as to update the preset system contract such as the above, the system contract read by the first blockchain node may also include the corresponding updated system contract.
  • the updated system contract can be obtained by the administrator after one update of the preset system contract; or, the updated system contract can be obtained by the administrator after multiple iterations of the preset system contract, such as the preset system contract Update the system contract 1, update the system contract 1 to obtain the system contract 2, update the system contract 2 to obtain the system contract 3.
  • the system contract 1, the system contract 2, and the system contract 3 can all be regarded as the updated system contract, but the first Blockchain nodes usually follow the latest version of the system contract. For example, the first blockchain node will follow the code in system contract 3 instead of the code in system contract 1 or system contract 2.
  • the administrator can also publish system contracts in subsequent blocks and update the published system contracts.
  • system contracts in subsequent blocks and update the published system contracts.
  • a certain degree of restrictions should be imposed on the issuance and update of system contracts through methods such as authority management to ensure that the functional logic of the blockchain network can operate normally and avoid unnecessary losses to any users.
  • the first blockchain node can read the code of the system contract.
  • the code of the system contract defines the receipt data storage logic related to the special event function; then, the first blockchain node can execute the code of the system contract At least part of the receipt content corresponding to the special event function contained in the smart contract (such as the receipt content corresponding to the exposed log field) is stored in plain text, and the rest of the receipt content is stored in cipher text.
  • the first blockchain node encrypts the non-exposed log field in the special event function and the receipt content corresponding to the non-special event function by using a key.
  • the encryption may be symmetric encryption or asymmetric encryption. If the first blockchain node uses symmetric encryption, that is, the symmetric key of the symmetric encryption algorithm is used to encrypt the content of the receipt, the client (or other object holding the key) can use the symmetric key pair of the symmetric encryption algorithm The encrypted receipt content is decrypted.
  • the symmetric key may be provided to the first blockchain node in advance by the client. Then, since only the client (actually the user corresponding to the logged-in account on the client) and the first blockchain node have the symmetric key, only the client can decrypt the corresponding encrypted receipt content, avoiding Irrelevant users and even criminals decrypt the encrypted receipt content.
  • the client when the client initiates a transaction to the first blockchain node, the client can use the initial key of the symmetric encryption algorithm to encrypt the transaction content to obtain the transaction; accordingly, the first blockchain node can obtain
  • the initial key is used to directly or indirectly encrypt the content of the receipt.
  • the initial key can be negotiated in advance by the client and the first blockchain node, or sent by the key management server to the client and the first blockchain node, or sent by the client to the first blockchain node.
  • the client can encrypt the initial key with the public key of the asymmetric encryption algorithm, and then send the encrypted initial key to the first block
  • the chain node, and the first blockchain node decrypts the encrypted initial key through the private key of the asymmetric encryption algorithm to obtain the initial key, which is the digital envelope encryption described above, which will not be repeated here.
  • the first blockchain node may use the aforementioned initial key to encrypt the content of the receipt.
  • Different transactions can use the same initial key, so that all transactions submitted by the same user are encrypted with this initial key, or different transactions can use different initial keys.
  • the client can randomly generate an initial key for each transaction. Key to improve security.
  • the first blockchain node may generate a derived key according to the initial key and the impact factor, and encrypt the content of the receipt through the derived key.
  • the derived key can increase the degree of randomness, thereby increasing the difficulty of being compromised and helping to optimize the security protection of data.
  • the impact factor can be related to the transaction; for example, the impact factor can include the specified bits of the transaction hash value.
  • the first blockchain node can associate the initial key with the first 16 bits (or the first 32 bits and the last 16 bits) of the transaction hash value. Bits, last 32 bits, or other bits) are spliced, and the spliced string is hashed to generate a derived key.
  • the first blockchain node may also use an asymmetric encryption method, that is, use the public key of the asymmetric encryption algorithm to encrypt the content of the receipt, and accordingly, the client may use the private key of the asymmetric encryption algorithm.
  • the key decrypts the encrypted receipt content.
  • the key of an asymmetric encryption algorithm for example, can be that the client generates a pair of public and private keys, and sends the public key to the first blockchain node in advance, so that the first blockchain node can use the receipt content Public key encryption.
  • the first blockchain node realizes the function by running the code used to realize the function. Therefore, for the functions that need to be implemented in the TEE, the relevant code also needs to be executed. For the code executed in the TEE, it needs to comply with the relevant specifications and requirements of the TEE; accordingly, for the code used to implement a certain function in the related technology, the code needs to be rewritten in combination with the specifications and requirements of the TEE. Large amount of development, and easy to produce loopholes (bugs) in the process of rewriting, affecting the reliability and stability of function implementation.
  • the first blockchain node can execute the storage function code outside the TEE to store the receipt data generated in the TEE (including the receipt content in plain text that needs to be stored in plain text, and the receipt content in cipher text that needs to be stored in cipher text.
  • TEE Is stored in an external storage space outside the TEE, so that the storage function code can be the code used to implement the storage function in the related technology, and does not need to be rewritten in conjunction with the specifications and requirements of the TEE to achieve safe and reliable receipt data
  • the storage of TEE can not only reduce the amount of related code development without affecting security and reliability, but also reduce TCB (Trusted Computing Base) by reducing the related code of TEE, making TEE technology and regional In the process of combining block chain technology, the additional security risks caused are in a controllable range.
  • TCB Trusted Computing Base
  • the first blockchain node may execute the write cache function code in the TEE to store the above-mentioned receipt data in the write cache in the TEE.
  • the write cache may correspond to the one shown in FIG. 1 "Cache".
  • the first blockchain node outputs the data in the write cache from the trusted execution environment to be stored in the external storage space.
  • the write cache function code can be stored in the TEE in plain text, and the cache function code in the plain text can be directly executed in the TEE; or, the write cache function code can be stored outside the TEE in cipher text, such as the above External storage space (such as the "package + storage” shown in Figure 4, where "package” means that the first blockchain node packages the transaction into blocks outside of the trusted execution environment), the cipher text form
  • the write cache function code is read into the TEE, decrypted into the plaintext code in the TEE, and the plaintext code is executed.
  • Write cache refers to a "buffer" mechanism provided to avoid “impact” to the external storage space when data is written to the external storage space.
  • the above-mentioned write cache can be implemented by using buffer; of course, the write cache can also be implemented by using cache, which is not limited in this specification.
  • the write cache mechanism can be used to write the data in the cache to the external storage space in batches, thereby reducing the gap between the TEE and the external storage space. The number of interactions increases the efficiency of data storage.
  • TEE may need to retrieve the generated data.
  • the data to be called happens to be in the write cache, the data can be read directly from the write cache.
  • the interaction between the external storage space eliminates the decryption process of the data read from the external storage space, thereby improving the data processing efficiency in the TEE.
  • the write cache can also be established outside the TEE.
  • the first blockchain node can execute the write cache function code outside the TEE, so as to store the above receipt data in the write cache outside the TEE, and further write The data in the cache is stored in an external storage space.
  • this specification can further identify the exposed identifier contained in the code of the smart contract corresponding to the transaction, so as to determine at the same time according to the special event function contained in the smart contract and the object indicated by the exposed identifier How to store receipt data. Therefore, the above step 308 can be improved as: the first blockchain node stores the receipt data, so that at least part of the receipt content in the log corresponding to the special event function is stored in plain text, and the rest of the receipt data It is stored in a ciphertext form, and the content of the at least a part of the receipt matches the object indicated by the exposure identifier.
  • the exposed identifier is a global identifier defined in the programming language of the smart contract and is applicable to all smart contracts written in this programming language. Therefore, by defining the exposure identifier in a programming language, so that the code of any smart contract uses the exposure identifier, the storage control of the receipt data can be realized. For example, when a user writes the code of a smart contract, he can mark one or more objects by adding an exposure identifier to the code to indicate that the user wants the receipt content corresponding to this part of the object in the receipt data to be stored in plain text, and the remaining The content of the receipt corresponding to the object marked with the exposed identifier is not allowed to be stored in plain text, and must be stored in cipher text to achieve corresponding privacy protection.
  • the corresponding receipt content is allowed to be stored in plain text; however, this specification can further consider the event function contained in the smart contract and start from the programming language Comprehensive consideration is achieved in the dimensions of the event function and whether to store the content of the receipt corresponding to the object marked by the exposure identifier in plain text.
  • the information related to the event function will be described below, and will not be repeated here.
  • the data field can store the bytecode of the smart contract.
  • the bytecode consists of a series of bytes, and each byte can identify an operation. Based on many considerations such as development efficiency and readability, developers can choose a high-level language to write smart contract code instead of directly writing bytecode.
  • the code of a smart contract written in a high-level language is compiled by a compiler to generate bytecode, and then the bytecode can be deployed on the blockchain.
  • Solidity language As an example, the contract written in it is very similar to the class in the object-oriented programming language. A variety of members can be declared in a contract, including state variables, functions, function modifiers, and events. The following is a simple smart contract code example 1 written in Solidity language:
  • one or more objects can be marked by exposing the identifier, so that the receipt content corresponding to this part of the object in the receipt data is allowed to be stored in plain text (the need to further combine the event function The dimensions are used to determine whether plaintext storage is actually used, and the rest of the receipt content should be stored in ciphertext.
  • one or more objects can also be marked by exposing identifiers to realize the plaintext storage of the relevant receipt content.
  • the exposure identifier may be a receipt field dedicated to indicating that plain text storage is allowed.
  • the keyword plain may be used to characterize the exposure identifier. Then, for the receipt content that you want to store in plain text, you can add plain before the corresponding object (or, you can also associate with the corresponding object in other ways).
  • the object marked by the exposure identifier can include receipt fields, such as the Result field, Gas used field, Logs field, Output field, etc., as described above, or the From field, To field, Topic field, and Log data field further contained in the Logs field Wait.
  • receipt fields such as the Result field, Gas used field, Logs field, Output field, etc., as described above, or the From field, To field, Topic field, and Log data field further contained in the Logs field Wait.
  • the code sample 1 above can be adjusted to the following code sample 2:
  • the fields that need to be stored in plaintext can also be specified.
  • the code of the smart contract can be executed, and the receipt content corresponding to the From field in the generated receipt data is allowed to be stored in plain text. Then the subsequent can be directed to the From field
  • the content of the receipt can be retrieved, for example, the transaction volume initiated by a certain account can be counted.
  • the exposed identifier can also be used to identify other objects.
  • the object identified by the exposure identifier may include state variables. Taking the state variable "price" as an example, the above code example 1 can be adjusted to the following code example 3:
  • the smart contract corresponding to the transaction received by the first blockchain node may be a smart contract written in a high-level language, or may be a smart contract in the form of bytecode.
  • the first blockchain node when the smart contract is a smart contract written in a high-level language, the first blockchain node also compiles the smart contract written in the high-level language through a compiler to generate a smart contract in the form of bytecode to be used in a trusted execution environment In execution.
  • the smart contract in bytecode form can be obtained by compiling the smart contract written in high-level language by the client through the compiler , And the smart contract written in this high-level language is written by the user on the client.
  • the smart contract corresponding to the transaction received by the first blockchain node may be a smart contract generated by the user on the first blockchain node.
  • the first blockchain node also uses a compiler to compile the smart contract written in the high-level language into a smart contract in the form of bytecode; or, the user may also be in the first area Smart contracts in bytecode form are directly written on the blockchain nodes.
  • the smart contract corresponding to the transaction received by the first blockchain node may be a smart contract generated by the user on the client.
  • the client submits the transaction to the first blockchain node.
  • the first blockchain node includes a transaction/query interface, which can be connected with the client, so that the client can submit the above-mentioned transaction to the first blockchain node.
  • the user can use a high-level language to write a smart contract on the client, and then the client uses a compiler to compile the smart contract in the high-level language to obtain the corresponding smart contract in bytecode form.
  • the client can directly send a smart contract written in a high-level language to the first blockchain node, so that the first blockchain node is compiled into a bytecode smart contract by a compiler.
  • the smart contract corresponding to the transaction received by the first blockchain node can be the smart contract in the transaction sent by the client through the second blockchain node.
  • the smart contract is usually in the form of bytecode; of course, the smart contract It can also be a smart contract written in a high-level language, and the first blockchain node can be compiled into a bytecode smart contract by a compiler.
  • the smart contract written in a high-level language and the smart contract in the form of bytecode may have the same exposure identifier.
  • the bytecode can use an exposed identifier different from a high-level language.
  • the code of a smart contract written in a high-level language contains the first identifier and the code of the smart contract in the form of bytecode. If the second identifier is included, there is a corresponding relationship between the first identifier and the second identifier to ensure that after being compiled into bytecode by a high-level language, the function of exposing the identifier will not be affected.
  • the exposed identifier can indicate one or more objects, and these objects have corresponding receipt content in the receipt data.
  • the receipt data contains a log corresponding to the special event function, which is actually part of the receipt content in the receipt data.
  • the cross content of the above two parts of the receipt content can be filtered out, and the cross content can be stored in plain text, and the rest of the receipt data is stored in cipher text.
  • the definition of special event functions is not necessarily based on programming languages. For example, when recording special event functions based on a list of special event functions, even if an event function included in the smart contract originally belongs to a special event function, it can be To change the event function list, update the original special event function to a normal event function, so as to avoid storing the log generated by the event function in plain text, or update the original normal event function to a special event function to make the At least part of the content in the log generated by the event function is stored in plain text.
  • the state variable "price" marked by the exposure identifier "plain” is also a contract-level object, so that when the first blockchain node stores the receipt data, all of the receipt data corresponds to The content of the receipt of the contract-level object "price" is allowed to be stored in clear text.
  • a smart contract can include the following code example 4:
  • the exposed identifier "plain" is located at the forefront of the smart contract code, so that all fields in the receipt data are marked as contract-level objects; at the same time, in the smart contract Contains the event currentPrice1 and event currentPrice2: assuming that the event currentPrice1 corresponds to the special event function defined in the special event function list, and the event currentPrice2 corresponds to the ordinary event function, then in the logs Log1 and Log2 generated by the event currentPrice1 and event currentPrice2, log Log1 All fields included are stored in plain text, and all fields included in log Log2 are stored in cipher text.
  • the From field is the contract-level object mentioned above, so that when the event currentPrice1 is a special event function and the event currentPrice2 is a normal event function, the From field in the log Log1 is Stored in plain text, the rest of the fields are stored in cipher text, and all fields contained in log Log2 are stored in cipher text; and, when the event currentPrice2 is updated as a special event function, then the From field in log Log2 is stored in plain text, and the rest The fields are stored in cipher text.
  • the aforementioned type identifier can be used to indicate whether the event function contained in the smart contract is a special event function.
  • the above code sample 4 can be adjusted to the following code sample 5:
  • the contract-level object includes all the fields in the receipt data; at the same time, the smart contract contains the event currentPrice1 and the event currentPrice2: because the event currentPrice1 contains the above-mentioned
  • the type identifier expose causes the event currentPrice1 to be marked as corresponding to the special event function, while the event currentPrice2 does not contain the type identifier expose, so that the event currentPrice2 is marked as corresponding to the normal event function, then the event currentPrice1 and event currentPrice2 are generated respectively In the logs Log1 and Log2, all fields contained in log Log1 are stored in plain text, and all fields contained in log Log2 are stored in cipher text.
  • the type identifier and the exposed identifier are similar, they are both global identifiers defined in the programming language of the smart contract, but the exposed identifier acts on contract-level objects and the type identifier acts on the event function.
  • the number of event functions included in the event function is large, and the number of objects (such as fields or state variables) involved in the event function is large, there is no need to implement setting operations for each object involved in each event function, which can simplify the code logic , Prevent mislabeling or missing labels.
  • the contract-level object in the above embodiment includes fields, such as the From field. Contract-level objects can also include state variables; for example, the above code example 4 can be adjusted to the following code example 6:
  • the event currentPrice1 and event currentPrice2 refer to the state variable price
  • the event currentPrice3 refers to the state variable price1
  • the type of the state variable price is added before the type int of the state variable "plain"
  • the state variable can be used Price is the contract-level object mentioned above.
  • the event function that references the contract-level object in the log generated by the special event function, the content of the receipt corresponding to the contract-level object is stored in plain text, while the ordinary event function even refers to the contract-level object. The logs are still stored in cipher text.
  • the event currentPrice1 corresponds to the special event function, because the event currentPrice1 references the state variable price as a contract-level object, in the log Logs generated by the event currentPrice1,
  • the contents of receipts related to the state variable price are stored in plain text
  • the event currentPrice2 corresponds to a normal event function, although the event currentPrice2 references the state variable price as a contract-level object, in the log Logs generated by the event currentPrice2
  • the contents of receipts related to the state variable price are stored in ciphertext
  • the event currentPrice3 corresponds to a special event function, since the event currentPrice3 does not reference the state variable price as a contract-level object, the log Logs generated by the event currentPrice3 are all in Stored in ciphertext form.
  • the type of the event function can be marked by the type identifier.
  • the above code sample 6 can be adjusted to the following code sample 7:
  • the state variable price can be marked as a contract-level object by exposing the identifier, while the state variable price1 is not a contract-level object; the events currentPrice1 and currentPrice3 marked by the type identifier expose correspond to special event functions , And the event currentPrice2 corresponds to the normal event function. Therefore, in the log Logs generated by the event currentPrice1, the receipt content related to the state variable price is stored in plain text; in the log Logs generated by the event currentPrice2, the receipt content related to the state variable price is all stored in cipher text Stored; all logs generated by the event currentPrice3 are stored in cipher text.
  • the objects indicated by the exposed identifiers may include: event-level objects corresponding to at least one event defined in the smart contract, so that the first blockchain node generates the special event function when storing the receipt data
  • the part of the receipt content corresponding to the event-level object is stored in plain text.
  • the above event-level object can be set for at least some of the events, so that the part of the receipt content generated by these events that corresponds to the event-level object is stored in plain text, and this The contents of other receipts generated by some events and all the contents of receipts generated by other events are stored in ciphertext.
  • the event currentPrice1 does not add the exposed identifier "plain", it contains the content "from”, which corresponds to the From field, and is used to indicate the From field in the log generated by the event currentPrice1 It needs to be stored in plain text, so the content "from” not only belongs to the above exposed identifier, but also indicates the From field that needs to be stored in plain text. Moreover, since the content "from" is located in the event currentPrice1, the From field is an event-level object, so that when the event currentPrice1 corresponds to a special event function, in the log Logs generated corresponding to the event currentPrice1, the From field will be in plain text. Storage, other fields are stored in cipher text.
  • the generated log Logs are in the form of ciphertext storage.
  • From field is set as an event-level object; for the case where the event-level object is a field type, the specific field may not be specified.
  • code sample 5 can be adjusted to the following code sample 9:
  • Event-level objects can also include state variables. From the perspective of the state variables, the above code example 9 can be interpreted as: the event currentPrice1 refers to the state variables price and price1, and the event currentPrice2 refers to the state variable price1; because by adding the exposure identifier "plain" before the event currentPrice1, you can The state variables price and price1 referenced by the event currentPrice1 are used as the above event-level objects, so that when the event currentPrice1 corresponds to a special event function, in the log Logs generated by the event currentPrice1, the receipts related to the state variables price and price1 The content is stored in plain text.
  • the event-level object when the event-level object includes state variables, it can also specifically indicate one or more state variables referenced by the event.
  • the above code sample 5 can be adjusted to the following code sample 10:
  • the event function corresponding to the event currentPrice1 contains the exposed identifier plain added before the type int of the state variable price, so that the state variable price is configured as an event-level object, and the event-level object is only Applies to the event currentPrice1. Since the exposure identifier plain is located in the event function corresponding to the event currentPrice1, and the event function corresponding to the event currentPrice2 refers to the state variable price but does not label the exposure identifier plain, the event function corresponding to the event currentPrice2 has nothing to do with event-level objects.
  • the event currentPrice1 and the event currentPrice2 correspond to special event functions, only in the log generated by the event currentPrice1, the content of the receipt corresponding to the state variable price as the event-level object is stored in plain text, while the logs generated by the event currentPrice2 are all Stored in cipher text.
  • the event currentPrice1 references the state variable price1, because the state variable price1 is not marked by the exposed identifier, the state variable price1 does not belong to the event-level object, even if the event currentPrice1 corresponds to a special event function, In the log generated by the event currentPrice1, the content of the receipt corresponding to the state variable price1 is still stored in ciphertext.
  • This manual exposes the content of the receipt to a certain extent to realize the driver of the DAPP client or other function extensions.
  • this manual comprehensively considers the object indicated by the exposure identifier and the log generated by the special event function, and can accurately select the receipt content for plaintext storage, that is, it meets both "matching the object indicated by the exposure identifier" and "belonging to a special event"
  • the content of the receipt of the log generated by the function so as to meet the above-mentioned function expansion requirements while ensuring that most of the user’s privacy can be protected.
  • the first blockchain node recognizes the special event function based on the information recorded on the blockchain network (such as the list of special event functions), it can perform the "special event function" after the smart contract has been created. Update to adjust the storage method of receipt data, such as changing the original receipt content stored in plain text to cipher text storage, or changing the original receipt content stored in cipher text to plain text storage.
  • this specification can further identify the user type of the transaction initiator, so as to determine the storage method of the receipt data according to the special event function contained in the smart contract and the user type of the transaction initiator. Therefore, the above step 308 can be improved to: the first blockchain node stores the receipt data, and when the transaction initiator belongs to the preset user type, at least one log field in the log corresponding to the special event function is written in plain text Form storage, the remaining content of the receipt data is stored in cipher text, and when the transaction initiator does not belong to the preset user type, the receipt data is stored in cipher text.
  • the user has a corresponding external account on the blockchain, and initiates transactions or performs other operations on the blockchain based on the external account. For example, when a user initiates a transaction on the blockchain, the transaction is actually initiated through the user’s corresponding external account, so the transaction initiator corresponding to the transaction can be considered the user or the user The corresponding external account.
  • each user type has corresponding privacy protection requirements.
  • Users can be divided into corresponding multiple types according to the differences in privacy protection requirements; or, first, multiple user types are formed according to a certain factor, and then the corresponding privacy protection requirements are configured for each user type.
  • a corresponding relationship can be established between user types and privacy protection requirements, so that the first blockchain node can determine whether it is necessary to implement plaintext storage for logs corresponding to special event functions based on the user type of the transaction initiator.
  • the user type to which the transaction initiator belongs that is, the user type to which the corresponding external account belongs. Therefore, the first blockchain node can determine the external account corresponding to the transaction initiator, and query the user type corresponding to the external account recorded on the blockchain as the user type to which the transaction initiator belongs.
  • the user types corresponding to external accounts can be recorded on the blockchain in various forms:
  • the external account may include a user type field (such as a UserType field) recorded on the blockchain, and the value of the user type field corresponds to the user type.
  • a user type field such as a UserType field
  • the value of the user type field corresponds to the user type. For example, when the value of the user type field is 00, the user type is ordinary user, when the value of the user type field is 01, the user type is advanced user, and when the value of the user type field is 11, the user type is Manage users, etc. Therefore, the first blockchain node can determine the corresponding user type based on the value by reading the user type field of the external account mentioned above.
  • the user type when creating the aforementioned external account, the user type may be configured to be associated with the external account, and the association relationship between the user type and the external account may be recorded in the blockchain, for example, the association relationship may include the user Type and account address of external account.
  • the data structure of the external account does not need to be changed, that is, the external account does not need to include the aforementioned user type field. Therefore, the first blockchain node can determine the user type corresponding to the external account by reading the association relationship recorded on the blockchain and based on the external account corresponding to the transaction initiator.
  • the relationship between the user type and the external account can be recorded in the system contract or chain code, especially when the external account is a preset account of the blockchain network, in the process of creating the system contract or writing the chain code , You can learn about the external account and add the corresponding relationship to the system contract or chain code; or, when the external account is not a preset account, you can update the system contract or chain code when the external account is subsequently created , Add the association relationship corresponding to the external account to the system contract or chain code.
  • the user type of the external account can be modified under certain conditions.
  • the management user may have a modification right item, so that the first blockchain node can change the user type corresponding to the above-mentioned external account according to the change request initiated by the management user.
  • the management user can correspond to the external account preset in the genesis block with management authority, so that the management user can make type changes to other ordinary users, advanced users, etc., such as changing ordinary users to advanced users, and changing advanced users For ordinary users, etc.
  • the logs corresponding to special event functions can be relatively more.
  • Use plaintext storage to retrieve the contents of the receipt stored in plaintext and trigger relatively more types of associated operations.
  • the privacy protection requirements of advanced users are relatively higher, and the requirements for triggering operations based on receipt data are relatively lower.
  • the first blockchain node when the transaction initiator user belongs to the preset user type, the first blockchain node can store the log generated by the special event function in plain text, that is, all log fields contained in the log are stored in plain text. Correspondingly, the first blockchain node can store the remaining receipt content of the receipt data in ciphertext form. And, when the transaction initiator user belongs to the preset user type, the first blockchain node can determine the exposed log field corresponding to the special event function, and store the exposed log field in plain text, and the remaining non-exposed log fields are still It is stored in cipher text, so that privacy protection can be achieved as much as possible while ensuring that retrieval operations can be performed on the exposed log fields.
  • this specification can further identify the exposed fields corresponding to the transaction type, so as to determine the storage method of the receipt data according to the special event functions contained in the smart contract and the exposed fields corresponding to the transaction type at the same time. Therefore, the above step 308 can be improved as: the first blockchain node stores the receipt data, so that the exposed fields in the log corresponding to the special event function are stored in plain text, and the rest of the receipt data is stored in encrypted form. Document storage.
  • the transaction may include a transaction type field (such as a TransType field), and the value of the transaction type field is used to indicate the corresponding transaction type. Therefore, by reading the value of the transaction type field in the exchange, the transaction type can be determined, such as the type of deposit certificate, the type of asset transfer (such as transfer), the type of contract creation, and the type of contract invocation. This manual does not limit this .
  • different types of transactions may respectively have corresponding exposed fields.
  • the exposed field is one or more fields specified in the receipt data.
  • the receipt data needs to be stored in cipher text to protect privacy, it can be combined with the special event function contained in the smart contract to selectively add the special event function to the log
  • the exposed fields of is stored in plaintext, so that subsequent operations such as retrieval can be performed on the contents of the receipt stored in plaintext.
  • the mapping relationship between each transaction type and the exposed field may be predefined, and the mapping relationship may be recorded in the blockchain, so that the first blockchain node can obtain the predefined mapping relationship, And further determine the exposed fields in the receipt data according to the transaction type of the above-mentioned transaction and the mapping relationship.
  • the exposed field corresponding to the attestation type may include all fields except the above-mentioned From field
  • the exposed field corresponding to the asset transfer type may include the above-mentioned To field
  • the exposed field corresponding to the contract creation type and contract invocation type may include the above-mentioned From field. All the fields except for the other transaction types will not be repeated here.
  • mapping relationship can be specifically recorded in the system contract.
  • the mapping relationship can also be recorded in the chain code of the blockchain network.
  • the exposed fields that can be stored in plaintext can be determined according to the differentiated needs of different types of transactions for privacy protection, and further based on the events contained in the smart contract called by the transaction Function, which reflects the differentiated requirements of different types of event functions for privacy protection in the storage process, and has high flexibility.
  • the exposed fields involved in the special event function are stored in plain text, while the non-exposed fields involved in the special event function and all receipt fields involved in the normal event function are stored in cipher text.
  • this specification can further identify the receipt content in the receipt data that meets the preset conditions, so as to determine at the same time according to the special event function contained in the smart contract and the satisfaction of the preset conditions by the receipt content How to store receipt data. Therefore, the above step 308 can be improved as: the first blockchain node stores the receipt data, so that at least one log field in the log corresponding to the special event function that meets the preset condition is stored in plain text, and the receipt The rest of the data is stored in cipher text.
  • all log fields of the log can be compared with corresponding preset conditions, and all log fields that meet the preset conditions are stored in plain text .
  • log fields corresponding to special event functions but satisfying preset conditions, logs corresponding to ordinary event functions, and other receipt contents in receipt data are all stored in cipher text.
  • the exposure log field corresponding to the special event function can be determined, and the exposure log field can be compared with the corresponding preset conditions, so as to satisfy the preset
  • the exposure log field of the condition is stored in clear text.
  • Exposure log fields often involve relatively little privacy content, or do not involve core privacy content, and the risk of storing in plaintext is relatively low; non-exposed log fields may involve relatively more or relatively more important privacy content. Storing in cipher text can ensure that it does not deviate from the core purpose of privacy protection. By judging in combination with preset conditions, it is possible to further filter out the private content that may be contained in the exposed log fields that are not suitable for disclosure, so as to ensure that the retrieval operation can be completed while achieving privacy protection as much as possible.
  • the smart contract under the premise of protecting user privacy, by identifying the event functions contained in the smart contract, it is possible to determine the exposed log fields that can be stored in plain text according to the differentiated requirements of different types of event functions for privacy protection , And further according to the satisfaction of the preset conditions by the exposure log field, the corresponding differentiated requirements are reflected in the storage process, and it has high flexibility.
  • the exposure log fields that meet the preset conditions can be stored in plaintext, and the exposure log fields that do not meet the preset conditions or other receipt content can be stored It must be stored in ciphertext.
  • the content of the preset condition may include at least one of the following: the corresponding log field contains the preset content, the value of the corresponding log field belongs to the preset numerical interval, and so on.
  • the preset content may include: one or more specified keywords, for example, the keyword may include predefined state variables, predefined intermediate variables, etc., so that when a certain exposed log field contains a state variable or intermediate as a keyword Variable, it can be determined that the exposure log field meets the preset conditions.
  • the keyword may include predefined state variables, predefined intermediate variables, etc., so that when a certain exposed log field contains a state variable or intermediate as a keyword Variable, it can be determined that the exposure log field meets the preset conditions.
  • the preset content may include: preset values.
  • the preset value can be a numeric value, which can be compared with the value of a state variable, etc., to determine whether the value of the state variable meets expectations; for another example, the preset value can be composed of numeric values, letters, special symbols, etc.
  • a character string which can be compared with the account address of the transaction initiator, the account address of the transaction target, the log subject, etc. to identify a specific transaction initiator, a specific transaction target, or a specific log subject, etc.
  • the user can store the To field in plain text when the user initiates a transaction against the account address and the exposure log field corresponding to the transaction type includes the To field. , And when a transaction is initiated against another account address, the To field is not allowed to be stored in plain text to avoid leaking privacy.
  • the preset value range can indicate the privacy protection requirements of the relevant receipt fields.
  • the preset value range can be a value range with a smaller value and a lower privacy protection requirement, so that even if the relevant receipt field is disclosed, it will not cause Serious user privacy leakage, but it can be used to automatically trigger related operations such as DAPP client, so as to achieve a certain balance between privacy protection and convenience. Therefore, when the value of the exposure log field is within the preset numerical range, the exposure log field can be stored in plain text.
  • the preset conditions may include general conditions corresponding to all log fields, that is, in the log corresponding to the special event function in the receipt data, all log fields contained in the log have a unified preset condition, so that the All exposure log fields contained in the log need to be compared with this unified preset condition.
  • the preset condition is "contains preset keywords”
  • all the exposure log fields in the log corresponding to the special event function can be compared with the keywords contained in the preset condition to determine that the keyword is included
  • the exposure log field of is used as the exposure log field that meets the above preset conditions.
  • the preset condition may include a dedicated condition corresponding to each log field, that is, in the log corresponding to the special event function in the receipt data, each log field contained in the log has a corresponding preset condition. , So that each exposure log field contained in the log is used for comparison with the corresponding preset conditions.
  • the preset conditions corresponding to different log fields are independent of each other, but may be the same or different.
  • the preset condition corresponding to the From field and the To field may be "whether the preset content is included", and the preset content may be a preset account address, indicating a transaction initiated by or directed to the account address.
  • the preset condition corresponding to the Topic field can be "whether it belongs to the preset value range", and the value of the state variable referenced by the related event can be recorded in the Topic field.
  • it can include a value representing "transfer amount” State variable, indicating that when the transfer amount is in the preset value range (usually the small value range corresponding to a smaller amount), the transfer amount is allowed to be stored in plain text (it can be in plain text when the Topic field is an exposure log field) storage).
  • the preset conditions may be located in the transaction, so that the preset conditions adopted by different exchanges may be different to meet the differences in demand faced by different exchanges; of course, different transactions may also use the same preset conditions.
  • the difference in the preset conditions may be expressed as a difference in at least one dimension in the content of the preset conditions, the receipt fields to which the preset conditions apply, and the processing logic for determining whether the exposure log field meets the preset conditions.
  • the preset condition may be located in the smart contract called by the transaction, or the preset condition may be located in another smart contract called by the smart contract called by the transaction, so that the transaction can be selected by selecting the called smart contract to Determine whether to use the corresponding preset conditions.
  • the smart contract can be pre-created by the transaction initiator or any other user; of course, if the smart contract has a corresponding calling condition, then the above-mentioned transaction can call the smart contract only when the calling condition is met.
  • the calling condition may include : The transaction initiator belongs to the preset whitelist, the transaction initiator does not belong to the preset blacklist or other conditions.
  • the preset condition may be located in the system contract or chain code, so that the preset condition is a global condition applicable to all transactions on the blockchain, and is different from the foregoing transaction or the preset contained in the smart contract.
  • Set conditions so that even if the smart contract called by the transaction or transaction does not contain preset conditions, the storage of log fields can be determined based on the preset conditions defined in the system contract or chain code, and combined with the user type of the transaction initiator the way.
  • the two can contain preset conditions of different dimensions, such as preset conditions.
  • the applicable log fields are different; or, when there is a conflict between the preset conditions contained in the two, the preset conditions contained in the transaction or smart contract may be used by default, or the preset conditions contained in the chain code or system contract may be preferred.
  • Set conditions which depend on the predefined selection logic.
  • this specification can further identify the exposure identifier contained in the code of the smart contract corresponding to the transaction and the user type of the transaction initiator, so as to simultaneously expose according to the special event function contained in the smart contract.
  • the object indicated by the identifier and the user type of the transaction initiator determine the storage method of the receipt data.
  • the above step 308 can be improved as: the first blockchain node stores the receipt data so that when the transaction initiator belongs to the preset user type, at least part of the receipt content in the log corresponding to the special event function
  • the remaining content of the receipt data is stored in a plaintext form, and the remaining content of the receipt data is stored in a ciphertext form, and the at least a part of the receipt content matches the object indicated by the exposure identifier.
  • the smart contract code by adding the exposed identifier plain at the front of the smart contract code, after the smart contract code is executed, all fields in the generated receipt data are allowed to be stored in plain text. Specifically, when the transaction initiator belongs to the preset user type, for the log generated by the special event function in the receipt data, all the contents of the receipt corresponding to the log are allowed to be stored in plain text.
  • the fields that need to be stored in plaintext can also be specified. For example, when the From field is marked by the exposed identifier, the code of the smart contract can be executed.
  • the log generated by the special event function in the receipt data allows the From field to correspond
  • the content of the receipt is stored in plain text, then the subsequent retrieval operation can be performed on the content of the receipt in the From field, for example, the transaction volume initiated by a certain account can be counted.
  • the smart contract code After being executed, when the transaction initiator belongs to the preset user type, for the log generated by the special event function in the receipt data, the receipt content related to the state variable "price” is allowed to be stored in clear text (provided that the transaction initiator belongs to Preset user type), then the subsequent retrieval operation can be performed on the receipt content related to the state variable "price".
  • this specification can further identify the exposed identifier contained in the code of the smart contract corresponding to the transaction and the exposed field corresponding to the transaction type, so as to simultaneously expose according to the special event function contained in the smart contract.
  • the object indicated by the identifier and the exposed field corresponding to the transaction type determine the storage method of the receipt data. Therefore, the above step 308 can be improved as: the first blockchain node stores the receipt data, so that at least part of the receipt content in the log corresponding to the special event function is stored in plain text, and the rest of the receipt data It is stored in a ciphertext form, and the at least a part of the receipt content includes an exposed field indicated by the exposure identifier.
  • the exposed identifier plain is added to the front of the code of the smart contract. From the perspective of the programming language, the exposed identifier plain indicates that the code of the smart contract is executed. All fields in the receipt data are allowed to be stored in plain text, so subsequent retrieval operations can be performed on the receipt content in these fields. For example, for the From field, it can be used to count the transaction volume initiated by an account. By further combining dimensions such as transaction types and event functions, there may be differences in storage solutions for receipt data.
  • the exposed identifier can indicate one or more fields, and these fields have corresponding receipt content in the receipt data. Different types of transactions often have different privacy protection requirements, and the corresponding exposed fields can be allowed to be stored in plain text.
  • the receipt data contains the log corresponding to the special event function, which is actually part of the receipt content in the receipt data.
  • the cross content of the above three parts of receipt content can be filtered out, and the cross content can be stored in plain text. The rest of the receipt data is in cipher text. storage.
  • the exposed identifier is a global identifier defined in the programming language of the smart contract, it is difficult to modify the fields marked by the exposed identifier as long as the exposed identifier is written in the smart contract.
  • the transaction type has nothing to do with the programming language and can be selected by the user according to the actual needs.
  • the definition of the special event function is not necessarily based on the programming language. For example, when recording the special event function based on the special event function list, even in the smart contract A certain event function included is originally a special event function.
  • the code of a smart contract contains multiple event functions
  • the exposed identifier "plain” is located at the forefront of the smart contract code, so that all fields in the receipt data are marked as contract-level fields; at the same time, smart The contract contains the event currentPrice1 and event currentPrice2: Assuming that the From field is the exposed field corresponding to the transaction type, and the event currentPrice1 corresponds to the special event function defined in the special event function list, and the event currentPrice2 corresponds to the normal event function, then in the event currentPrice1 and In the logs Log1 and Log2 generated by the event currentPrice2, the From field contained in log Log1 is stored in plain text, and the From field contained in log Log2 is stored in cipher text; similarly, other fields in log Log1 that are exposed fields are also stored in plain text.
  • the storage and non-exposed fields are stored in cipher text, while all fields of the log Log2 are stored in cipher text. Moreover, if the event currentPrice2 is updated to correspond to the special event function by updating the list of special event functions, all the fields that belong to the exposed fields contained in the log Log2 will be stored in plain text, without the need to do anything to the smart contract code change.
  • the aforementioned type identifier can be used to indicate whether the event function included in the smart contract is a special event function.
  • the contract-level fields include all fields in the receipt data; at the same time, the smart contract contains the event currentPrice1 and the event currentPrice2: because the event currentPrice1 contains the same as before
  • the type identifier expose mentioned above makes the event currentPrice1 be marked as corresponding to the special event function, while the event currentPrice2 does not contain the type identifier expose, so that the event currentPrice2 is marked as corresponding to the normal event function, then the event currentPrice1 and event currentPrice2 In the generated logs Log1 and Log2, all the exposed fields corresponding to the transaction type in the log Log1 are stored in plain text, and all the fields contained in the log Log2 are stored in cipher text.
  • the type identifier and the exposed identifier are similar, they are both global identifiers defined in the programming language of the smart contract, but the exposed identifier acts on the contract-level fields and the type identifier acts on the event function, so that by In conjunction with the type identifier, you only need to add a single exposure identifier to set the contract-level fields mentioned above, and then you can flexibly mark the event functions that you want to store the contract-level fields in plaintext, especially when smart contracts When there are a large number of event functions included in the event function and the number of fields involved in the event function is large, you only need to add a "plain" similar to the above. There is no need to implement settings for each event function separately, which can simplify the code logic , Prevent mislabeling or missing labels.
  • the fields marked by the exposure identifier may include: event-level fields corresponding to at least one event defined in the smart contract, so that the first blockchain node can determine the at least one event when storing the receipt data.
  • a log generated by a special event function corresponding to an event, and the determined exposed fields belonging to the event-level field in the log are stored in plain text.
  • the above event-level fields can be set for at least some of the events, so that the exposed fields belonging to the event-level fields in the logs corresponding to these events are stored in plain text, and this part of the events Other fields in the corresponding log and the contents of receipts corresponding to other events are stored in cipher text. Take the From field as an example.
  • the event currentPrice1 does not add the exposed identifier "plain", it contains the content "from".
  • the content "from” corresponds to the From field and is used to indicate that the event currentPrice1 is The From field in the generated log needs to be stored in plain text, so the content "from” not only belongs to the above exposed identifier, but also indicates the From field that needs to be stored in plain text.
  • the From field is an event-level field, so that when the From field is an exposed field corresponding to the transaction type and the event currentPrice1 corresponds to a special event function, the log generated in the event currentPrice1 corresponds to In Logs, the From field will be stored in plain text, and other fields will be stored in cipher text.
  • the other event currentPrice2 contained in code example 8 since no exposure identifier is added for the event currentPrice2, regardless of whether the event currentPrice2 corresponds to a special event function or a normal event function, the generated log Logs are in the form of ciphertext storage.
  • the above keyword "from” indicates that the From field is set as an event-level field; however, in other embodiments, the specific field may not be specified.
  • the above code sample 5 can be adjusted to the following code sample 11:
  • all fields in the log generated by the event currentPrice1 can be used as the aforementioned event-level fields, such as the aforementioned From field and To field. , Topic field, Log Data field, etc.
  • the event currentPrice1 corresponds to a special event function
  • the log field that belongs to both the above event-level field and the exposed field corresponding to the transaction type can be determined from the log generated by the event currentPrice1, and stored in plain text; If the above-mentioned From field, To field, Topic field, Log Data field, etc. are all exposed fields, it is equivalent to storing all receipt content (such as the generated log) corresponding to the event currentPrice1 in plain text.
  • this specification can further identify the exposed identifier contained in the code of the smart contract corresponding to the transaction and the receipt content that meets the preset conditions in the receipt data, thereby simultaneously according to the special features contained in the smart contract.
  • the event function, the object indicated by the exposure identifier, and the content of the receipt meet the preset conditions, and determine the storage method of the receipt data. Therefore, the above step 308 can be improved as: the first blockchain node stores the receipt data, so that at least part of the receipt content in the log corresponding to the special event function is stored in plain text, and the rest of the receipt data Stored in a ciphertext form, the at least a part of the receipt content matches the object indicated by the exposure identifier and meets a preset condition.
  • This manual exposes the content of the receipt to a certain extent to realize the driver of the DAPP client or other function extensions.
  • this manual comprehensively considers the object indicated by the exposure identifier, the log generated by the special event function, and the preset conditions, and can accurately select the receipt content for plaintext storage, that is, at the same time satisfying "matching to the object indicated by the exposure identifier", The "logs generated by the special event function” and the receipt content "satisfy the preset conditions", so as to meet the above-mentioned function expansion requirements while ensuring that most user privacy can be protected.
  • the first blockchain node when it recognizes the special event function based on the information recorded on the blockchain network (such as the list of special event functions), it can perform the "special event function" after the smart contract has been created.
  • Update to adjust the storage method of receipt data such as changing the original receipt content stored in plain text to cipher text storage, or changing the original receipt content stored in cipher text to plain text storage.
  • this specification can further identify the user type of the transaction initiator and the exposed fields corresponding to the transaction type, so as to simultaneously according to the special event function contained in the smart contract, the user type of the transaction initiator and the transaction
  • the exposed field corresponding to the type determines the storage method of the receipt data. Therefore, the above step 308 can be improved as follows: the first blockchain node stores the receipt data, and when the transaction initiator belongs to the preset user type, the exposed field in the log corresponding to the special event function is in plaintext form The remaining content of the receipt data is stored in cipher text. It can be seen that the events contained in the smart contract can be divided into special event functions and ordinary event functions.
  • the log generated by the ordinary event function is stored in cipher text to achieve privacy protection; the log generated by the special event function needs to be stored in On the premise of meeting privacy protection requirements, at least a part of the log fields (such as the exposed fields described above) are stored in plain text, so that the content of this part of the log fields can be retrieved to drive the implementation of related operations.
  • this specification also further refers to the user type of the transaction initiator, which can reflect the privacy protection requirements of the transaction initiator for the receipt data, based on This privacy protection requirement determines the storage method of the exposed fields: for example, when the transaction initiator belongs to the preset user type, the exposed fields in the log generated by the special event function can be stored in plain text, otherwise they will be stored in cipher text .
  • the exposed fields that allow plaintext storage can be determined according to the differentiated needs of different types of transactions for privacy protection; further, the needs of different types of users for privacy protection It is not the same.
  • the transaction initiator belongs to the preset user type, it is allowed to trigger the DAPP client to implement related follow-up operations by exposing part of the receipt content to improve convenience, while other types of users may not be allowed to expose private information;
  • there are still differentiated privacy protection requirements in different scenarios which can be reflected in the storage process according to the type of event function contained in the smart contract called by the transaction
  • Different types of event functions have differentiated requirements for privacy protection.
  • the exposed fields involved in special event functions are stored in plain text, while the non-exposed fields involved in special event functions and all receipt fields involved in common event functions are all stored in Stored in ciphertext form, with high flexibility.
  • this manual can further identify the user type of the transaction initiator and the receipt content in the receipt data that meets the preset conditions, so as to at the same time according to the special event function contained in the smart contract and the transaction initiator’s
  • the user type and receipt content meet the preset conditions, and determine the storage method of the receipt data. Therefore, the above step 308 can be improved as: the first blockchain node stores the receipt data so that when the transaction initiator belongs to the preset user type, at least the log corresponding to the special event function meets the preset condition
  • One log field is stored in plain text, and the rest of the receipt data is stored in cipher text.
  • the receipt data is stored in cipher text.
  • this specification can further identify the exposed fields corresponding to the transaction type and the receipt content in the receipt data that meets the preset conditions, thereby simultaneously according to the special event function contained in the smart contract and the corresponding transaction type
  • the exposure field and the content of the receipt meet the preset conditions and determine the storage method of the receipt data. Therefore, the above step 308 can be improved as: the first blockchain node stores the receipt data, so that the exposed fields in the log corresponding to the special event function that meet the preset conditions are stored in plaintext, and the receipt data The rest of the content is stored in cipher text. It can be seen that the events contained in the smart contract can be divided into special event functions and ordinary event functions.
  • the log generated by the ordinary event function is stored in cipher text to achieve privacy protection; the log generated by the special event function needs to be stored in On the premise of meeting privacy protection requirements, at least a part of the log fields (such as the exposed fields described above) are stored in plain text, so that the content of this part of the log fields can be retrieved to drive the implementation of related operations.
  • this specification further refers to the predefined relevant conditions (ie, preset conditions), which can be used to judge and identify where the exposed fields are.
  • Privacy level with content When the exposed field meets the preset condition, it indicates that the privacy level is relatively low and can be stored in plain text. When the exposed field does not meet the preset condition, it indicates that the privacy level is relatively high and should be used. Stored in cipher text.
  • the exposed fields allowed to be stored in plaintext can be determined according to the differentiated requirements of different types of transactions for privacy protection; further, because different event functions often involve different information , So that different event functions correspond to different privacy protection requirements.
  • the privacy protection requirements of event functions related to the transfer amount are relatively high, and the privacy protection requirements of event functions related to evidence are relatively low (here only for example ;
  • the privacy protection requirement of the related event function may also be relatively low, and when the deposit content is more important, the privacy protection requirement of the related event function may also be relatively high
  • the event function with relatively low privacy protection requirements can be configured as the above special event function, and when the above exposed field is included in the log generated by the special event function, the receipt content corresponding to the exposed field is allowed to be exposed; furthermore, even For the exposed fields in the logs generated by the special event function, there are still differentiated privacy protection requirements in different scenarios.
  • the difference in privacy protection can be reflected in the storage process according to the satisfaction of the preset conditions by the exposed fields Modification requirements and processing:
  • the exposed fields that meet the preset conditions can be stored in plaintext, while the exposed fields or other receipt fields that do not meet the preset conditions are inevitable Stored in cipher text.
  • a special event function involves a deposit operation
  • the exposed field can be Store in plain text, otherwise store in cipher text.
  • this specification can further identify the exposed identifier contained in the code of the smart contract corresponding to the transaction, the user type of the transaction initiator, and the exposed field corresponding to the transaction type, so as to be based on the smart contract.
  • the special event function included, the object indicated by the exposure identifier, the user type of the transaction initiator, and the exposed field corresponding to the transaction type determine the storage method of the receipt data.
  • the above step 308 can be improved as: the first blockchain node stores the receipt data so that when the transaction initiator belongs to the preset user type, at least part of the receipt content in the log corresponding to the special event function It is stored in plain text, and the rest of the receipt data is stored in cipher text, and the at least a part of the receipt content matches the exposed field indicated by the exposure identifier.
  • the exposed identifier plain is added to the front of the smart contract code, so that after the smart contract code is executed, when the transaction initiator belongs to the preset user type, the receipt data is generated by the special event function
  • the log of the smart contract allows the contents of the receipt corresponding to the exposed field corresponding to the transaction type of the transaction to which the smart contract belongs to be stored in clear text.
  • the receipt data can be stored
  • the From field of all logs in the log is stored in plain text, and the To field is stored in cipher text. Then, subsequent retrieval operations can be performed on the receipt content in the From field, for example, the transaction volume initiated by an account can be counted.
  • the exposed identifier can indicate one or more fields, and these fields have corresponding receipt content in the receipt data.
  • the exposed fields corresponding to the transaction type may be one or more fields in the receipt data, and these fields have corresponding receipt content in the receipt data.
  • the receipt data contains a log corresponding to the special event function, which is actually part of the receipt content in the receipt data.
  • the exposed identifier is a global identifier defined in the programming language of the smart contract, it is difficult to modify the fields marked by the exposed identifier as long as the exposed identifier is written in the smart contract.
  • the user type depends on the transaction initiator and has nothing to do with the programming language, so that even when different transaction initiators call the same smart contract, the storage method (ciphertext or plaintext) of the receipt data may be different.
  • the transaction type can also be selected by the transaction initiator according to demand to indicate the actual needs of the transaction initiator.
  • the definition of special event functions is not necessarily based on programming languages.
  • the From field When the From field is further an exposed field corresponding to the transaction type, it can be preset at the transaction initiator In the case of the user type, when the first blockchain node stores the receipt data, all the receipt contents corresponding to the From field in the receipt data are allowed to be stored in plain text.
  • the code of the smart contract contains multiple event functions
  • the transaction can be identified by The user type to which the initiator belongs, the exposed field corresponding to the transaction type of the transaction, and the type of each event function are ordinary event functions or special event functions, so when the transaction initiator belongs to the preset user type and the contract-level field belongs to the exposed field , Store the receipt content corresponding to the contract-level field in the log generated by all special event functions in plain text.
  • the exposed identifier "plain" is located at the forefront of the smart contract code, so that all fields in the receipt data are marked as contract-level fields; at the same time, smart The contract contains the event currentPrice1 and the event currentPrice2: assuming that the event currentPrice1 corresponds to the special event function defined in the special event function list, and the event currentPrice2 corresponds to the normal event function, then the transaction initiator belongs to the preset user type and the From field is an exposed field In the case of the event currentPrice1 and event currentPrice2 respectively generated logs Log1 and Log2, the From field contained in log Log1 is stored in plain text, and the From field contained in log Log2 is stored in cipher text; similarly, the log Log1 is exposed Other fields of the field are also stored in plain text, non-exposed fields are stored in cipher text, and all fields in the log Log2 are stored in cipher text.
  • the aforementioned type identifier can be used to indicate whether the event function included in the smart contract is a special event function.
  • the contract-level fields include all fields in the receipt data; at the same time, the smart contract contains the event currentPrice1 and the event currentPrice2: because the event currentPrice1 contains the same as before
  • the type identifier expose mentioned above makes the event currentPrice1 be marked as corresponding to the special event function, and the event currentPrice2 does not contain the type identifier expose, so that the event currentPrice2 is marked as corresponding to the normal event function, then the event currentPrice2 is marked as corresponding to the normal event function.
  • the fields indicated by the exposure identifier may include: event-level fields corresponding to at least one event defined in the smart contract, so that the transaction initiator belongs to the preset user type and the event-level field belongs to the exposed field
  • the first blockchain node stores the part of the receipt content generated by the special event function that corresponds to the event-level field in plain text.
  • the above event-level fields can be set for at least some of the events, so that the contents of the receipts corresponding to the above-mentioned event-level fields in the logs generated by these events are stored in plain text, and this The content of the remaining receipts in the log generated by some events and the content of the receipts corresponding to the remaining events are stored in ciphertext. Take the From field as an example. In the above code sample 8, although the event currentPrice1 does not add the exposed identifier "plain", it contains the content "from”.
  • the content "from” corresponds to the From field and is used to indicate that the event currentPrice1 is
  • the From field in the generated log needs to be stored in plain text, so the content "from” not only belongs to the above exposed identifier, but also indicates the From field that needs to be stored in plain text.
  • the From field is an event-level field, so that when the transaction initiator belongs to the preset user type and the From field is an exposed field, when the event currentPrice1 corresponds to a special event function In the log Logs generated corresponding to the event currentPrice1, the From field will be stored in plain text, and other fields will be stored in cipher text.
  • the generated log Logs are in the form of ciphertext storage.
  • this code example 5 that is, for event-level fields, it is possible to identify whether the event functions contained in the smart contract are special event functions by means of a special event function list or type identifier. Repeat.
  • this specification can further identify the exposure identifier contained in the code of the smart contract corresponding to the transaction, the user type of the transaction initiator, and the receipt content that meets the preset conditions in the receipt data, thereby simultaneously
  • the storage method of the receipt data is determined. Therefore, the above step 308 can be improved as: the first blockchain node stores the receipt data so that when the transaction initiator belongs to the preset user type, at least part of the receipt content in the log corresponding to the special event function Stored in plain text, and the rest of the receipt data is stored in cipher text.
  • the at least a part of the receipt content matches the object indicated by the exposure identifier and meets preset conditions.
  • the transaction initiator does not belong to the preset In the case of the user type, the receipt data is stored in cipher text.
  • this specification can further identify the exposed identifier contained in the code of the smart contract corresponding to the transaction, the exposed field corresponding to the transaction type, and the receipt content in the receipt data that meets the preset conditions, thereby simultaneously According to the special event function contained in the smart contract, the object indicated by the exposure identifier, the exposure field corresponding to the transaction type, and the content of the receipt meet the preset conditions, determine the storage method of the receipt data.
  • the above step 308 can be improved as: the first blockchain node stores the receipt data, so that at least part of the receipt content in the log corresponding to the special event function is stored in plain text, and the rest of the receipt data It is stored in a ciphertext form, and the at least a part of the receipt content includes exposed fields that are marked by the exposure identifier and meet a preset condition.
  • the exposed identifier plain is added to the front of the code of the smart contract. From the perspective of the programming language, the exposed identifier plain indicates that after the code of the smart contract is executed, the generated receipt data All fields of are allowed to be stored in plain text, so subsequent retrieval operations can be performed on the receipt content in these fields. For example, for the From field, it can be used to count the transaction volume initiated by an account. By further combining dimensions such as transaction type, event function, and preset conditions, the storage scheme for receipt data may be different.
  • the From field in the receipt data may not all be stored in plain text, but the event currentPrice
  • the From field in the log generated by the event currentPrice is stored in plain text, otherwise it is stored in cipher text.
  • the exposed identifier is a global identifier defined in the programming language of the smart contract, it is difficult to modify the fields marked by the exposed identifier as long as the exposed identifier is written in the smart contract.
  • the preset conditions are not necessarily implemented based on the programming language in the smart contract where the identifier is exposed. Therefore, by calling the smart contract by different users or adjusting the preset conditions used, the limitation of the exposed identifier can be escaped. , Adjust the content of receipts that need to be stored in plain text or cipher text.
  • the transaction type has nothing to do with the programming language and can be selected by the user according to actual needs.
  • the definition of special event functions may not necessarily be implemented based on the programming language, such as recording special events based on the special event function list.
  • the event function even if an event function included in the smart contract originally belongs to a special event function, you can also update the original special event function to a normal event function by changing the list of special event functions to avoid the event
  • the log generated by the function is stored in plain text, or the original ordinary event function is updated to a special event function, so that at least part of the content in the log generated by the event function is stored in plain text.
  • the exposed fields in the log corresponding to the event currentPrice can be stored in plain text without the need to adjust the code example 2; for example, when the From field and the To field To expose fields, the From field and To field in the log generated by the event currentPrice will be stored in plain text, while the remaining fields will be stored in cipher text.
  • the fields marked by the exposed identifier "plain” are all fields in the receipt data, and these fields are contract-level fields . So that when the first blockchain node stores the receipt data, all the receipt contents corresponding to the contract-level field in the receipt data are allowed to be stored in plain text.
  • the From field is marked with the exposed identifier in Code Example 2, then the From field is the contract-level field mentioned above.
  • the From field is further an exposed field corresponding to the transaction type, the first blockchain node can be used When storing receipt data, all the receipt contents corresponding to the From field and meeting preset conditions in the receipt data are allowed to be stored in plain text.
  • the code of a smart contract contains multiple event functions
  • the exposed identifier "plain" is located at the forefront of the smart contract code, so that all fields in the receipt data are marked as contract-level fields; at the same time, smart The contract contains the event currentPrice1 and event currentPrice2: Assume that the From field is the exposed field corresponding to the transaction type, and the event currentPrice1 corresponds to the special event function defined in the special event function list, and the event currentPrice2 corresponds to the normal event function.
  • the From field contained in log Log1 is stored in plain text when the preset conditions are met, and the From field contained in log Log2 is stored in cipher text; similarly, the exposed fields in log Log1 Other fields are also stored in plain text, non-exposed fields are stored in cipher text, and all fields of log Log2 are stored in cipher text.
  • the event currentPrice2 is updated to correspond to the special event function after the special event function list is updated, then all the fields contained in the log Log2 that belong to the exposed fields and meet the preset conditions will be stored in plain text, without the need for smart Make any changes to the contract code.
  • the aforementioned type identifier can be used to indicate whether the event function contained in the smart contract is a special event function.
  • the contract-level fields include all fields in the receipt data; at the same time, the smart contract contains the event currentPrice1 and the event currentPrice2: because the event currentPrice1 contains the same as before
  • the type identifier expose mentioned above makes the event currentPrice1 be marked as corresponding to the special event function, while the event currentPrice2 does not contain the type identifier expose, so that the event currentPrice2 is marked as corresponding to the normal event function, then the event currentPrice1 and event currentPrice2 In the generated logs Log1 and Log2, all the exposed fields corresponding to the transaction type in the log Log1 are stored in plain text when the preset conditions are met, and all the fields contained in the log Log2 must be stored in cipher text.
  • the type identifier and the exposed identifier are similar, they are both global identifiers defined in the programming language of the smart contract, but the exposed identifier acts on the contract-level fields and the type identifier acts on the event function, so that by In conjunction with the type identifier, you only need to add a single exposure identifier to set the contract-level fields mentioned above, and then you can flexibly mark the event functions that you want to store the contract-level fields in plaintext, especially when smart contracts When there are a large number of event functions included in the event function and the number of fields involved in the event function is large, you only need to add a "plain" similar to the above. There is no need to implement settings for each event function separately, which can simplify the code logic , Prevent mislabeling or missing labels.
  • the fields marked by the exposure identifier may include: event-level fields corresponding to at least one event defined in the smart contract, so that the first blockchain node can determine the at least one event when storing the receipt data.
  • a log generated by a special event function corresponding to an event, and the determined exposed fields belonging to event-level fields and meeting preset conditions in the determined log are stored in plain text.
  • the above event-level fields can be set for at least some of the events, so that the exposed fields that belong to the event-level fields and meet the preset conditions in the logs corresponding to this part of the events are stored in plain text , And other fields in the log corresponding to this part of the event, and the content of the receipt corresponding to the remaining events are stored in cipher text.
  • From field Take the From field as an example.
  • the event currentPrice1 does not add the exposed identifier "plain", it contains the content "from”.
  • the content "from” corresponds to the From field and is used to indicate that the event currentPrice1 is
  • the From field in the generated log needs to be stored in plain text, so the content "from” not only belongs to the above exposed identifier, but also indicates the From field that needs to be stored in plain text.
  • the From field is an event-level field, so that when the From field is an exposed field corresponding to the transaction type and the event currentPrice1 corresponds to a special event function, the log generated in the event currentPrice1 corresponds to In Logs, the From field will be stored in plain text when the preset conditions are met, and in cipher text when the preset conditions are not met, and other fields must be stored in cipher text.
  • the generated log Logs are in the form of ciphertext storage.
  • the above keyword "from” indicates that the From field is set as an event-level field; however, in other embodiments, the specific field may not be specified.
  • the above code sample 11 by adding the exposure identifier "plain" before the event currentPrice1, all fields in the log generated by the event currentPrice1 can be used as the aforementioned event-level fields, such as the aforementioned From field, To field, Topic field, Log Data field, etc.
  • the event currentPrice1 corresponds to a special event function
  • the fields meet the preset conditions, they are stored in plain text; if the above-mentioned From field, To field, Topic field, Log Data field, etc. are all exposed fields and meet the preset conditions, then it is equivalent to the content of all receipts corresponding to the event currentPrice1 ( For example, the generated logs are stored in plain text.
  • this specification can further identify the exposed identifier contained in the code of the smart contract corresponding to the transaction, the user type of the transaction initiator, the exposed fields corresponding to the transaction type, and the receipt data that meet the preset requirements According to the content of the receipt of the condition, it is determined based on the special event function contained in the smart contract, the object indicated by the exposure identifier, the user type of the transaction initiator, the exposure field corresponding to the transaction type, and the content of the receipt to meet the preset conditions. How the receipt data is stored.
  • the above step 308 can be improved as: the first blockchain node stores the receipt data so that when the transaction initiator belongs to the preset user type, at least part of the receipt content in the log corresponding to the special event function Stored in plain text, and the remaining content of the receipt data is stored in cipher text, and the at least part of the receipt content matches the exposure field indicated by the exposure identifier and meets a preset condition.
  • the exposed identifier plain is added to the front of the smart contract code, so that after the smart contract code is executed, when the transaction initiator belongs to the preset user type, the receipt data is generated by the special event function
  • the log allows the exposed field corresponding to the transaction type of the transaction to which the smart contract belongs and the content of the receipt meeting preset conditions is stored in clear text.
  • the From field of all logs in the receipt data can be stored in plain text when the preset conditions are met, and the To field is stored in cipher text. Then, subsequent retrieval operations can be performed on the receipt content in the From field, for example, a certain account can be counted The volume of transactions initiated, etc.
  • the exposed identifier is a global identifier defined in the programming language of the smart contract, it is difficult to modify the fields marked by the exposed identifier as long as the exposed identifier is written in the smart contract.
  • the user type depends on the transaction initiator and has nothing to do with the programming language, so that even when different transaction initiators call the same smart contract, the storage method (ciphertext or plaintext) of the receipt data may be different.
  • the transaction type can also be selected by the transaction initiator according to demand to indicate the actual needs of the transaction initiator.
  • the preset conditions can be selected by the transaction initiator according to actual needs, regardless of the programming language. At the same time, the definition of special event functions is not necessarily based on programming languages.
  • the From field When the From field is further an exposed field corresponding to the transaction type, it can be preset at the transaction initiator In the case of the user type, when the first blockchain node stores receipt data, all receipt content in the receipt data that corresponds to the From field and meets the preset conditions is allowed to be stored in plain text.
  • the code of the smart contract contains multiple event functions
  • the respective Logs fields generated by the multiple event functions there may be the receipt content corresponding to the contract-level field;
  • the transaction can be identified by The user type to which the initiator belongs, the exposed fields corresponding to the transaction type of the transaction, the type of each event function is ordinary event function or special event function, and the content of the receipt meets the preset conditions, so that the transaction initiator belongs to the preset user type
  • the contract-level field is an exposed field, the contents of the receipt corresponding to the contract-level field and satisfying the preset conditions in the logs generated by all special event functions are stored in plain text.
  • the exposed identifier "plain" is located at the forefront of the smart contract code, so that all fields in the receipt data are marked as contract-level fields; at the same time, smart The contract contains the event currentPrice1 and the event currentPrice2: assuming that the event currentPrice1 corresponds to the special event function defined in the special event function list, and the event currentPrice2 corresponds to the normal event function, then the transaction initiator belongs to the preset user type and the From field is an exposed field
  • the From field contained in the log Log1 is stored in plain text when the preset conditions are met, and in cipher text when the preset conditions are not met
  • the From field contained in log Log2 must be stored in cipher text; similarly, other fields in log Log1 that are exposed fields are also stored in plain text when the preset conditions are met, and non-exposed fields are stored in cipher text.
  • All the fields of the log Log2 are stored in cipher text. Moreover, if the event currentPrice2 is updated to correspond to the special event function after updating the list of special event functions, all the fields belonging to the exposed fields contained in the log Log2 can be stored in plain text under the condition that the preset conditions are met. If the preset conditions are not met, it is stored in ciphertext form, without any changes to the code of the smart contract.
  • the aforementioned type identifier can be used to indicate whether the event function included in the smart contract is a special event function.
  • the contract-level fields include all fields in the receipt data; at the same time, the smart contract contains the event currentPrice1 and the event currentPrice2: because the event currentPrice1 contains the same as before
  • the type identifier expose mentioned above makes the event currentPrice1 be marked as corresponding to the special event function, and the event currentPrice2 does not contain the type identifier expose, so that the event currentPrice2 is marked as corresponding to the normal event function, then the event currentPrice2 is marked as corresponding to the normal event function.
  • the fields indicated by the exposure identifier may include: event-level fields corresponding to at least one event defined in the smart contract, so that the transaction initiator belongs to the preset user type and the event-level field belongs to the exposed field
  • the first blockchain node stores the part of the receipt content generated by the special event function that corresponds to the event-level field and meets the preset condition in plain text.
  • the above event-level fields can be set for at least some of the events, so that the contents of the receipts that correspond to the above-mentioned event-level fields and meet the preset conditions in the logs generated by this part of the events are in plain text
  • the content of the remaining receipts in the log generated by this part of the event and the content of the receipt corresponding to the remaining events are stored in the form of ciphertext. Take the From field as an example. In the above code sample 8, although the event currentPrice1 does not add the exposed identifier "plain", it contains the content "from”.
  • the content "from” corresponds to the From field and is used to indicate that the event currentPrice1 is The From field in the generated log needs to be stored in plain text, so the content "from” not only belongs to the above exposed identifier, but also indicates the From field that needs to be stored in plain text.
  • the From field is an event-level field, so that when the transaction initiator belongs to the preset user type and the From field is an exposed field, when the event currentPrice1 corresponds to a special event function In the log Logs corresponding to the event currentPrice1, the From field is stored in plain text when the preset conditions are met, and stored in cipher text when the preset conditions are not met, and other fields must be stored in cipher text Form storage.
  • the generated log Logs are in the form of ciphertext storage.
  • the embodiment corresponding to this code example 8 that is, for event-level fields, it is possible to identify whether the event functions contained in the smart contract are special event functions by means of a special event function list or type identifier. Repeat.
  • each of the above-expanded embodiments can also implement corresponding logic functions through chain codes, or adopt a combination of chain codes and system contracts.
  • the embodiment shown in FIG. 3 uses the receipt data storage logic related to the event function contained in the smart contract, and the expanded embodiment described above further considers at least one of the following factors: The object marked by the symbol, the user type of the transaction initiator, the transaction type, and the receipt content that meets the preset conditions in the receipt data. One or more of the above factors can be combined with the user type to obtain the corresponding receipt data storage logic.
  • the receipt data storage logic When the receipt data storage logic is related to the object indicated by the exposure identifier, the receipt data storage logic includes logic for storing the content of the receipt based on the exposure identifier, and the logic is used to instruct the first blockchain node: to indicate the exposure identifier The corresponding receipt content should be stored in the fields of, and fields not marked by the exposed identifier.
  • the receipt data storage logic When the receipt data storage logic is related to the user type of the transaction initiator, the receipt data storage logic includes: identification logic for the user type.
  • the user type identification logic is used to instruct the first blockchain node to identify the user type of the transaction initiator.
  • the system contract can record the association relationship between the predefined external account and the user type, or the system contract can record the correspondence between the value of the user type field and the user type. For details, please refer to the relevant description of identifying user types above, which will not be repeated here.
  • the receipt data storage logic When the receipt data storage logic is related to the transaction type of the transaction, the receipt data storage logic includes: an identification logic for the transaction type.
  • the identification logic of the transaction type is used to instruct the first blockchain node: to identify the type of transaction initiated by the transaction initiator. For example, according to the value of the type field contained in the exchange, determine the transaction type corresponding to the transaction. For details, please refer to the relevant description of identifying transaction types above, which will not be repeated here.
  • the receipt data storage logic When the receipt data storage logic is related to the receipt content that meets the preset condition in the receipt data, the receipt data storage logic includes: logic for determining the preset condition.
  • the determination logic of the preset condition is used to instruct the first blockchain node to obtain the preset condition applicable to the content of the receipt corresponding to the object indicated by the exposure identifier. For example, obtain general conditions applicable to all receipt fields, or obtain special conditions applicable to the field of the receipt content corresponding to the object indicated by the exposure identifier. For details, please refer to the relevant description of the preset conditions above, which will not be repeated here.
  • the receiving unit 61 receives an encrypted transaction corresponding to the smart contract
  • a decryption unit 62 decrypting the transaction in a trusted execution environment to obtain the smart contract, the smart contract including a special event function;
  • the execution unit 63 executes the smart contract in the trusted execution environment to obtain receipt data, where the receipt data includes a log corresponding to the special event function;
  • the storage unit 64 stores the receipt data so that at least a part of the receipt content in the log corresponding to the special event function is stored in plain text, and the remaining content of the receipt data is stored in cipher text.
  • the at least a part of the receipt content matches an exposure log field corresponding to the special event function.
  • the special event function includes the marked exposed log field; or, the special event function includes a marked encrypted log field, and the exposed log field is another log field.
  • determining the exposure log field corresponding to the special event function includes:
  • mapping relationship between the predefined special event function and the exposed log field or obtain the mapping relationship between the predefined special event function and the encrypted log field;
  • the exposure log field corresponding to the special event function is determined.
  • mapping relationship is recorded in a system contract.
  • the event function in the smart contract includes a type identifier, and the type identifier is used to mark the event function as a special event function.
  • the event function included in the smart contract is in the special function list recorded on the blockchain, the event function included in the smart contract is determined to be a special event function.
  • the storage unit 64 is specifically used for:
  • the receipt data is stored so that the transaction initiator belongs to the preset user type, at least part of the receipt content in the log corresponding to the special event function is stored in plain text, and the rest of the receipt data is in cipher text. storage.
  • the user type to which the transaction initiator belongs is determined in the following manner:
  • the external account includes a user type field recorded on the blockchain, and the value of the user type field corresponds to the user type.
  • the user type is configured to be associated with the external account, so that the association relationship between the user type and the external account is recorded in the blockchain.
  • Optional also includes:
  • the changing unit 65 changes the user type corresponding to the external account according to the change request initiated by the management user.
  • the at least part of the receipt content stored in plaintext meets at least one of the following rules:
  • the at least a part of the receipt content matches the object indicated by the exposed identifier contained in the code of the smart contract;
  • the at least a part of the receipt content corresponds to the exposed field corresponding to the transaction type of the transaction;
  • the information contained in the at least part of the receipt content meets a preset condition.
  • the smart contract corresponding to the transaction received by the receiving unit 61 includes:
  • the smart contract written in the high-level language and the smart contract in bytecode form have the same or corresponding exposure identifier.
  • the objects indicated by the exposure identifier include: receipt fields and/or state variables.
  • the object indicated by the exposure identifier includes at least one of the following: a contract-level object applicable to all events defined in the smart contract, and an event-level object corresponding to at least one event defined in the smart contract Object.
  • the transaction includes a transaction type field, and the value of the transaction type field is used to indicate the corresponding transaction type.
  • a predefined mapping relationship between the transaction type and the exposed field is stored in the blockchain, and the mapping relationship is used to determine the exposed field corresponding to the transaction type of the transaction.
  • the transaction type of the transaction includes: deposit certificate type, asset transfer type, contract creation type, contract call type.
  • the preset condition includes at least one of the following: the corresponding receipt content includes the preset content, and the value of the corresponding receipt content belongs to the preset numerical interval.
  • the preset conditions include general conditions corresponding to all receipt fields in the receipt data; or,
  • the preset condition includes a dedicated condition corresponding to each receipt field in the receipt data.
  • the preset condition is in the transaction; or,
  • the preset condition is located in the smart contract corresponding to the transaction, or in another smart contract called by the smart contract corresponding to the transaction; or,
  • the preset conditions are located in the system contract or chain code.
  • the storage unit 64 is specifically configured to:
  • the code of the system contract is executed to store at least a part of the receipt content in the log corresponding to the special event function in plaintext when the smart contract contains a special event function, and the rest of the receipt data is stored in plain text. Stored in cipher text.
  • the system contract includes: a preset system contract recorded in the genesis block, or an updated system contract corresponding to the preset system contract.
  • the storage unit 64 is specifically configured to:
  • the storage function code is executed outside the trusted execution environment to store the receipt data in an external storage space outside the trusted execution environment.
  • the key used by the first blockchain node to encrypt the receipt data includes: a key of a symmetric encryption algorithm or a key of an asymmetric encryption algorithm.
  • the key of the symmetric encryption algorithm includes an initial key provided by the client; or, the key of the symmetric encryption algorithm includes a derived key generated by the initial key and an influence factor.
  • the transaction is encrypted by the initial key, and the initial key is encrypted by a public key of an asymmetric encryption algorithm; the decryption unit 62 is specifically configured to:
  • the initial key is generated by the client; or, the initial key is sent to the client by the key management server.
  • the impact factor is related to the transaction.
  • the impact factor includes: a designated bit of the hash value of the transaction.
  • a programmable logic device Programmable Logic Device, PLD
  • FPGA Field Programmable Gate Array
  • HDL Hardware Description Language
  • ABEL Advanced Boolean Expression Language
  • AHDL Altera Hardware Description Language
  • HDCal JHDL
  • Lava Lava
  • Lola MyHDL
  • PALASM RHDL
  • Verilog Verilog
  • the controller can be implemented in any suitable manner.
  • the controller can take the form of, for example, a microprocessor or a processor and a computer-readable medium storing computer-readable program codes (such as software or firmware) executable by the (micro)processor. , Logic gates, switches, application specific integrated circuits (ASICs), programmable logic controllers and embedded microcontrollers. Examples of controllers include but are not limited to the following microcontrollers: ARC625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicon Labs C8051F320, the memory controller can also be implemented as part of the memory control logic.
  • controller in addition to implementing the controller in a purely computer-readable program code manner, it is entirely possible to program the method steps to make the controller use logic gates, switches, application specific integrated circuits, programmable logic controllers and embedded The same function can be realized in the form of a microcontroller, etc. Therefore, such a controller can be regarded as a hardware component, and the devices included in it for implementing various functions can also be regarded as a structure within the hardware component. Or even, the device for realizing various functions can be regarded as both a software module for realizing the method and a structure within a hardware component.
  • a typical implementation device is a computer.
  • the computer may be, for example, a personal computer, a laptop computer, a cell phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or Any combination of these devices.
  • the embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.
  • a computer-usable storage media including but not limited to disk storage, CD-ROM, optical storage, etc.
  • program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types.
  • This specification can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network.
  • program modules can be located in local and remote computer storage media including storage devices.
  • These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device.
  • the device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.
  • These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment.
  • the instructions provide steps for implementing functions specified in a flow or multiple flows in the flowchart and/or a block or multiple blocks in the block diagram.
  • the computer includes one or more processors (CPU), input/output interfaces, network interfaces, and memory.
  • the memory may include non-permanent memory in computer readable media, random access memory (RAM) and/or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). Memory is an example of computer readable media.
  • RAM random access memory
  • ROM read-only memory
  • flash RAM flash memory
  • Computer-readable media include permanent and non-permanent, removable and non-removable media, and information storage can be realized by any method or technology.
  • the information can be computer-readable instructions, data structures, program modules, or other data.
  • Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disc (DVD) or other optical storage, Magnetic cassettes, magnetic disk storage, quantum memory, graphene-based storage media or other magnetic storage devices or any other non-transmission media can be used to store information that can be accessed by computing devices. According to the definition in this article, computer-readable media does not include transitory media, such as modulated data signals and carrier waves.
  • first, second, third, etc. may be used in one or more embodiments of this specification to describe various information, the information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other.
  • first information may also be referred to as second information, and similarly, the second information may also be referred to as first information.
  • word “if” as used herein can be interpreted as "when” or “when” or "in response to determination”.

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • Databases & Information Systems (AREA)
  • General Health & Medical Sciences (AREA)
  • Computer Hardware Design (AREA)
  • Computer Security & Cryptography (AREA)
  • Software Systems (AREA)
  • Health & Medical Sciences (AREA)
  • Bioethics (AREA)
  • Computing Systems (AREA)
  • Data Mining & Analysis (AREA)
  • Financial Or Insurance-Related Operations Such As Payment And Settlement (AREA)

Abstract

一种基于事件函数类型的收据存储方法和节点，该方法可以包括：第一区块链节点接收经过加密的调用智能合约的交易（302）；第一区块链节点在可信执行环境中解密所述交易以获得所述智能合约，所述智能合约包含特殊事件函数（304）；第一区块链节点在所述可信执行环境中执行所述智能合约，得到收据数据，所述收据数据包含对应于所述特殊事件函数的日志（306）；第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储（308）。

Description

基于事件函数类型的收据存储方法和节点 技术领域
本说明书一个或多个实施例涉及终端技术领域，尤其涉及一种基于事件函数类型的收据存储方法和节点。
背景技术
区块链技术构建在传输网络(例如点对点网络)之上。传输网络中的网络节点利用链式数据结构来验证与存储数据，并采用分布式节点共识算法来生成和更新数据。
目前企业级的区块链平台技术上最大的两个挑战就是隐私和性能，往往这两个挑战很难同时解决。大多解决方案都是通过损失性能换取隐私，或者不大考虑隐私去追求性能。常见的解决隐私问题的加密技术，如同态加密(Homomorphic encryption)和零知识证明(Zero-knowledge proof)等复杂度高，通用性差，而且还可能带来严重的性能损失。
可信执行环境(Trusted Execution Environment,TEE)是另一种解决隐私问题的方式。TEE可以起到硬件中的黑箱作用，在TEE中执行的代码和数据操作***层都无法偷窥，只有代码中预先定义的接口才能对其进行操作。在效率方面，由于TEE的黑箱性质，在TEE中进行运算的是明文数据，而不是同态加密中的复杂密码学运算，计算过程效率没有损失，因此与TEE相结合可以在性能损失较小的前提下很大程度上提升区块链的安全性和隐私性。目前工业界十分关注TEE的方案，几乎所有主流的芯片和软件联盟都有自己的TEE解决方案，包括软件方面的TPM(Trusted Platform Module，可信赖平台模块)以及硬件方面的Intel SGX(Software Guard Extensions,软件保护扩展)、ARM Trustzone(信任区)和AMD PSP(Platform Security Processor，平台安全处理器)。
发明内容
有鉴于此，本说明书一个或多个实施例提供一种基于事件函数类型的收据存储方法和节点。
为实现上述目的，本说明书一个或多个实施例提供技术方案如下：
根据本说明书一个或多个实施例的第一方面，提出了一种基于事件函数类型的收据存储方法，包括：
第一区块链节点接收经过加密的对应于智能合约的交易；
第一区块链节点在可信执行环境中解密所述交易以获得所述智能合约，所述智能合约包含特殊事件函数；
第一区块链节点在所述可信执行环境中执行所述智能合约，得到收据数据，所述收据数据包含对应于所述特殊事件函数的日志；
第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储。
根据本说明书一个或多个实施例的第二方面，提出了一种基于事件函数类型的收据存储节点，包括：
接收单元，接收经过加密的对应于智能合约的交易；
解密单元，在可信执行环境中解密所述交易以获得所述智能合约，所述智能合约包含特殊事件函数；
执行单元，在所述可信执行环境中执行所述智能合约，得到收据数据，所述收据数据包含对应于所述特殊事件函数的日志；
存储单元，存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储。
根据本说明书一个或多个实施例的第三方面，提出了一种电子设备，包括：
处理器；
用于存储处理器可执行指令的存储器；
其中，所述处理器通过运行所述可执行指令以实现如第一方面所述的方法。
根据本说明书一个或多个实施例的第四方面，提出了一种计算机可读存储介质，其上存储有计算机指令，该指令被处理器执行时实现如第一方面所述方法的步骤。
附图说明
图1是一示例性实施例提供的一种创建智能合约的示意图。
图2是一示例性实施例提供的一种调用智能合约的示意图。
图3是一示例性实施例提供的一种基于事件函数类型的收据存储方法的流程图。
图4是一示例性实施例提供的一种在区块链节点上实现隐私保护的示意图。
图5是一示例性实施例提供的一种通过***合约和链代码实现区块链网络的功能逻辑的示意图。
图6是一示例性实施例提供的一种基于事件函数类型的收据存储节点的框图。
具体实施方式
这里将详细地对示例性实施例进行说明，其示例表示在附图中。下面的描述涉及附图时，除非另有表示，不同附图中的相同数字表示相同或相似的要素。以下示例性实施例中所描述的实施方式并不代表与本说明书一个或多个实施例相一致的所有实施方式。相反，它们仅是与如所附权利要求书中所详述的、本说明书一个或多个实施例的一些方面相一致的装置和方法的例子。
需要说明的是：在其他实施例中并不一定按照本说明书示出和描述的顺序来执行相应方法的步骤。在一些其他实施例中，其方法所包括的步骤可以比本说明书所描述的更多或更少。此外，本说明书中所描述的单个步骤，在其他实施例中可能被分解为多个步骤进行描述；而本说明书中所描述的多个步骤，在其他实施例中也可能被合并为单个步骤进行描述。
区块链一般被划分为三种类型：公有链(Public Blockchain)，私有链(Private Blockchain)和联盟链(Consortium Blockchain)。此外，还有多种类型的结合，比如私有链+联盟链、联盟链+公有链等不同组合形式。其中去中心化程度最高的是公有链。公有链以比特币、以太坊为代表，加入公有链的参与者可以读取链上的数据记录、参与交易以及竞争新区块的记账权等。而且，各参与者(即节点)可自由加入以及退出网络，并进行相关操作。私有链则相反，该网络的写入权限由某个组织或者机构控制，数据读取权限受组织规定。简单来说，私有链可以为一个弱中心化***，参与节点具有严格限 制且少。这种类型的区块链更适合于特定机构内部使用。联盟链则是介于公有链以及私有链之间的区块链，可实现“部分去中心化”。联盟链中各个节点通常有与之相对应的实体机构或者组织；参与者通过授权加入网络并组成利益相关联盟，共同维护区块链运行。
不论是公有链、私有链还是联盟链，都可能提供智能合约的功能。区块链上的智能合约是在区块链***上可以被交易触发执行的合约。智能合约可以通过代码的形式定义。
以以太坊为例，支持用户在以太坊网络中创建并调用一些复杂的逻辑，这是以太坊区别于比特币区块链技术的最大挑战。以太坊作为一个可编程区块链的核心是以太坊虚拟机(EVM)，每个以太坊节点都可以运行EVM。EVM是一个图灵完备的虚拟机，这意味着可以通过它实现各种复杂的逻辑。用户在以太坊中发布和调用智能合约就是在EVM上运行的。实际上，虚拟机直接运行的是虚拟机代码(虚拟机字节码，下简称“字节码”)。部署在区块链上的智能合约可以是字节码的形式。
例如图1所示，Bob将一个包含创建智能合约信息的交易发送到以太坊网络后，节点1的EVM可以执行这个交易并生成对应的合约实例。图中1中的“0x6f8ae93…”代表了这个合约的地址，交易的data字段保存的可以是字节码，交易的to字段为空。节点间通过共识机制达成一致后，这个合约成功创建，并且可以在后续过程中被调用。合约创建后，区块链上出现一个与该智能合约对应的合约账户，并拥有一个特定的地址，合约代码将保存在该合约账户中。智能合约的行为由合约代码控制。换句话说，智能合约使得区块链上产生包含合约代码和账户存储(Storage)的虚拟账户。
如图2所示，仍以以太坊为例，Bob将一个用于调用智能合约的交易发送到以太坊网络后，某一节点的EVM可以执行这个交易并生成对应的合约实例。图中2中交易的from字段是交易发起方(即Bob)的账户的地址，to字段中的“0x6f8ae93…”代表了被调用的智能合约的地址，value字段在以太坊中是以太币的值，交易的data字段保存的调用智能合约的方法和参数。智能合约以规定的方式在区块链网络中每个节点独立的执行，所有执行记录和数据都保存在区块链上，所以当交易完成后，区块链上就保存了无法篡改、不会丢失的交易凭证。
区块链网络中的节点在执行Bob发起的交易后，会生成相应的收据(receipt)数据，以用于记录该交易相关的收据信息。以以太坊为例，节点执行交易所得的收据数据可以包括如下内容：
Result字段，表示交易的执行结果；
Gas used字段，表示交易消耗的gas值；
Logs字段，表示交易产生的日志，日志可以进一步包括From字段、To字段、Topic字段和Log data字段等，其中From字段表示调用的发起方的账户地址、To字段表示被调用对象(如智能合约)的账户地址、Topic字段表示日志的主题、Log data字段表示日志数据；
Output字段，表示交易的输出。
其中，日志是以太坊中提供的一项功能。在智能合约的代码的运行过程中，可以记录代码所含的各个事件所产生的日志。日志允许记录事件的细节，比如上述的From字段、To字段可以表明交易涉及的双方账户，Topic字段可以包含事件所引用的状态变量等在代码执行后的取值等。因此，日志除了可以作为交易在区块链上执行后的相关证据，还可以用于驱动相关操作。例如，可以使用JavaScript的回调函数监听事件，当事件触发时可以产生相应的日志，因而通过检索日志内容，可以在检索到预设日志内容时驱动DAPP(Decentralized Application，分布式应用)客户端执行相关处理操作等。
在相关技术中，TEE内生成的收据数据的全部内容均被当作需要隐私保护的数据而加密存储在区块链上。所述区块链，是存储在节点的数据库中特定逻辑组织而成的数据集合。所述数据库，如后所述，其物理载体可以存储介质，例如持久性存储介质。当收据数据所含的日志被加密存储时，针对日志的检索操作可能无法正常实施，从而影响到上述DAPP客户端对相关处理操作的执行。
以下结合图3所示说明本申请一基于事件函数类型的收据存储方法的实施例的实现过程：
步骤302，第一区块链节点接收经过加密的对应于智能合约的交易。
在一实施例中，用户可以直接在第一区块链节点上生成交易；或者，用户可以在客户端上生成交易，并通过客户端将该交易发送至第一区块链节点；或者，客户端可以将上述交易发送至第二区块链节点，并由第二区块链节点将该交易发送至第一区块链节点。
在一实施例中，当交易用于调用智能合约时，交易内容可以包括被调用的智能合约的账户地址、需要传入的方法和参数等。
步骤304，第一区块链节点在可信执行环境中解密所述交易以获得所述智能合约，所述智能合约包含特殊事件函数。
在一实施例中，智能合约可以包含一个或多个事件，每一事件用于实现预定义的相关处理逻辑。智能合约所含的每一事件被调用执行后，均会生成对应的Logs字段，比如当智能合约包含事件1和事件2时，事件1可以生成对应的Logs字段、事件2可以生成对应的Logs字段，使得该智能合约对应的收据数据同时包含多个Logs字段。
在一实施例中，智能合约所含的事件可以分为特殊事件函数和普通事件函数，其中：普通事件函数所产生的日志采用密文形式进行存储，以实现隐私保护；特殊事件函数所产生的日志则需要在满足隐私保护需求的前提下，将至少一部分日志字段以明文形式进行存储，从而可以针对该部分日志字段的内容实施检索，以驱动相关操作的实施。
在一实施例中，特殊事件函数可以为区块链网络中预定义的全局事件函数。比如在区块链网络的链代码或***合约中，可以记录属于“特殊事件函数”的的事件函数，譬如可以记录在特殊事件函数列表中；相应地，通过将智能合约中包含的事件函数与上述的特殊事件函数列表进行对比，可以确定智能合约包含的事件函数是否为上述的特殊事件函数。
在一实施例中，特殊事件函数可以为智能合约中自定义的任意函数，并通过在智能合约中添加针对事件函数的类型标识符，可以将该事件函数标记为特殊事件函数。以Solidity语言为例，智能合约包含的事件函数的代码示例如下：
Event buy_candy1 expose(who,candy_num)；
Event buy_candy2_1(who,candy_num)；
Event buy_candy2_2(“from”,who,candy_num)；
在上述代码示例中，智能合约定义了3个事件：事件buy_candy1、事件buy_candy2_1和事件buy_candy2_2。
通过在事件buy_candy1中添加类型标识符“expose”，可以将该事件buy_candy1标记为上述的特殊事件函数；相应的，由于事件buy_candy2中并未包含类型标识符“expose”，因而事件buy_candy2为普通事件函数、而非上述的特殊事件函数。
而事件buy_candy2_2虽然未添加类型标识符“expose”，但是包含了内容“from”，该内容“from”对应于From字段，用于表明事件buy_candy2_2所产生日志中的From字段需要以明文/密文形式存储，因而该内容“from”既表明了事件buy_candy2_2属于 特殊事件函数，又标明了需要明文/密文存储的字段(需要明文存储的字段即下文的暴露日志字段，需要密文存储的字段即下文的加密日志字段)。
以太坊支持的高级语言很多，如Solidity、Serpent、LLL语言等，均可以包含上述的类型标识符。通过编译器可以将高级语言编写的智能合约编译为相应的字节码，第一区块链节点最终在EVM虚拟机中执行字节码形式的智能合约。那么，上述的类型标识符在高级语言和字节码形式的智能合约代码中可以相同，或者高级语言的智能合约代码中为第一类型标识符、字节码形式的智能合约代码中为第二类型标识符，第一类型标识符与第二类型标识符之间可以相互对应。
在一实施例中，通过对交易内容进行加密，可使上述经过加密的交易处于隐私保护的状态，避免交易内容发生暴露。譬如，交易内容中可能包含交易发起方的账户地址、交易目标的账户地址等信息，通过加密处理可以确保这些交易内容均无法被直接读取。
在一实施例中，上述交易可以通过对称加密算法的方式进行加密，也可以采用非对称算法的方式进行加密。对称加密采用的加密算法，例如是DES算法，3DES算法，TDEA算法，Blowfish算法，RC5算法，IDEA算法等。非对称加密算法，例如是RSA、Elgamal、背包算法、Rabin、D-H、ECC(椭圆曲线加密算法)等。
在一实施例中，上述交易可以通过对称加密算法结合非对称加密算法的方式进行加密。以客户端将上述交易提交至第一区块链节点为例，客户端可以采用对称加密算法加密交易内容，即采用对称加密算法的密钥加密交易内容，并用非对称加密算法加密对称加密算法中采用的密钥，譬如采用非对称加密算法的公钥加密对称加密算法中采用的密钥。这样，第一区块链节点接收到加密的交易后，可以先采用非对称加密算法的私钥进行解密，得到对称加密算法的密钥，进而用对称加密算法的密钥解密得到交易内容。
当交易用于调用智能合约时，可以是多重嵌套结构的调用。例如，交易直接调用智能合约1，而该智能合约1的代码调用了智能合约2，且智能合约2中的代码指向了智能合约3的合约地址，使得交易实际上间接调用了智能合约3的代码，而智能合约3中包括某一事件函数。这样，相当于智能合约1中包含了该事件函数。具体实现过程与上述过程类似，在此不再赘述。
步骤306，第一区块链节点在所述可信执行环境中执行所述智能合约，得到收据数据，所述收据数据包含对应于所述特殊事件函数的日志。
如前所述，第一区块链节点在执行智能合约的代码时，针对代码所含的每一事件函 数，将分别生成对应的Logs字段，即分别生成对应于每一事件函数的日志。通过确定出特殊事件函数，可以进一步确定出特殊事件函数对应的日志，从而将特殊事件函数对应的至少一部分日志字段采用明文形式进行存储。
在一实施例中，比如在以太坊中，第一区块链节点接收到客户端发来的调用智能合约的交易后，可以检查交易是否有效、格式是否正确，验证交易的签名是否合法等。
一般来说，以太坊中的节点一般也是争夺记账权的节点，因此，第一区块链节点作为争夺记账权的节点可以在本地执行所述交易。如果争夺记账权的节点中的一个在本轮争夺记账权的过程中胜出，则成为记账节点。第一区块链节点如果在本轮争夺记账权的过程中胜出，就成为记账节点；当然，如果第一区块链节点如果在本轮争夺记账权的过程中没有胜出，则不是记账节点，而其它节点可能成为记账节点。
智能合约类似于面向对象编程中的类，执行的结果生成对应该智能合约的合约实例，类似于生成类对应的对象。执行交易中用于创建智能合约的代码的过程，会创建合约账户，并在账户空间中部署合约。以太坊中，智能合约账户的地址是由发送者的地址(如图1-2中的“0xf5e…”)和交易随机数(nonce)作为输入，通过加密算法生成的，比如图1-2中的合约地址“0x6f8ae93…”即由发送者的地址“0xf5e…”和交易中的nonce经加密算法生成。
一般的，采用工作量证明(Proof of Work,POW)以及股权证明(Proof of Stake，POS)、委任权益证明(Delegated Proof of Stake，DPOS)等共识算法的支持智能合约的区块链网络中，争夺记账权的节点都可以在接收到包含创建智能合约的交易后执行所述交易。争夺记账权的节点中可能其中一个在本轮争夺记账权的过程中胜出，成为记账节点。记账节点可以将该包含智能合约的交易与其它交易一起打包并生成新的区块，并将生成的新的区块发送至其它节点进行共识。
对于采用实用拜占庭容错(Practical Byzantine Fault Tolerance，PBFT)等机制的支持智能合约的区块链网络中，具有记账权的节点在本轮记账前已经商定好。因此，第一区块链节点接收到上述交易后，如果自身不是本轮的记账节点，则可以将该交易发送至记账节点。对于本轮的记账节点(可以是第一区块链节点)，在将该交易打包并生成新区块的过程中或者之前，或在将该交易与其它交易一起打包并生成新区块的过程中或者之前，可以执行该交易。所述记账节点将该交易打包(或还包括其它交易一起打包)并生成新的区块后，将生成的新的区块或者区块头发送至其它节点进行共识。
如上所述，采用POW机制的支持智能合约的区块链网络中，或者采用POS、DPOS、PBFT机制的支持智能合约的区块链网络中，本轮的记账节点都可以将该交易打包并生成新的区块，并将生成的新的区块后区块头发送至其它节点进行共识。如果其它节点接收到所述区块后经验证没有问题，可以将该新的区块追加到原有的区块链末尾，从而完成记账过程，达成共识；若交易用于创建智能合约，则完成了智能合约在区块链网络上的部署，若交易用于调用智能合约，则完成了智能合约的调用和执行。其它节点验证记账节点发来的新的区块或区块头的过程中，也可以执行所述区块中的交易。
所述执行过程，一般可以通过虚拟机执行。以以太坊为例，支持用户在以太坊网络中创建和/或调用一些复杂的逻辑，这是以太坊区别于比特币区块链技术的最大挑战。以太坊作为一个可编程区块链的核心是以太坊虚拟机(EVM，Ethereum Virtual Machine)，每个以太坊节点都可以运行EVM。EVM是一个图灵完备的虚拟机，这意味着可以通过它实现各种复杂的逻辑。用户在以太坊中发布和调用智能合约就是在EVM上运行的。
本实施例中，第一区块链节点可以在可信执行环境(Trusted Execution Environment，TEE)中执行解密的智能合约的代码。例如图4所示，第一区块链节点可以划分为常规执行环境(图中位于左侧)和TEE，客户端提交的交易(如上文所述，交易可以存在其他来源；此处以客户端提交的交易为例进行说明)首先进入常规执行环境中的“交易/查询接口”进行识别，不存在隐私处理需求的交易可以被留在常规执行环境中进行处理(这里可以根据交易发起方的用户类型、交易类型、交易所含的标识符等识别是否存在隐私处理需求)，而将存在隐私处理需求的交易传递至TEE中进行处理。TEE与常规执行环境相互隔离。交易在进入TEE之前处于加密状态，在可信执行环境内则被解密为明文的交易内容，从而在确保数据安全的前提下，使得该明文的交易内容能够在TEE中实现高效处理，并在TEE中生成明文的收据数据。
TEE是基于CPU硬件的安全扩展，且与外部完全隔离的可信执行环境。TEE最早是由Global Platform提出的概念，用于解决移动设备上资源的安全隔离，平行于操作***为应用程序提供可信安全的执行环境。ARM的Trust Zone技术最早实现了真正商用的TEE技术。伴随着互联网的高速发展，安全的需求越来越高，不仅限于移动设备，云端设备，数据中心都对TEE提出了更多的需求。TEE的概念也得到了高速的发展和扩充。现在所说的TEE相比与最初提出的概念已经是更加广义的TEE。例如，服务器芯片厂商Intel，AMD等都先后推出了硬件辅助的TEE并丰富了TEE的概念和特性，在工业界得到了广泛的认可。现在提起的TEE通常更多指这类硬件辅助的TEE技术。 不同于移动端，云端访问需要远程访问，终端用户对硬件平台不可见，因此使用TEE的第一步就是要确认TEE的真实可信。因此现在的TEE技术都引入了远程证明机制，由硬件厂商(主要是CPU厂商)背书并通过数字签名技术确保用户对TEE状态可验证。同时仅仅是安全的资源隔离也无法满足的安全需求，进一步的数据隐私保护也被提出。包括Intel SGX，AMD SEV在内的商用TEE也都提供了内存加密技术，将可信硬件限定在CPU内部，总线和内存的数据均是密文防止恶意用户进行窥探。例如，英特尔的软件保护扩展(SGX)等TEE技术隔离了代码执行、远程证明、安全配置、数据的安全存储以及用于执行代码的可信路径。在TEE中运行的应用程序受到安全保护，几乎不可能被第三方访问。
以Intel SGX技术为例，SGX提供了围圈(enclave，也称为飞地)，即内存中一个加密的可信执行区域，由CPU保护数据不被窃取。以第一区块链节点采用支持SGX的CPU为例，利用新增的处理器指令，在内存中可以分配一部分区域EPC(Enclave Page Cache，围圈页面缓存或飞地页面缓存)，通过CPU内的加密引擎MEE(Memory Encryption Engine)对其中的数据进行加密。EPC中加密的内容只有进入CPU后才会被解密成明文。因此，在SGX中，用户可以不信任操作***、VMM(Virtual Machine Monitor，虚拟机监控器)、甚至BIOS(Basic Input Output System，基本输入输出***)，只需要信任CPU便能确保隐私数据不会泄漏。实际应用中，可以将隐私数据加密后以密文形式传递至围圈中，并通过远程证明将对应的秘钥也传入围圈。然后，在CPU的加密保护下利用数据进行运算，结果会以密文形式返回。这种模式下，既可以利用强大的计算力，又不用担心数据泄漏。
如上文所述，通过在TEE中执行解密后的交易内容，可以确保执行过程在可信环境内完成，以确保隐私信息不会发生泄漏。当上述存在隐私处理需求的交易用于创建智能合约时，该交易中包含智能合约的代码，第一区块链节点可以在TEE中对该交易进行解密得到其所含智能合约的代码，并进而在TEE中执行该代码。当上述存在隐私处理需求的交易用于调用智能合约时，第一区块链节点可以在TEE中执行该代码(若被调用的智能合约处理加密状态，则需要先在TEE中对该智能合约进行解密，以得到相应的代码)。具体的，第一区块链节点可以利用CPU中新增的处理器指令，在内存中分配一部分区域EPC，通过CPU内的加密引擎MEE对上述的明文代码进行加密存入所述EPC中。EPC中加密的内容进入CPU后被解密成明文。在CPU中，对明文的代码进行运算，完成执行过程。例如，在SGX技术中，执行智能合约的明文代码，可以将EVM加载进围圈中。在远程证明过程中，密钥管理服务器可以计算本地EVM代码 的hash值，并与第一区块链节点中加载的EVM代码的hash值比对，比对结果正确作为通过远程证明的一个必要条件，从而完成对第一区块链节点SGX围圈加载的代码的度量。经过度量，正确的EVM可以在SGX中执行上述智能合约的代码。
步骤308，第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储。
在一实施例中，第一区块链节点可以将特殊事件函数产生的日志完全采用明文形式进行存储，即日志所含的所有日志字段均采用明文形式存储。相应的，第一区块链节点可以将收据数据的其余收据内容均以密文形式存储。
在一实施例中，第一区块链节点可以确定特殊事件函数对应的暴露日志字段，而上述的至少一部分收据内容匹配于该特殊事件函数对应的暴露日志字段，使得暴露日志字段对应的收据内容以明文形式存储，而该特殊事件函数的日志中的非暴露日志字段对应的收据内容、普通事件函数的日志对应的所有收据内容仍以密文形式存储，这样可以在保证能够对暴露日志字段实施检索操作的同时，尽可能地实现隐私保护。
在一实施例中，特殊事件函数中包含被标明的暴露日志字段。例如，第一区块链节点可以通过读取特殊事件函数所含的标识符，并将该标识符标明的一个或多个日志字段确定为上述的暴露日志字段。以Solidity语言为例，智能合约包含的特殊事件函数的代码示例如下：
Event buy_candy3(“from”,who,candy_num)；
Event buy_candy4(“to”,who,candy_num)；
在上述代码示例中，智能合约定义了2个事件：事件buy_candy3和事件buy_candy4。
一种情况下，与前述事件buy_candy2_2相类似的，内容“from”、“to”既可以作为类型标识符以表明事件buy_candy3和事件buy_candy4属于特殊事件函数，又能够标明所产生日志中的From字段、To字段需要明文存储。
另一种情况下，内容“from”、“to”仅用于标明From字段、To字段需要明文存储，而需要通过其他方式确定事件buy_candy3和事件buy_candy4是否为特殊事件函数。譬如，虽然事件buy_candy3和事件buy_candy4均为添加上述的类型标识符，但如果这两个事件为前述预先定义的特殊事件函数，比如位于前述的特殊事件函数列表中，那么可以判定事件buy_candy3和事件buy_candy4为特殊事件函数。当然，事件buy_candy3和事件buy_candy4也可以采用前述类型标识符的标注方案，此处并不对此进行限制。 假定事件buy_candy3为特殊事件函数。进一步地，事件buy_candy3中所含的“from”用于标明日志字段From，使得在事件buy_candy3对应生成的日志Logs中，From字段将以明文形式存储，而其余的To字段、Topic字段、Log data字段等以密文形式存储。类似地，假定事件buy_candy4为特殊事件函数。进一步地，事件buy_candy4中所含的“to”用于标明日志字段to，使得在事件buy_candy4对应生成的日志Logs中，To字段将以明文形式存储，而其余的From字段、Topic字段、Log data字段等以密文形式存储。
与暴露日志字段相类似的，特殊事件函数中可以包含被标明的加密日志字段，则暴露日志字段为剩余的其他日志字段。以Solidity语言为例，智能合约包含的特殊事件函数的代码示例如下：
Event buy_candy5(“from”，who,candy_num)；
Event buy_candy6(“to”，who,candy_num)；
在上述代码示例中，智能合约定义了2个事件：事件buy_candy5和事件buy_candy6。
一种情况下，与前述事件buy_candy2_2相类似的，内容“from”、“to”既可以作为类型标识符以表明事件buy_candy5和事件buy_candy6属于特殊事件函数，又能够标明所产生日志中的From字段、To字段需要密文存储。
另一种情况下，内容“from”、“to”仅用于标明所产生日志中的From字段、To字段需要密文存储，而需要通过其他方式确定事件buy_candy5和事件buy_candy6是否为特殊事件函数。譬如，虽然事件buy_candy5和事件buy_candy6均为添加上述的类型标识符，但如果这两个事件为前述预先定义的特殊事件函数，比如位于前述的特殊事件函数列表中，那么可以判定事件buy_candy5和事件buy_candy6为特殊事件函数。当然，事件buy_candy5和事件buy_candy6也可以采用前述类型标识符的标注方案，此处并不对此进行限制。假定事件buy_candy5为特殊事件函数。进一步地，事件buy_candy5中所含的“from”用于标明日志字段From，使得在事件buy_candy5对应生成的日志Logs中，From字段将以密文形式存储，而其余的To字段、Topic字段、Log data字段等为暴露日志字段，均以明文形式存储。类似地，假定事件buy_candy6为特殊事件函数。进一步地，事件buy_candy6中所含的“to”用于标明日志字段to，使得在事件buy_candy6对应生成的日志Logs中，To字段将以密文形式存储，而其余的From字段、Topic字段、Log data字段等为暴露日志字段，均以明文形式存储。
以Solidity语言为例，智能合约包含的特殊事件函数的代码示例如下：
Event buy_candy7 expose_from(who,candy_num)；
Event buy_candy8 show_to(who,candy_num)；
在上述代码示例中，智能合约定义了2个事件：事件buy_candy7和事件buy_candy8。
事件buy_candy7中包含类型标识符“expose”，根据上文所述，可以将该事件buy_candy7判定为特殊事件函数。进一步地，在类型标识符“expose”之后的标识符“_from”用于标明日志字段From，使得在事件buy_candy7对应生成的日志Logs中，From字段将以明文形式存储，而其余的To字段、Topic字段、Log data字段等以密文形式存储。
事件buy_candy8并未包含类型标识符“expose”；但是，可以通过其他方式识别该事件buy_candy8是否为前述的特殊事件函数，比如该事件buy_candy8位于前述的特殊事件函数列表中，那么可以判定该事件buy_candy8为特殊事件函数。进一步地，事件buy_candy8中包含的标识符“show_to”用于标明日志字段to，使得在事件buy_candy8对应生成的日志Logs中，To字段将以明文形式存储，而其余的From字段、Topic字段、Log data字段等以密文形式存储。
类似的，特殊事件函数中可以包含用于标明加密日志字段的标识符，则暴露日志字段为剩余的其他日志字段。以Solidity语言为例，智能合约包含的特殊事件函数的代码示例如下：
Event buy_candy9 expose_hide_from(who,candy_num)；
Event buy_candy10 hide_to(who,candy_num)；
在上述代码示例中，智能合约定义了2个事件：事件buy_candy9和事件buy_candy10。
事件buy_candy9中包含类型标识符“expose”，根据上文所述，可以将该事件buy_candy9判定为特殊事件函数。进一步地，在类型标识符“expose”之后的标识符“hide_from”用于标明日志字段From，使得在事件buy_candy9对应生成的日志Logs中，From字段将以密文形式存储，而其余的To字段、Topic字段、Log data字段等为暴露日志字段，均以明文形式存储。
事件buy_candy10并未包含类型标识符“expose”；但是，可以通过其他方式识别该事件buy_candy10是否为前述的特殊事件函数，比如该事件buy_candy10位于前述的特殊事件函数列表时，可以判定该事件buy_candy10为特殊事件函数。进一步地，事件buy_candy10中的标识符“hide_to”用于标明日志字段to，使得在事件buy_candy10 对应生成的日志Logs中，To字段将以密文形式存储，而其余的From字段、Topic字段、Log data字段等为暴露日志字段，均以明文形式存储。
以太坊支持的高级语言很多，如Solidity、Serpent、LLL语言等，均可以包含上述的用于标明暴露日志字段或加密日志字段的标识符，该标识符在高级语言和字节码形式的智能合约代码中可以相同，或者高级语言的智能合约代码中为第一标识符、字节码形式的智能合约代码中为第二标识符，第一标识符与第二标识符之间可以相互对应。
除了在特殊事件函数中添加上述用于标明暴露日志字段或加密日志字段的标识符，以直接或间接指明相应的暴露日志字段之外，可以预先定义特殊事件函数与暴露日志字段之间的映射关系，或者特殊事件函数与加密日志字段之间的映射关系，使得第一区块链节点可以获取预定义的上述映射关系，并根据智能合约包含的特殊事件函数和上述映射关系，确定该特殊事件函数对应的暴露日志字段。
例如，当映射关系中包含“Event buy_candy11-from_to”、“Event buy_candy12-topic”等内容时，若智能合约中包含事件“Event buy_candy11”，则通过查询到上述的映射关系“Event buy_candy11-from_to”，则可以确定该事件“Event buy_candy11”对应的暴露日志字段为From字段和To字段，若智能合约中包含事件“Event buy_candy12”，则通过查询到上述的映射关系“Event buy_candy12-topic”，则可以确定该事件“Event buy_candy12”对应的暴露日志字段为Topic字段。
可见，在保护用户隐私的前提下，通过对特殊事件函数予以识别，可以根据不同特殊事件函数对于隐私保护程度的差异化需求，使得对应于不同特殊事件函数的日志中，具有差异化的暴露日志字段，从而针对不同特殊事件函数产生的日志实现差异化的加密存储操作，相比于所有收据数据完全以密文形式存储，具有相对更高的灵活性，并且明文存储的收据内容能够直接实现后续的检索等操作，从而满足更加丰富的应用场景，比如驱动诸如DAPP客户端执行相关处理操作等。
在一实施例中，上述的映射关系可以记录于***合约中。如果上述映射关系不存在升级需求，还可以将该映射关系记录于区块链网络的链代码中。
在一实施例中，第一区块链节点读取***合约的代码，所述***合约的代码中定义了与所述特殊事件函数相关的收据数据存储逻辑；相应的，第一区块链节点执行所述***合约的代码，以在所述智能合约包含特殊事件函数时，将对应于所述特殊事件函数的日志中的至少一个收据字段以明文形式存储、将所述收据数据的其余内容以密文形 式存储。
其中，与特殊事件函数相关的收据数据存储逻辑可以包括：对特殊事件函数的识别逻辑、对暴露日志字段的确认逻辑、对暴露日志字段的处理逻辑等。对特殊事件函数的识别逻辑用于指示第一区块链节点识别智能合约所含的特殊事件函数，比如：***合约中可以记录有预定义的特殊事件函数列表，或者***合约中可以记录有基于类型标识符对特殊事件函数进行识别的处理逻辑。对暴露日志字段的确认逻辑用于指示第一区块链节点识别特殊事件函数对应的暴露日志字段，比如：***合约中可以记录有上述的特殊事件函数与暴露日志字段之间的映射关系，或者***合约中可以记录有基于标识符(如前所述的用于标明暴露日志字段或加密日志字段的标识符)对暴露日志字段进行识别的处理逻辑。对暴露日志字段的处理逻辑用于指示第一区块链节点将暴露日志字段对应的收据内容以明文形式存储，而将其余收据内容以密文形式存储。
通过在计算设备(物理机或虚拟机)上运行区块链的程序代码(以下简称为链代码)，可以将该计算设备配置为区块链网络中的区块链节点，比如上述的第一区块链节点等。换言之，第一区块链节点通过运行上述的链代码，以实现相应的功能逻辑。因此，可以在创建区块链网络时，将上文所述的与特殊事件函数相关的收据数据存储逻辑写入链代码中，使得各个区块链节点均可以实现该收据数据存储逻辑；以第一区块链节点为例，该收据数据存储逻辑即上文所述的：收据数据存储逻辑中可以具体定义了每一交易类型对应的暴露字段，使得第一区块链节点可以根据交易类型，确定交易产生的收据数据中哪些收据内容需要明文存储、哪些收据内容需要密文存储。
然而，链代码的升级更新相对较为困难，使得采用链代码实现对收据数据的存储存在灵活性低、可扩展性不足的问题。为了实现对链代码的功能扩展，如图5所示，可以采用链代码与***合约相结合的方式：链代码用于实现区块链网络的基础功能，而运行过程中的功能扩展可以通过***合约的方式实现。与上述的智能合约相类似的，***合约包括譬如字节码形式的代码，第一区块链节点可以通过运行***合约的代码(比如，根据唯一对应的地址“0x53a98…”来读取该***合约中的代码)，实现对链代码的功能补充。
区别于上述由用户发布至区块链的智能合约，***合约无法由用户自由发布。第一区块链节点读取的***合约可以包括配置于区块链网络的创世块中的预置***合约；以及，区块链网络中的管理员(即上述的管理用户)可以具有针对***合约的更新权限，从而针对诸如上述的预置***合约进行更新，则上述第一区块链节点读取的*** 合约还可以包括相应的更新后***合约。当然，更新后***合约可以由管理员对预置***合约实施一次更新后得到；或者，更新后***合约可以由管理员对预置***合约实施多次迭代更新后得到，比如由预置***合约更新得到***合约1、对***合约1更新得到***合约2、对***合约2更新得到***合约3，该***合约1、***合约2、***合约3均可以视为更新后***合约，但第一区块链节点通常会以最新版本的***合约为准，比如第一区块链节点会以***合约3中的代码为准，而非***合约1或***合约2中的代码。
除了创世块中包含的预置***合约之外，管理员还可以在后续区块内发布***合约，以及针对所发布的***合约进行更新。总之，应当通过诸如权限管理等方式，对***合约的发布和更新实施一定程度的限制，以确保区块链网络的功能逻辑能够正常运作，并且避免对任何用户造成不必要的损失。
因此，第一区块链节点可以读取***合约的代码，该***合约的代码中定义了与特殊事件函数相关的收据数据存储逻辑；然后，第一区块链节点可以执行该***合约的代码，以针对智能合约所含的特殊事件函数对应的至少一部分收据内容(如暴露日志字段对应的收据内容)以明文形式存储、其余收据内容以密文形式存储。
在一实施例中，第一区块链节点通过密钥对特殊事件函数中的非暴露日志字段以及非特殊事件函数对应的收据内容进行加密。所述加密，可以采用对称加密，也可以采用非对称加密。如果第一区块链节点用对称加密方式，即用对称加密算法的对称密钥对收据内容加密，则客户端(或其他持有密钥的对象)可以用该对称加密算法的对称密钥对加密后的收据内容进行解密。
在一实施例中，第一区块链节点用对称加密算法的对称密钥对收据内容进行加密时，该对称密钥可由客户端预先提供至第一区块链节点。那么，由于只有客户端(实际应当为客户端上的已登录账户对应的用户)和第一区块链节点掌握该对称密钥，使得仅该客户端能够解密相应的加密后的收据内容，避免无关用户甚至不法分子对加密后的收据内容进行解密。
例如，客户端在向第一区块链节点发起交易时，客户端可以用对称加密算法的初始密钥对交易内容进行加密，以得到该交易；相应地，第一区块链节点可以通过获得该初始密钥，以用于直接或间接对收据内容进行加密。譬如，该初始密钥可以由客户端与第一区块链节点预先协商得到，或者由密钥管理服务器发送至客户端和第一区块链节点，或者由客户端发送至第一区块链节点。当初始密钥由客户端发送至第一区块链节点 时，客户端可以通过非对称加密算法的公钥对该初始密钥进行加密后，将加密后的初始密钥发送至第一区块链节点，而第一区块链节点通过非对称加密算法的私钥对该加密后的初始密钥进行解密，得到初始密钥，即上文所述的数字信封加密，此处不再赘述。
在一实施例中，第一区块链节点可以采用上述的初始密钥对收据内容进行加密。不同交易采用的初始密钥可以相同，使得同一用户所提交的所有交易均采用该初始密钥进行加密，或者不同交易采用的初始密钥可以不同，比如客户端可以针对每一交易随机生成一初始密钥，以提升安全性。
在一实施例中，第一区块链节点可以根据初始密钥与影响因子生成衍生密钥，并通过该衍生密钥对收据内容进行加密。相比于直接采用初始密钥进行加密，衍生密钥可以增加随机度，从而提升被攻破的难度，有助于优化数据的安全保护。影响因子可以与交易相关；例如，影响因子可以包括交易哈希值的指定位，比如第一区块链节点可以将初始密钥与交易哈希值的前16位(或前32位、后16位、后32位，或者其他位)进行拼接，并对拼接后的字符串进行哈希运算，从而生成衍生密钥。
在一实施例中，第一区块链节点还可以采用非对称加密方式，即用非对称加密算法的公钥对收据内容加密，则相应地，客户端可以用所述非对称加密算法的私钥解密上述加密后的收据内容。非对称加密算法的密钥，例如可以是由客户端生成一对公钥和私钥，并将公钥预先发送至第一区块链节点，从而第一区块链节点可以将收据内容用该公钥加密。
第一区块链节点通过运行用于实现某一功能的代码，以实现该功能。因此，对于需要在TEE中实现的功能，同样需要执行相关代码。而对于在TEE中执行的代码，需要符合TEE的相关规范和要求；相应地，对于相关技术中用于实现某一功能的代码，需要结合TEE的规范和要求重新进行代码编写，不仅存在相对更大的开发量，而且容易在重新编写过程中产生漏洞(bug)，影响功能实现的可靠性和稳定性。
因此，第一区块链节点可以通过在TEE之外执行存储功能代码，将TEE中生成的收据数据(包括需要明文存储的明文形式的收据内容，以及需要密文存储的密文形式的收据内容)存储至TEE之外的外部存储空间，使得该存储功能代码可以为相关技术中用于实现存储功能的代码、不需要结合TEE的规范和要求重新进行代码编写，即可针对收据数据实现安全可靠的存储，不仅可以在不影响安全、可靠程度的基础上，减少相关代码的开发量，而且可以通过减少TEE的相关代码而降低TCB(Trusted Computing Base，可信计算基)，使得TEE技术与区块链技术进行结合的过程中，额外造成的安全 风险处于可控范围。
在一实施例中，第一区块链节点可以在TEE内执行写缓存功能代码，以将上述的收据数据存入TEE内的写缓存中，比如该写缓存可以对应于如图1所示的“缓存”。进一步的，第一区块链节点将写缓存中的数据从可信执行环境输出，以存储至外部存储空间。其中，写缓存功能代码可以以明文形式存储于TEE中，可以直接在TEE中执行该明文形式的缓存功能代码；或，写缓存功能代码可以以密文形式存储于TEE之外，比如存储于上述的外部存储空间(比如图4所示的“打包+存储”，其中“打包”表示第一区块链节点在可信执行环境之外对交易进行打包成块)，可以将该密文形式的写缓存功能代码读入TEE、在TEE中进行解密为明文代码，并执行该明文代码。
写缓存是指在将数据写入外部存储空间时，为了避免造成对外部存储空间的“冲击”而提供的“缓冲”机制。例如，可以采用buffer实现上述的写缓存；当然，写缓存也可以采用cache来实现，本说明书并不对此进行限制。实际上，由于TEE为隔离的安全环境，而外部存储空间位于TEE之外，使得通过采用写缓存机制，可以对缓存内的数据进行批量写入外部存储空间，从而减少TEE与外部存储空间之间的交互次数，提升数据存储效率。同时，TEE在不断执行各条交易的过程中，可能需要调取已生成的数据，如果需调用的数据恰好位于写缓存中，可以直接从写缓存中读取该数据，这样一方面可以减少与外部存储空间之间的交互，另一方面免去了对从外部存储空间所读取数据的解密过程，从而提升在TEE中的数据处理效率。
当然，也可以将写缓存建立于TEE之外，比如第一区块链节点可以在TEE之外执行写缓存功能代码，从而将上述的收据数据存入TEE外的写缓存中，并进一步将写缓存中的数据存储至外部存储空间。
在图3所示实施例的基础上，本说明书可以进一步识别交易对应的智能合约的代码所含的暴露标识符，从而同时根据智能合约所含的特殊事件函数和暴露标识符标明的对象，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储，所述至少一部分收据内容匹配于所述暴露标识符标明的对象。
暴露标识符为智能合约的编程语言中所定义的全局性标识，适用于采用该编程语言编写的所有智能合约。因此，通过在编程语言中定义暴露标识符，使得在任一智能合约的代码使用该暴露标识符，即可实现对收据数据的存储控制。例如，用户在编写智 能合约的代码时，可以通过在代码中添加暴露标识符来标明一个或多个对象，以表明用户希望收据数据中对应于这部分对象的收据内容采用明文存储，而剩余未标注暴露标识符的对象所对应的收据内容不允许采用明文存储、必须采用密文存储，以实现相应的隐私保护。
换言之，对于暴露标识符标明的对象，从编程语言的维度上而言，允许将相应的收据内容以明文形式存储；但是，本说明书还可以进一步考量智能合约所含的事件函数，并从编程语言和事件函数的维度上实现综合考量，确定是否将暴露标识符标明的对象所对应的收据内容以明文形式存储。与事件函数相关的信息将在下文描述，此处暂不赘述。
如上文所述，在用于创建智能合约的交易中，data字段保存的可以是该智能合约的字节码。字节码由一连串的字节组成，每一字节可以标识一个操作。基于开发效率、可读性等多方面考虑，开发者可以不直接书写字节码，而是选择一门高级语言编写智能合约代码。高级语言编写的智能合约的代码，经过编译器编译而生成字节码，进而该字节码可以部署到区块链上。以太坊支持的高级语言很多，如Solidity、Serpent、LLL语言等。
以Solidity语言为例，用其编写的合约与面向对象编程语言中的类(Class)很相似，在一个合约中可以声明多种成员，包括状态变量、函数、函数修改器、事件等。如下是以Solidity语言编写的一个简单的智能合约的代码示例1：
Figure PCTCN2020089385-appb-000001
在基于Solidity语言编写的智能合约的代码中，可以通过暴露标识符来标明一个或多个对象，使得收据数据中对应于这部分对象的收据内容被允许以明文形式存储(需要进一步结合事件函数的维度来确定实际是否采用明文存储)，而其余的收据内容应当 以密文形式存储。类似地，在基于Serpent、LLL语言等编写的智能合约的代码中，同样可以通过暴露标识符来标明一个或多个对象，以实现相关收据内容的明文存储。
暴露标识符可以为专用于标明允许明文存储的收据字段，例如可以采用关键字plain来表征该暴露标识符。那么，对于希望以明文形式存储的收据内容，可以在相应的对象之前添加plain(或者，也可以采用其他方式与相应的对象进行关联)。
暴露标识符标明的对象可以包括收据字段，比如上文所述的Result字段、Gas used字段、Logs字段、Output字段等，或者Logs字段中进一步包含的From字段、To字段、Topic字段、Log data字段等。例如，可以将上述的代码示例1调整为下述的代码示例2：
Figure PCTCN2020089385-appb-000002
在上述的代码示例2中，通过在智能合约的代码最前方添加暴露标识符plain，使得智能合约的代码被执行后，产生的收据数据中的所有字段均允许以明文形式进行存储。
当然，在其他实施例中，也可以具体指明需要明文存储的字段。比如，通过暴露标识符对From字段进行标注时，可使得智能合约的代码被执行后，产生的收据数据中的From字段对应的收据内容允许以明文形式进行存储，那么后续可以针对该From字段中的收据内容实施检索操作，比如可以统计某一账户所发起的交易量等。
除了收据字段之外，暴露标识符还可以用于标明其他对象。例如，暴露标识符标明的对象可以包括状态变量。以状态变量“price”为例，可以将上述的代码示例1调整为下述的代码示例3：
Figure PCTCN2020089385-appb-000003
Figure PCTCN2020089385-appb-000004
在上述的代码示例3中，通过在状态变量“price”的类型int之前添加暴露标识符“plain”(或者，可以将暴露标识符plain置于类型int之后)，使得智能合约的代码被执行后，在产生的收据数据的各个字段(通常包括Topic字段、Output字段等)中，与状态变量“price”相关的收据内容允许以明文形式进行存储，那么后续可以针对与状态变量“price”相关的收据内容实施检索操作。
在一实施例中，第一区块链节点接收的交易对应的智能合约，可以是通过高级语言编写的智能合约，或者可以是字节码形式的智能合约。其中，当智能合约为高级语言编写的智能合约时，第一区块链节点还通过编译器对该高级语言编写的智能合约进行编译，生成字节码形式的智能合约，以在可信执行环境中执行。而当第一区块链节点接收的交易对应的智能合约为字节码形式的智能合约时，该字节码形式的智能合约可由客户端通过编译器对高级语言编写的智能合约进行编译而得到，而该高级语言编写的智能合约由用户在客户端上编写得到。
对于第一区块链节点接收的交易对应的智能合约，可以为用户在第一区块链节点上生成的智能合约。当用户采用高级语言编写得到上述的智能合约时，第一区块链节点还通过编译器将该高级语言编写的智能合约编译为字节码形式的智能合约；或者，用户也可能在第一区块链节点上直接编写得到字节码形式的智能合约。
对于第一区块链节点接收的交易对应的智能合约，可以为用户在客户端上生成的智能合约。例如，用户通过对应的账户在客户端生成该交易后，通过该客户端将交易提交至第一区块链节点。以图4为例，第一区块链节点中包含交易/查询接口，该接口可与客户端对接，使得客户端可以向第一区块链节点提交上述交易。比如上文所述，用户可以采用高级语言在客户端上编写智能合约，然后由客户端通过编译器对该高级语言的智能合约进行编译，得到相应的字节码形式的智能合约。当然，客户端可以直接将高级 语言编写的智能合约发送至第一区块链节点，使得第一区块链节点通过编译器编译为字节码形式的智能合约。
对于第一区块链节点接收的交易对应的智能合约，可以为客户端通过第二区块链节点发来的交易中的智能合约，该智能合约通常为字节码形式；当然，该智能合约也可以为高级语言编写的智能合约，则第一区块链节点可以通过编译器编译为字节码形式的智能合约。
在一实施例中，当智能合约的代码中包括暴露标识符时，高级语言编写的智能合约与字节码形式的智能合约可以具有相同的暴露标识符。而本领域技术人员应当理解的是：字节码可以采用不同于高级语言的暴露标识符，比如高级语言编写的智能合约的代码中包含第一标识符、字节码形式的智能合约的代码中包含第二标识符，则第一标识符与第二标识符之间存在对应关系，确保由高级语言编译为字节码后，不会影响暴露标识符的功能。
在智能合约的代码中，暴露标识符可以标明一个或多个对象，这些对象在收据数据中存在对应的收据内容。而特殊事件函数被执行后，收据数据中包含对应于特殊事件函数的日志，该日志实际为收据数据中的部分收据内容。而本说明书中通过对暴露标识符和特殊事件函数进行综合考量，可以筛选出上述两部分收据内容的交叉内容，并针对该交叉内容实施明文存储，收据数据的其余内容均采用密文存储。
由于暴露标识符为智能合约的编程语言中所定义的全局性标识，因而只要在智能合约中写入暴露标识符后，就难以修改该暴露标识符所标明的对象。而特殊事件函数的定义并不一定基于编程语言实现，比如在基于特殊事件函数列表等方式记录特殊事件函数时，即便智能合约中包含的某一事件函数原本属于特殊事件函数，也可以通过对特殊事件函数列表进行更改的方式，将原有的特殊事件函数更新为普通事件函数，从而避免该事件函数产生的日志以明文形式存储，或者将原有的普通事件函数更新为特殊事件函数，使得该事件函数产生的日志中的至少一部分内容以明文形式存储。
以上述的代码示例2为例：假定事件currentPrice原本并未记录于特殊事件函数列表中，即事件currentPrice对应于普通事件函数，那么即便在智能合约的代码中添加了暴露标识符plain，事件currentPrice产生的日志中的各个字段仍以密文形式存储。但是，如果将事件currentPrice添加至特殊事件函数列表中，那么代码示例2不需要调整的情况下，即可使得事件currentPrice对应的日志中的各个字段以明文形式存储。
以上述的代码示例3为例：假定事件currentPrice原本并未记录于特殊事件函数列表中，即事件currentPrice对应于普通事件函数，那么即便在智能合约的代码中添加了暴露标识符plain，在事件currentPrice产生的日志中，状态变量price的取值仍以密文形式存储。但是，如果将事件currentPrice添加至特殊事件函数列表中，那么代码示例3不需要调整的情况下，即可使得事件currentPrice对应的日志中，状态变量price的取值以明文形式存储。
需要指出的是：在上述的代码示例2中，通过在代码最前方声明“plain”，该暴露标识符“plain”所标明的对象为收据数据中的所有字段，且这些字段均为合约级对象，使得第一区块链节点在存储收据数据时，收据数据中所有对应于该合约级对象的收据内容，均被允许以明文形式存储。当然，如果代码示例2中通过暴露标识符标注了From字段，那么该From字段为上述的合约级对象，使得第一区块链节点在存储收据数据时，收据数据中所有对应于该From字段的收据内容，均被允许以明文形式存储。类似地，在上述的代码示例3中，暴露标识符“plain”所标明的状态变量“price”同样为合约级对象，使得第一区块链节点在存储收据数据时，收据数据中所有对应于该合约级对象“price”的收据内容，均被允许以明文形式存储。
尤其是，当智能合约的代码中包含多个事件函数时，在多个事件函数分别产生的各自对应的Logs字段中，均可能存在合约级对象所对应的收据内容；进一步地，可以通过识别各个事件函数的类型为普通事件函数或特殊事件函数，从而将所有特殊事件函数所产生的日志中对应于合约级对象的收据内容以明文形式存储。例如，智能合约可以包括下述的代码示例4：
plain Contract Example{
int price；
int price1；
event currentPrice1(int price)；
event currentPrice2(int price1)；
…
在上述的代码示例4中，与代码示例2相类似地，暴露标识符“plain”位于智能合约的代码最前方，使得收据数据中的所有字段均被标注为合约级对象；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：假定事件currentPrice1对应于特 殊事件函数列表中定义的特殊事件函数、事件currentPrice2对应于普通事件函数，那么在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1包含的所有字段均以明文形式存储、日志Log2包含的所有字段均以密文形式存储。并且，如果通过对特殊事件函数列表进行更新后，将事件currentPrice2更新为对应于特殊事件函数，那么日志Log2包含的所有字段将均以明文形式存储，而无需对智能合约的代码做任何变动。当然，如果代码示例4中通过暴露标识符标注了From字段，那么该From字段为上述的合约级对象，使得事件currentPrice1为特殊事件函数、事件currentPrice2为普通事件函数时，日志Log1中的From字段以明文形式存储、其余字段以密文形式存储，而日志Log2包含的所有字段均以密文形式存储；以及，当事件currentPrice2更新为特殊事件函数，那么日志Log2中的From字段以明文形式存储、其余字段以密文形式存储。
对于上述的合约级对象而言，可以通过前述的类型标识符来标明智能合约所含的事件函数是否为特殊事件函数。例如，可以将上述的代码示例4调整为下述的代码示例5：
plain Contract Example{
int price；
int price1；
event currentPrice1expose(int price)；
event currentPrice2(int price1)；
…
在上述的代码示例5中，与代码示例2相类似地，合约级对象包括收据数据中的所有字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：由于事件currentPrice1在包含如前所述的类型标识符expose，使得该事件currentPrice1被标注为对应于特殊事件函数，而事件currentPrice2并未包含类型标识符expose，使得事件currentPrice2被标注为对应于普通事件函数，那么在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1包含的所有字段以明文形式存储、日志Log2包含的所有字段以密文形式存储。
虽然类型标识符与暴露标识符相类似的，都是智能合约的编程语言中所定义的全局性标识，但是暴露标识符作用于合约级对象、类型标识符作用于事件函数，使得通 过将暴露标识符与类型标识符配合使用，仅需单次添加暴露标识符即可设定形成上述的合约级对象，并且进而可以灵活地标注希望对合约级对象进行明文存储的事件函数，尤其是当智能合约中包含的事件函数的数量较多、事件函数中涉及的对象(如字段或状态变量)的数量较多时，无需针对每一事件函数所涉及的每一对象分别实施设定操作，可以简化代码逻辑、防止错标或漏标。
上述实施例中的合约级对象包括字段，比如From字段等。合约级对象还可以包括状态变量；例如，可以将上述的代码示例4调整为下述的代码示例6：
Contract Example{
plain int price；
int price1；
event currentPrice1(int price)；
event currentPrice2(int price)；
event currentPrice3(int price1)；
…
在上述的代码示例6中，事件currentPrice1和事件currentPrice2引用了状态变量price、事件currentPrice3引用了状态变量price1；由于在状态变量price的类型int之前添加了暴露标识符“plain”，可以将该状态变量price作为上述的合约级对象。相应的，对于引用该合约级对象的事件函数，在特殊事件函数所产生的日志中，该合约级对象对应的收据内容以明文形式存储，而普通事件函数即便引用了该合约级对象，所产生的日志仍以密文形式存储。例如，结合区块链网络中记录的特殊事件函数列表：当事件currentPrice1对应于特殊事件函数时，由于事件currentPrice1引用了作为合约级对象的状态变量price，因而在该事件currentPrice1产生的日志Logs中，与状态变量price相关的收据内容均以明文形式进行存储；当事件currentPrice2对应于普通事件函数时，虽然事件currentPrice2引用了作为合约级对象的状态变量price，但在该事件currentPrice2产生的日志Logs中，与状态变量price相关的收据内容均以密文形式进行存储；虽然事件currentPrice3对应于特殊事件函数，但是由于事件currentPrice3并未引用作为合约级对象的状态变量price，因而事件currentPrice3产生的日志Logs均以密文形式进行存储。
与前述实施例相类似的，对于状态变量类型的合约级对象，可以通过类型标识符来标注事件函数的类型。例如，可以将上述的代码示例6调整为下述的代码示例7：
Contract Example{
plain int price；
int price1；
event currentPrice1 expose(int price)；
event currentPrice2(int price)；
event currentPrice3 expose(int price1)；
…
在上述的代码实例7中，通过暴露标识符可以将状态变量price标注为合约级对象，而状态变量price1并非合约级对象；通过类型标识符expose标明的事件currentPrice1、事件currentPrice3均对应于特殊事件函数，而事件currentPrice2对应于普通事件函数。因此，在该事件currentPrice1产生的日志Logs中，与状态变量price相关的收据内容均以明文形式进行存储；在该事件currentPrice2产生的日志Logs中，与状态变量price相关的收据内容均以密文形式进行存储；事件currentPrice3产生的日志Logs均以密文形式进行存储。
除了合约级对象之外，暴露标识符标明的对象可以包括：对应于智能合约中定义的至少一个事件的事件级对象，使得第一区块链节点在存储收据数据时，将特殊事件函数产生的收据内容中对应于该事件级对象的部分以明文形式存储。尤其是，当智能合约中包含多个事件时，可以针对至少一部分事件设定上述的事件级对象，使得这部分事件产生的收据内容中对应于该事件级对象的部分以明文形式存储，而这部分事件产生的其他收据内容和其余事件产生的所有收据内容均以密文形式存储。以From字段为例，可以将上述的代码示例5调整为下述的代码示例8：
Contract Example{
int price；
int price1；
event currentPrice1(“from”,int price)；
event currentPrice2(int price1)；
…
在上述的代码示例8中，事件currentPrice1虽然未添加暴露标识符“plain”，但是包含了内容“from”，该内容“from”对应于From字段，用于表明事件currentPrice1 所产生日志中的From字段需要以明文形式存储，因而该内容“from”既属于上述的暴露标识符，又标明了需要明文存储的From字段。并且，由于内容“from”位于事件currentPrice1中，因而From字段为事件级对象，使得当该事件currentPrice1对应于特殊事件函数时，在该事件currentPrice1对应产生的日志Logs中，From字段将以明文形式进行存储、其他字段以密文形式存储。而对于代码示例8所含的另一事件currentPrice2，由于并未针对该事件currentPrice2添加暴露标识符，因而不论该事件currentPrice2对应于特殊事件函数或普通事件函数，所产生的日志Logs均以密文形式存储。
上述的关键词“from”指明了将From字段设定为事件级对象；对于事件级对象为字段类型的情况，也可以并不指明具体的字段。例如，可以将上述的代码示例5调整为下述的代码示例9：
Contract Example{
int price；
int price1；
plain event currentPrice1(int price,int price1)；
event currentPrice2(int price1)；
…
在上述的代码示例9中，通过在事件currentPrice1之前添加暴露标识符“plain”，可以将该事件currentPrice1所产生的日志中的所有字段均作为上述的事件级对象，譬如前述的From字段、To字段、Topic字段、Log Data字段等。那么，当该事件currentPrice1对应于特殊事件函数时，相当于将该事件currentPrice1对应的所有收据内容(比如产生的日志)均以明文形式存储。
事件级对象还可以包括状态变量。从状态变量的维度而言，上述的代码示例9可以解释为：事件currentPrice1引用了状态变量price和price1、事件currentPrice2引用了状态变量price1；由于通过在事件currentPrice1之前添加暴露标识符“plain”，可以将该事件currentPrice1所引用的状态变量price和price1作为上述的事件级对象，使得当该事件currentPrice1对应于特殊事件函数时，在该事件currentPrice1产生的日志Logs中，与状态变量price和price1相关的收据内容均以明文形式进行存储。而对于代码示例9所含的另一事件currentPrice2，由于并未针对该事件currentPrice2添加暴露标识符，因而不论该事件currentPrice2对应于特殊事件函数或普通事件函数，在该事件 currentPrice2所产生的日志Logs中，与状态变量price1相关的收据内容均以密文形式存储。
当事件级对象包括状态变量时，还可以具体指示为事件所引用的一个或多个状态变量。例如，可以将上述的代码示例5调整为下述的代码示例10：
Contract Example{
int price；
int price1
event currentPrice1(plain int price，int price1)；
event currentPrice2(int price)；
…
在上述的代码示例10中，在事件currentPrice1对应的事件函数中，包含添加在状态变量price的类型int之前的暴露标识符plain，使得该状态变量price被配置为事件级对象，该事件级对象仅适用于该事件currentPrice1。由于暴露标识符plain位于事件currentPrice1对应的事件函数中，而事件currentPrice2对应的事件函数虽然引用了状态变量price但是并未标注暴露标识符plain，因而事件currentPrice2对应的事件函数与事件级对象无关。因此，即便事件currentPrice1和事件currentPrice2均对应于特殊事件函数，也只有在事件currentPrice1产生的日志中，将作为事件级对象的状态变量price对应的收据内容以明文形式存储，而事件currentPrice2产生的日志均以密文形式存储。类似地，虽然事件currentPrice1引用了状态变量price1，但是由于该状态变量price1并未被暴露标识符进行标注，因而该状态变量price1并不属于事件级对象，即便事件currentPrice1对应于特殊事件函数，但在事件currentPrice1产生的日志中，该状态变量price1对应的收据内容仍以密文形式存储。
需要指出的是：在上述的代码示例8～10对应的实施例中，即对于事件级对象而言，可以通过特殊事件函数列表或者类型标识符的方式识别智能合约所含的事件函数是否为特殊事件函数，此处不再一一赘述。
本说明书通过在一定程度上暴露收据内容，以用于实现对DAPP客户端的驱动或其他的功能扩展。并且，本说明书通过综合考虑暴露标识符标明的对象和特殊事件函数产生的日志，可以准确选取用于明文存储的收据内容，即同时满足“匹配于暴露标识符标明的对象”和“属于特殊事件函数产生的日志”的收据内容，从而在满足上述功能 扩展需求的同时，确保绝大部分的用户隐私能够得到保护。尤其是，当第一区块链节点是根据区块链网络上记载的信息(如特殊事件函数列表)来识别特殊事件函数时，可以在智能合约已经创建之后，通过对“特殊事件函数”进行更新，以调整收据数据的存储方式，比如将原本明文存储的收据内容改为密文存储，或者将原本密文存储的收据内容改为明文存储。
在图3所示实施例的基础上，本说明书可以进一步识别交易发起方的用户类型，从而同时根据智能合约所含的特殊事件函数和交易发起方的用户类型，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，当交易发起方属于预设用户类型时，对应于所述特殊事件函数的日志中的至少一个日志字段以明文形式存储、所述收据数据的其余内容以密文形式存储，当交易发起方不属于所述预设用户类型时，所述收据数据以密文形式存储。
在一实施例中，用户在区块链上存在对应的外部账户，并基于该外部账户在区块链上发起交易或执行其他操作。例如，当用户在区块链上发起一笔交易时，实际上是通过该用户对应的外部账户发起这笔交易，因而该交易对应的交易发起方可以认为是该用户，也可以认为是该用户对应的外部账户。
在一实施例中，用户存在多种类型。每一用户类型存在对应的隐私保护需求。可以根据隐私保护需求的差异，将用户分为相应的多种类型；或者，首先根据某一因素划分形成多种用户类型，然后为每一用户类型配置对应的隐私保护需求。总之，在用户类型与隐私保护需求之间可以建立起对应关系，使得第一区块链节点可以基于交易发起方的用户类型，确定是否需要针对特殊事件函数对应的日志实施明文存储。
在一实施例中，交易发起方所属的用户类型，即相应的外部账户所属的用户类型。因此，第一区块链节点可以确定交易发起方对应的外部账户，并通过查询区块链上记录的外部账户对应的用户类型，以作为交易发起方所属的用户类型。对于外部账户对应的用户类型，可以通过多种形式记录于区块链上：
例如，外部账户可以包括记录于区块链上的用户类型字段(如UserType字段)，该用户类型字段的取值对应于用户类型。比如，当用户类型字段的取值为00时，用户类型为普通用户，当用户类型字段的取值为01时，用户类型为高级用户，当用户类型字段的取值为11时，用户类型为管理用户等。因此，第一区块链节点可以通过读取上述的外部账户的用户类型字段，即可基于取值确定相应的用户类型。
再例如，在创建上述的外部账户时，用户类型可以被配置为关联至该外部账户，并且用户类型与外部账户之间的关联关系可以被记录于区块链中，比如该关联关系可以包括用户类型与外部账户的账户地址。在该实施例中，外部账户的数据结构并不需要改变，即外部账户无需包含上述的用户类型字段。因此，第一区块链节点可以通过读取区块链上记录的关联关系，并基于交易发起方对应的外部账户，确定该外部账户对应的用户类型。其中，用户类型与外部账户之间的关联关系可以被记录于***合约或链代码中，尤其是当外部账户为区块链网络的预置账户时，在创建***合约或编写链代码的过程中，即可获知该外部账户并将对应的关联关系添加至***合约或链代码中；或者，当外部账户并非预置账户时，可以在后续创建外部账户时，通过对***合约或链代码进行更新，将该外部账户对应的关联关系添加至***合约或链代码中。
在一实施例中，可以在一定条件下对外部账户的用户类型进行修改。例如，管理用户可以具备修改权项，使得第一区块链节点可以根据管理用户发起的更改请求，更改上述外部账户对应的用户类型。管理用户可以对应于创世块中预置的、具有管理权限的外部账户，使得管理用户可以对其他的普通用户、高级用户等进行类型更改，比如将普通用户更改为高级用户、将高级用户更改为普通用户等。
在一实施例中，在保护用户隐私的前提下，通过对用户类型予以识别，可以根据不同用户对于隐私保护程度的差异化需求，针对特殊事件函数对应的日志实施差异化的存储操作，具有较高的灵活性。例如，普通用户的隐私保护的需求相对更低、对基于收据数据的触发操作需求相对更高，那么对于普通用户发起的交易所产生的收据数据，可以将特殊事件函数对应的日志相对更多地采用明文形式存储，以便针对明文存储的收据内容实施检索并触发相对更多类型的关联操作。再例如，高级用户的隐私保护的需求相对更高、对基于收据数据的触发操作需求相对更低，那么对于高级用户发起的交易所产生的收据数据，可以将特殊事件函数对应的日志相对更少地采用明文形式存储、相对更多的收据内容采用密文形式存储，甚至可以完全以密文形式存储，以满足其隐私需求。
总之，当交易发起方用户属于预设用户类型时，第一区块链节点可以将特殊事件函数产生的日志完全采用明文形式进行存储，即日志所含的所有日志字段均采用明文形式存储。相应的，第一区块链节点可以将收据数据的其余收据内容均以密文形式存储。以及，当交易发起方用户属于预设用户类型时，第一区块链节点可以确定特殊事件函数对应的暴露日志字段，并将该暴露日志字段以明文形式存储、其余的非暴露日志字段仍以密文形式存储，这样可以在保证能够对暴露日志字段实施检索操作的同时，尽可能地 实现隐私保护。
在图3所示实施例的基础上，本说明书可以进一步识别交易类型对应的暴露字段，从而同时根据智能合约所含的特殊事件函数和交易类型对应的暴露字段，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的暴露字段以明文形式存储、所述收据数据的其余内容以密文形式存储。
在一实施例中，交易可以包括交易类型字段(如TransType字段)，该交易类型字段的取值用于标明相应的交易类型。因此，通过读取交易所含交易类型字段的取值，可以确定出交易类型，比如存证类型、资产转移(如转账)类型、合约创建类型、合约调用类型等，本说明书并不对此进行限制。
在一实施例中，不同类型的交易可以分别存在对应的暴露字段。暴露字段为收据数据中指定的一个或多个字段，在收据数据需要密文存储以保护隐私的前提下，可以结合智能合约所含的特殊事件函数，选择性地将特殊事件函数对应的日志中的暴露字段以明文形式进行存储，以便后续针对该明文形式存储的收据内容实施检索等操作。
在一实施例中，可以预先定义每一交易类型与暴露字段之间的映射关系，并将该映射关系记录于区块链中，使得第一区块链节点可以获取该预定义的映射关系，并进一步根据上述交易的交易类型和该映射关系，确定收据数据中的暴露字段。例如，存证类型对应的暴露字段可以包括上述From字段之外的所有字段，资产转移类型对应的暴露字段可以包括上述的To字段，合约创建类型和合约调用类型对应的暴露字段可以包括上述From字段之外的所有字段，而对于其他交易类型的情况，此处不再一一赘述。
其中，上述的映射关系具体可以记录于***合约中。还可以将该映射关系记录于区块链网络的链代码中。通过将映射关系记录于***合约中，便于后续针对该映射关系进行更新升级，而记录于链代码中的映射关系则相对不易实现更新升级，后续将针对两者的差异进行描述，此处暂不赘述。
在保护用户隐私的前提下，通过对交易类型予以识别，可以根据不同类型的交易对于隐私保护的差异化需求，确定出可以明文存储的暴露字段，并进一步根据交易调用的智能合约所含的事件函数，在存储过程中体现出不同类型的事件函数对于隐私保护的差异化需求，具有较高的灵活性。例如，特殊事件函数涉及的暴露字段以明文形式存储，而特殊事件函数涉及的非暴露字段、普通事件函数所涉及的所有收据字段等，均以 密文形式存储。
在图3所示实施例的基础上，本说明书可以进一步识别收据数据中满足预设条件的收据内容，从而同时根据智能合约所含的特殊事件函数和收据内容对预设条件的满足情况，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中满足预设条件的至少一个日志字段以明文形式存储、所述收据数据的其余内容以密文形式存储。
在一实施例中，针对收据数据中对应于特殊事件函数的日志，可将该日志的所有日志字段均与相应的预设条件进行比较，并将所有满足预设条件的日志字段以明文形式存储。相应的，对于对应于特殊事件函数但为满足预设条件的日志字段、对应于普通事件函数的日志、收据数据中的其他收据内容等，均以密文形式存储。
在一实施例中，针对收据数据中对应于特殊事件函数的日志，可以确定出该特殊事件函数对应的暴露日志字段，并将暴露日志字段与相应的预设条件进行比较，从而将满足预设条件的暴露日志字段以明文形式存储。暴露日志字段往往涉及到的隐私内容相对较少，或者不涉及到核心隐私内容，以明文形式存储的风险相对较低；而非暴露日志字段可能涉及到相对更多或相对更重要的隐私内容，以密文形式存储可以确保不偏离隐私保护的核心目的。而通过结合预设条件进行判断，可以进一步筛除暴露日志字段可能包含的不适宜公开的隐私内容，从而在保证能够完成检索操作的同时，尽可能地实现隐私保护。
在一实施例中，在保护用户隐私的前提下，通过对智能合约所含的事件函数予以识别，可以根据不同类型的事件函数对于隐私保护的差异化需求，确定出可以明文存储的暴露日志字段，并进一步根据暴露日志字段对预设条件的满足情况，在存储过程中体现出相应的差异化需求，具有较高的灵活性。
具体的，通过将特殊事件函数对应的暴露日志字段与预设条件进行比较，可以将满足预设条件的暴露日志字段以明文形式存储，而不满足预设条件的暴露日志字段或其他的收据内容则必然以密文形式存储。其中，预设条件的内容可以包括以下至少之一：相应的日志字段中包含预设内容、相应的日志字段的取值属于预设数值区间等。
预设内容可以包括：指定的一个或多个关键词，比如该关键词可以包括预定义的状态变量、预定义的中间变量等，使得当某一暴露日志字段包含作为关键词的状态变量或中间变量时，可以判定该暴露日志字段满足预设条件。
预设内容可以包括：预设值。比如该预设值可以为数值，该数值可与状态变量的取值等进行比较，以确定状态变量的取值是否符合预期；再比如该预设值可以为数值、字母、特殊符号等构成的字符串，该字符串可与交易发起方的账户地址、交易目标方的账户地址、日志主题等进行比较，以识别出特定的交易发起方、特定的交易目标方或特定的日志主题等。以预设内容为字符串为例，假定该字符串为某一账户地址，可使用户在针对该账户地址发起交易且交易类型对应的暴露日志字段包括To字段时，将To字段采用明文形式存储，而针对其他账户地址发起交易时，To字段不允许采用明文形式存储，避免泄露隐私。
预设数值区间可以表明相关收据字段的隐私保护需求情况，比如在转账场景中，预设数值区间可以为数值较小、隐私保护需求较低的数值区间，使得即便公开相关收据字段也不会造成严重的用户隐私泄露，但可以用于自动触发如DAPP客户端的相关操作，从而在隐私保护与便捷性之间取得一定平衡。因此，当暴露日志字段的取值处于该预设数值区间时，可以将该暴露日志字段以明文形式存储。
在一实施例中，预设条件可以包括所有日志字段对应的通用条件，即在收据数据中对应于特殊事件函数的日志中，该日志所含的所有日志字段存在统一的预设条件，使得该日志所含的所有暴露日志字段均需与该统一的预设条件进行比较。例如，当预设条件为“包含预设关键词”时，可以将特殊事件函数对应的日志中的所有暴露日志字段与该预设条件所含的关键词进行比较，以确定出包含该关键词的暴露日志字段，作为满足上述预设条件的暴露日志字段。
在一实施例中，预设条件可以包括每一日志字段分别对应的专用条件，即在收据数据中对应于特殊事件函数的日志中，该日志所含的各个日志字段分别存在对应的预设条件，使得该日志所含的每一暴露日志字段被用于与对应的预设条件进行比较。不同日志字段对应的预设条件之间相互独立，但可能相同，也可能不同。例如，From字段和To字段对应的预设条件可以为“是否包含预设内容”，且该预设内容可以为预设的账户地址，表明由该账户地址发起或针对该账户地址发起的交易，允许将From字段或To字段以明文形式存储(可以在From字段或To字段属于暴露日志字段时以明文形式存储)。再例如，Topic字段对应的预设条件可以为“是否属于预设取值区间”，而Topic字段中可以记录相关事件引用的状态变量的取值，譬如转账场景下可以包括代表“转账金额”的状态变量，表明转账金额处于预设取值区间(通常可以为较小金额对应的小额数值区间)时，允许将该转账金额以明文形式存储(可以在Topic字段属于暴露日志字 段时以明文形式存储)。
在一实施例中，预设条件可以位于交易中，使得不同交易所采用的预设条件可以存在差异，以满足不同交易所面临的需求差异；当然，不同交易也可以采用相同的预设条件。预设条件的不同可以表现为：预设条件的内容、预设条件适用的收据字段、对暴露日志字段是否满足预设条件进行判断的处理逻辑中的至少一个维度的差异。
在一实施例中，预设条件可以位于交易调用的智能合约中，或者预设条件可以位于交易调用的智能合约所调用的另一智能合约中，使得交易可以通过选取所调用的智能合约，以确定是否使用相应的预设条件。智能合约可由交易发起方自身或其他任意用户预先创建；当然，如果智能合约存在相应的调用条件，那么需要在该调用条件被满足时才能够使得上述交易调用该智能合约，比如该调用条件可以包括：交易发起方属于预设白名单、交易发起方不属于预设黑名单或其他条件。
在一实施例中，预设条件可以位于***合约或链代码中，使得该预设条件为适用于区块链上的所有交易的全局条件，而区别于上述的交易或智能合约所含的预设条件，使得即便交易或交易调用的智能合约并未包含预设条件的情况下，可以基于***合约或链代码中定义的预设条件，并结合交易发起方的用户类型，确定日志字段的存储方式。
需要指出的是：交易或智能合约所含的预设条件，与链代码或***合约所含的预设条件之间并不矛盾：两者可以分别包含不同维度的预设条件，比如预设条件适用的日志字段不同；或者，当两者包含的预设条件之间存在冲突时，可以默认为优先采用交易或智能合约所含的预设条件，或者优先采用链代码或***合约所含的预设条件，这取决于预定义的选择逻辑。
在图3所示实施例的基础上，本说明书可以进一步识别交易对应的智能合约的代码所含的暴露标识符和交易发起方的用户类型，从而同时根据智能合约所含的特殊事件函数、暴露标识符标明的对象和交易发起方的用户类型，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，以在交易发起方属于预设用户类型时，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储，所述至少一部分收据内容匹配于所述暴露标识符标明的对象。
例如，在上述的代码示例2中，通过在智能合约的代码最前方添加暴露标识符 plain，使得智能合约的代码被执行后，产生的收据数据中的所有字段均允许以明文形式进行存储。具体的，当交易发起方属于预设用户类型时，对于收据数据中由特殊事件函数产生的日志，允许该日志对应的所有收据内容以明文形式进行存储。当然，在其他实施例中，也可以具体指明需要明文存储的字段。比如，通过暴露标识符对From字段进行标注时，可使得智能合约的代码被执行后，当交易发起方属于预设用户类型时，对于收据数据中由特殊事件函数产生的日志，允许From字段对应的收据内容以明文形式进行存储，那么后续可以针对该From字段中的收据内容实施检索操作，比如可以统计某一账户所发起的交易量等。
再例如，在上述的代码示例3中，通过在状态变量“price”的类型int之前添加暴露标识符“plain”(或者，可以将暴露标识符plain置于类型int之后)，使得智能合约的代码被执行后，当交易发起方属于预设用户类型时，对于收据数据中由特殊事件函数产生的日志，允许与状态变量“price”相关的收据内容以明文形式进行存储(前提是交易发起方属于预设用户类型)，那么后续可以针对与状态变量“price”相关的收据内容实施检索操作。
在图3所示实施例的基础上，本说明书可以进一步识别交易对应的智能合约的代码所含的暴露标识符和交易类型对应的暴露字段，从而同时根据智能合约所含的特殊事件函数、暴露标识符标明的对象和交易类型对应的暴露字段，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储，所述至少一部分收据内容包括由所述暴露标识符标明的暴露字段。
例如，在上述的代码示例2中，在智能合约的代码最前方添加暴露标识符plain，仅从编程语言的维度而言，该暴露标识符plain表明：使得智能合约的代码被执行后，产生的收据数据中的所有字段均允许以明文形式进行存储，那么后续可以针对这些字段中的收据内容实施检索操作，比如对于From字段而言，可以用于统计某一账户所发起的交易量等。而通过进一步结合交易类型和事件函数等维度，对收据数据的存储方案可能存在不同。
在智能合约的代码中，暴露标识符可以标明一个或多个字段，这些字段在收据数据中存在对应的收据内容。不同类型的交易往往存在不同的隐私保护需求，可以允许相应的暴露字段以明文形式存储。而特殊事件函数被执行后，收据数据中包含对应于特 殊事件函数的日志，该日志实际为收据数据中的部分收据内容。而本说明书中通过对暴露标识符、交易类型和特殊事件函数进行综合考量，可以筛选出上述三部分收据内容的交叉内容，并针对该交叉内容实施明文存储，收据数据的其余内容均采用密文存储。
由于暴露标识符为智能合约的编程语言中所定义的全局性标识，因而只要在智能合约中写入暴露标识符后，就难以修改该暴露标识符所标明的字段。而交易类型与编程语言无关，可由用户根据实际需求进行选择；同时，特殊事件函数的定义也不一定基于编程语言实现，比如在基于特殊事件函数列表等方式记录特殊事件函数时，即便智能合约中包含的某一事件函数原本属于特殊事件函数，也可以通过对特殊事件函数列表进行更改的方式，将原有的特殊事件函数更新为普通事件函数，从而避免该事件函数产生的日志以明文形式存储，或者将原有的普通事件函数更新为特殊事件函数，使得该事件函数产生的日志中的至少一部分内容以明文形式存储。
以上述的代码示例2为例：假定事件currentPrice原本并未记录于特殊事件函数列表中，即事件currentPrice对应于普通事件函数，那么即便在智能合约的代码中添加了暴露标识符plain，事件currentPrice产生的日志中的各个字段(包括暴露字段)仍以密文形式存储。但是，如果将事件currentPrice添加至特殊事件函数列表中，那么代码示例2不需要调整的情况下，即可使得事件currentPrice对应的日志中的暴露字段以明文形式存储；比如，当From字段和To字段为暴露字段时，事件currentPrice所产生日志中的From字段和To字段将以明文形式存储，而其余字段则以密文形式存储。
需要指出的是：在上述的代码示例2中，通过在代码最前方声明“plain”，该暴露标识符“plain”所标明的字段为收据数据中的所有字段，且这些字段均为合约级字段，使得第一区块链节点在存储收据数据时，收据数据中所有对应于该合约级字段的收据内容，均被允许以明文形式存储。当然，如果代码示例2中通过暴露标识符标注了譬如From字段，那么该From字段为上述的合约级字段，当该From字段进一步属于交易类型对应的暴露字段时，可使第一区块链节点在存储收据数据时，收据数据中所有对应于该From字段的收据内容，均被允许以明文形式存储。
当智能合约的代码中包含多个事件函数时，在多个事件函数分别产生的各自对应的Logs字段中，均可能存在属于合约级字段的暴露字段；进一步地，可以通过识别各个事件函数的类型为普通事件函数或特殊事件函数，从而将所有特殊事件函数所产生的日志中属于合约级字段的暴露字段以明文形式存储。例如，在上述的代码示例4中，与代码示例2相类似地，暴露标识符“plain”位于智能合约的代码最前方，使得收据数 据中的所有字段均被标注为合约级字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：假定From字段为交易类型对应的暴露字段，并且事件currentPrice1对应于特殊事件函数列表中定义的特殊事件函数、事件currentPrice2对应于普通事件函数，那么在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1包含的From字段以明文形式存储、日志Log2包含的From字段以密文形式存储；类似地，日志Log1中属于暴露字段的其他字段也以明文形式存储、非暴露字段以密文形式存储，而日志Log2的所有字段均以密文形式存储。并且，如果通过对特殊事件函数列表进行更新后，将事件currentPrice2更新为对应于特殊事件函数，那么日志Log2包含的属于暴露字段的所有字段将以明文形式存储，而无需对智能合约的代码做任何变动。
对于上述的合约级字段而言，可以通过前述的类型标识符来标明智能合约所含的事件函数是否为特殊事件函数。
例如，在上述的代码示例5中，与代码示例2相类似地，合约级字段包括收据数据中的所有字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：由于事件currentPrice1在包含如前所述的类型标识符expose，使得该事件currentPrice1被标注为对应于特殊事件函数，而事件currentPrice2并未包含类型标识符expose，使得事件currentPrice2被标注为对应于普通事件函数，那么在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1中对应于交易类型的所有暴露字段均以明文形式存储、日志Log2包含的所有字段均以密文形式存储。
虽然类型标识符与暴露标识符相类似的，都是智能合约的编程语言中所定义的全局性标识，但是暴露标识符作用于合约级字段、类型标识符作用于事件函数，使得通过将暴露标识符与类型标识符配合使用，仅需单次添加暴露标识符即可设定形成上述的合约级字段，并且进而可以灵活地标注希望对合约级字段进行明文存储的事件函数，尤其是当智能合约中包含的事件函数的数量较多、事件函数中涉及的字段的数量较多时，仅需添加类似于上述的“plain”即可，无需针对每一事件函数分别实施设定操作，可以简化代码逻辑、防止错标或漏标。
除了合约级字段之外，暴露标识符标明的字段可以包括：对应于智能合约中定义的至少一个事件的事件级字段，使得第一区块链节点在存储收据数据时，可以确定出所述至少一个事件对应的特殊事件函数产生的日志，并将确定出的日志中属于事件级字段的暴露字段以明文形式存储。尤其是，当智能合约中包含多个事件时，可以针对至少 一部分事件设定上述的事件级字段，使得这部分事件对应的日志中属于事件级字段的暴露字段以明文形式存储，而这部分事件对应的日志中的其他字段、其余事件对应的收据内容均以密文形式存储。以From字段为例，在上述的代码示例8中，事件currentPrice1虽然未添加暴露标识符“plain”，但是包含了内容“from”，该内容“from”对应于From字段，用于表明事件currentPrice1所产生日志中的From字段需要以明文形式存储，因而该内容“from”既属于上述的暴露标识符，又标明了需要明文存储的From字段。并且，由于内容“from”位于事件currentPrice1中，因而From字段为事件级字段，使得当From字段为交易类型对应的暴露字段且该事件currentPrice1对应于特殊事件函数时，在该事件currentPrice1对应产生的日志Logs中，From字段将以明文形式进行存储、其他字段以密文形式存储。而对于代码示例8所含的另一事件currentPrice2，由于并未针对该事件currentPrice2添加暴露标识符，因而不论该事件currentPrice2对应于特殊事件函数或普通事件函数，所产生的日志Logs均以密文形式存储。
上述的关键词“from”指明了将From字段设定为事件级字段；而在其他实施例中，也可以并不指明具体的字段。例如，可以将上述的代码示例5调整为下述的代码示例11：
Contract Example{
int price；
int price1；
plain event currentPrice1(int price)；
event currentPrice2(int price1)；
…
在上述的代码示例11中，通过在事件currentPrice1之前添加暴露标识符“plain”，可以将该事件currentPrice1所产生的日志中的所有字段均作为上述的事件级字段，譬如前述的From字段、To字段、Topic字段、Log Data字段等。那么，当该事件currentPrice1对应于特殊事件函数时，可以从该事件currentPrice1所产生日志中的确定出既属于上述的事件级字段又属于交易类型对应的暴露字段的日志字段，以采用明文形式存储；如果上述的From字段、To字段、Topic字段、Log Data字段等均为暴露字段，那么相当于将该事件currentPrice1对应的所有收据内容(比如产生的日志)均以明文形式存储。
在上述的代码示例8、11等对应的实施例中，即对于事件级字段而言，可以通 过特殊事件函数列表或者类型标识符的方式识别智能合约所含的事件函数是否为特殊事件函数，此处不再一一赘述。
在图3所示实施例的基础上，本说明书可以进一步识别交易对应的智能合约的代码所含的暴露标识符和收据数据中满足预设条件的收据内容，从而同时根据智能合约所含的特殊事件函数、暴露标识符标明的对象和收据内容对预设条件的满足情况，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储，所述至少一部分收据内容匹配于所述暴露标识符标明的对象且满足预设条件。
本说明书通过在一定程度上暴露收据内容，以用于实现对DAPP客户端的驱动或其他的功能扩展。并且，本说明书通过综合考虑暴露标识符标明的对象、特殊事件函数产生的日志和预设条件，可以准确选取用于明文存储的收据内容，即同时满足“匹配于暴露标识符标明的对象”、“属于特殊事件函数产生的日志”和“满足预设条件”的收据内容，从而在满足上述功能扩展需求的同时，确保绝大部分的用户隐私能够得到保护。尤其是，当第一区块链节点是根据区块链网络上记载的信息(如特殊事件函数列表)来识别特殊事件函数时，可以在智能合约已经创建之后，通过对“特殊事件函数”进行更新，以调整收据数据的存储方式，比如将原本明文存储的收据内容改为密文存储，或者将原本密文存储的收据内容改为明文存储。
在图3所示实施例的基础上，本说明书可以进一步识别交易发起方的用户类型和交易类型对应的暴露字段，从而同时根据智能合约所含的特殊事件函数、交易发起方的用户类型和交易类型对应的暴露字段，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，当交易发起方属于预设用户类型时，使对应于所述特殊事件函数的日志中的暴露字段以明文形式存储、所述收据数据的其余内容以密文形式存储。可见，智能合约所含的事件可以分为特殊事件函数和普通事件函数，其中：普通事件函数所产生的日志采用密文形式进行存储，以实现隐私保护；特殊事件函数所产生的日志则需要在满足隐私保护需求的前提下，将至少一部分日志字段(例如上文所述的暴露字段)以明文形式进行存储，从而可以针对该部分日志字段的内容实施检索，以驱动相关操作的实施。当然，在针对特殊事件函数所产生的日志中的暴露字段进行存储时，本说明书还进一步参考交易发起方的用户类型，该用户类型可以体现出交易发起方对于收据数据的隐私保护需求，从而基于该隐私保护需求确定对暴露 字段的存储方式：例如，当交易发起方属于预设用户类型时，可以对特殊事件函数所产生的日志中的暴露字段以明文形式存储，否则将采用密文形式存储。
在保护用户隐私的前提下，通过对交易类型予以识别，可以根据不同类型的交易对于隐私保护的差异化需求，确定出允许明文存储的暴露字段；进一步地，不同类型的用户对于隐私保护的需求并不相同，比如当交易发起方属于预设用户类型时，允许通过暴露部分收据内容来触发DAPP客户端等实施相关后续操作，以提升便捷度，而其他类型的用户可能不允许暴露隐私信息；更进一步地，即便对于预设用户类型的交易发起方而言，仍然在不同场景下存在差异化的隐私保护需求，可以根据交易调用的智能合约所含的事件函数的类型，在存储过程中体现出不同类型的事件函数对于隐私保护的差异化需求，例如特殊事件函数涉及的暴露字段以明文形式存储，而特殊事件函数涉及的非暴露字段、普通事件函数所涉及的所有收据字段等，均以密文形式存储，具有较高的灵活性。
在图3所示实施例的基础上，本说明书可以进一步识别交易发起方的用户类型和收据数据中满足预设条件的收据内容，从而同时根据智能合约所含的特殊事件函数、交易发起方的用户类型和收据内容对预设条件的满足情况，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，使得当交易发起方属于预设用户类型时，对应于所述特殊事件函数的日志中满足预设条件的至少一个日志字段以明文形式存储、所述收据数据的其余内容以密文形式存储，当交易发起方不属于所述预设用户类型时，所述收据数据以密文形式存储。
在图3所示实施例的基础上，本说明书可以进一步识别交易类型对应的暴露字段和收据数据中满足预设条件的收据内容，从而同时根据智能合约所含的特殊事件函数、交易类型对应的暴露字段和收据内容对预设条件的满足情况，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中满足预设条件的暴露字段以明文形式存储、所述收据数据的其余内容以密文形式存储。可见，智能合约所含的事件可以分为特殊事件函数和普通事件函数，其中：普通事件函数所产生的日志采用密文形式进行存储，以实现隐私保护；特殊事件函数所产生的日志则需要在满足隐私保护需求的前提下，将至少一部分日志字段(例如上文所述的暴露字段)以明文形式进行存储，从而可以针对该部分日志字段的内容实施检索，以驱动相关操作的实施。当然，在针对特殊事件函数所产生的日志中的暴露字段进行存储时，本说明书还进一步参考预定义的相关条件(即预设条件)， 该预设条件可以用于判断与识别出暴露字段所含内容的隐私程度：当暴露字段满足该预设条件时，表明隐私程度相对较低，可以采用明文形式存储，而当暴露字段不满足该预设条件时，表明隐私程度相对较高，应当采用密文形式存储。
在保护用户隐私的前提下，通过对交易类型予以识别，可以根据不同类型的交易对于隐私保护的差异化需求，确定出允许明文存储的暴露字段；进一步地，由于不同事件函数往往涉及到不同信息，使得不同事件函数对应于不同的隐私保护需求，比如涉及到转账金额的事件函数的隐私保护需求相对较高、涉及到存证的事件函数的隐私保护需求相对较低(此处仅用于举例；实际上，转账金额较低的情况下，相关事件函数的隐私保护需求也可能相对较低，以及存证内容比较重要的情况下，相关事件函数的隐私保护需求也可能相对较高)，因而可以将隐私保护需求相对较低的事件函数配置为上述的特殊事件函数，并在特殊事件函数产生的日志中包含上述的暴露字段时，允许暴露该暴露字段对应的收据内容；更进一步地，即便对于特殊事件函数所产生日志中的暴露字段而言，仍然在不同场景下存在差异化的隐私保护需求，可以根据暴露字段对预设条件的满足情况，在存储过程中体现出对隐私保护的差异化需求和处理：通过将收据数据中的暴露字段与预设条件进行比较，可以将满足预设条件的暴露字段以明文形式存储，而不满足预设条件的暴露字段或其他的收据字段则必然以密文形式存储。例如，假定特殊事件函数涉及存证操作，当该特殊事件函数所产生的日志包含上述的暴露字段，并且该暴露字段中的存证内容包含预设条件涉及的关键词时，可以将该暴露字段以明文形式存储，否则以密文形式存储。
在图3所示实施例的基础上，本说明书可以进一步识别交易对应的智能合约的代码所含的暴露标识符、交易发起方的用户类型和交易类型对应的暴露字段，从而同时根据智能合约所含的特殊事件函数、暴露标识符标明的对象、交易发起方的用户类型和交易类型对应的暴露字段，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，以在交易发起方属于预设用户类型时，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储，所述至少一部分收据内容匹配于所述暴露标识符标明的暴露字段。
在上述的代码示例2中，在智能合约的代码最前方添加暴露标识符plain，使得智能合约的代码被执行后，当交易发起方属于预设用户类型时，对于收据数据中由特殊事件函数产生的日志，允许该智能合约所属交易的交易类型对应的暴露字段对应的收据 内容以明文形式进行存储，比如当日志中的From字段属于暴露字段、To字段并不属于暴露字段时，可以将收据数据中所有日志的From字段以明文形式存储、To字段以密文形式存储，那么后续可以针对该From字段中的收据内容实施检索操作，比如可以统计某一账户所发起的交易量等。
在智能合约的代码中，暴露标识符可以标明一个或多个字段，这些字段在收据数据中存在对应的收据内容。交易类型对应的暴露字段可以为收据数据中的一个或多个字段，这些字段在收据数据中存在对应的收据内容。特殊事件函数被执行后，收据数据中包含对应于特殊事件函数的日志，该日志实际为收据数据中的部分收据内容。而本说明书中，在交易发起方属于预设用户类型的情况下，通过对暴露标识符、交易类型和特殊事件函数进行综合考量，可以筛选出上述三部分收据内容的交叉内容，并针对该交叉内容实施明文存储，收据数据的其余内容均采用密文存储。
由于暴露标识符为智能合约的编程语言中所定义的全局性标识，因而只要在智能合约中写入暴露标识符后，就难以修改该暴露标识符所标明的字段。而用户类型则取决于交易发起方、与编程语言无关，使得不同交易发起方即便调用同一智能合约时，对收据数据的存储方式(密文或明文)也可能存在不同。交易类型也可以由交易发起方根据需求而选取，以表明交易发起方的实际需求。同时，特殊事件函数的定义并不一定基于编程语言实现，比如在基于特殊事件函数列表等方式记录特殊事件函数时，即便智能合约中包含的某一事件函数原本属于特殊事件函数，也可以通过对特殊事件函数列表进行更改的方式，将原有的特殊事件函数更新为普通事件函数，从而避免该事件函数产生的日志以明文形式存储，或者将原有的普通事件函数更新为特殊事件函数，使得该事件函数产生的日志中的至少一部分内容以明文形式存储。因此，通过由不同用户对智能合约进行调用，或者发起不同类型的交易，或者调整智能合约所含事件函数的类型，可以跳脱暴露标识符的限制，调整需要明文或密文存储的收据内容。
以上述的代码示例2为例：假定事件currentPrice原本并未记录于特殊事件函数列表中，即事件currentPrice对应于普通事件函数，那么即便在智能合约的代码中添加了暴露标识符plain且交易发起方属于预设用户类型，事件currentPrice产生的日志中的各个字段(包括暴露字段)仍以密文形式存储。但是，如果将事件currentPrice添加至特殊事件函数列表中，那么代码示例2不需要调整的情况下，当交易发起方属于预设用户类型时，可使事件currentPrice对应的日志中的暴露字段以明文形式存储。
需要指出的是：在上述的代码示例2中，通过在代码最前方声明“plain”，该 暴露标识符“plain”所标明的字段为收据数据中的所有字段，且这些字段均为合约级字段，使得在交易发起方属于预设用户类型且该合约级字段属于暴露字段时，使事件currentPrice产生的日志中对应于该合约级字段的收据内容，均被允许以明文形式存储。当然，如果代码示例2中通过暴露标识符标注了譬如From字段，那么该From字段为上述的合约级字段，当该From字段进一步属于交易类型对应的暴露字段时，可在交易发起方属于预设用户类型的情况下，使第一区块链节点在存储收据数据时，收据数据中所有对应于该From字段的收据内容，均被允许以明文形式存储。
尤其是，当智能合约的代码中包含多个事件函数时，在多个事件函数分别产生的各自对应的Logs字段中，均可能存在合约级字段所对应的收据内容；进一步地，可以通过识别交易发起方所属的用户类型、交易的交易类型对应的暴露字段以及各个事件函数的类型为普通事件函数或特殊事件函数，从而在交易发起方属于预设用户类型且合约级字段属于暴露字段的情况下，将所有特殊事件函数所产生的日志中对应于合约级字段的收据内容以明文形式存储。例如，在上述的代码示例4中，与代码示例2相类似地，暴露标识符“plain”位于智能合约的代码最前方，使得收据数据中的所有字段均被标注为合约级字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：假定事件currentPrice1对应于特殊事件函数列表中定义的特殊事件函数、事件currentPrice2对应于普通事件函数，那么在交易发起方属于预设用户类型且From字段属于暴露字段的情况下，在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1包含的From字段以明文形式存储、日志Log2包含的From字段以密文形式存储；类似地，日志Log1中属于暴露字段的其他字段也以明文形式存储、非暴露字段以密文形式存储，而日志Log2的所有字段均以密文形式存储。并且，如果通过对特殊事件函数列表进行更新后，将事件currentPrice2更新为对应于特殊事件函数，那么日志Log2包含的属于暴露字段的所有字段将以明文形式存储，而无需对智能合约的代码做任何变动。
对于上述的合约级字段而言，可以通过前述的类型标识符来标明智能合约所含的事件函数是否为特殊事件函数。例如，在上述的代码示例5中，与代码示例2相类似地，合约级字段包括收据数据中的所有字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：由于事件currentPrice1在包含如前所述的类型标识符expose，使得该事件currentPrice1被标注为对应于特殊事件函数，而事件currentPrice2并未包含类型标识符expose，使得事件currentPrice2被标注为对应于普通事件函数，那么在交易发起方属于预设用户类型的情况下，在事件currentPrice1和事件currentPrice2分别产生的 日志Log1、Log2中，日志Log1中对应于交易类型的所有暴露字段均以明文形式存储、日志Log2包含的所有字段均以密文形式存储。
除了合约级字段之外，暴露标识符标明的字段可以包括：对应于智能合约中定义的至少一个事件的事件级字段，使得在交易发起方属于预设用户类型且该事件级字段属于暴露字段的情况下，第一区块链节点将特殊事件函数产生的收据内容中对应于该事件级字段的部分以明文形式存储。尤其是，当智能合约中包含多个事件时，可以针对至少一部分事件设定上述的事件级字段，使得这部分事件产生的日志中对应于上述事件级字段的收据内容以明文形式存储，而这部分事件产生的日志中的其余收据内容、其余事件对应的收据内容均以密文形式存储。以From字段为例，在上述的代码示例8中，事件currentPrice1虽然未添加暴露标识符“plain”，但是包含了内容“from”，该内容“from”对应于From字段，用于表明事件currentPrice1所产生日志中的From字段需要以明文形式存储，因而该内容“from”既属于上述的暴露标识符，又标明了需要明文存储的From字段。并且，由于内容“from”位于事件currentPrice1中，因而From字段为事件级字段，使得在交易发起方属于预设用户类型且From字段属于暴露字段的情况下，当该事件currentPrice1对应于特殊事件函数时，在该事件currentPrice1对应产生的日志Logs中，From字段将以明文形式进行存储、其他字段以密文形式存储。而对于代码示例8所含的另一事件currentPrice2，由于并未针对该事件currentPrice2添加暴露标识符，因而不论该事件currentPrice2对应于特殊事件函数或普通事件函数，所产生的日志Logs均以密文形式存储。该代码示例5对应的实施例中，即对于事件级字段而言，可以通过特殊事件函数列表或者类型标识符的方式识别智能合约所含的事件函数是否为特殊事件函数，此处不再一一赘述。
在图3所示实施例的基础上，本说明书可以进一步识别交易对应的智能合约的代码所含的暴露标识符、交易发起方的用户类型和收据数据中满足预设条件的收据内容，从而同时根据智能合约所含的特殊事件函数、暴露标识符标明的对象、交易发起方的用户类型和收据内容对预设条件的满足情况，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，以在交易发起方属于预设用户类型时，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储，所述至少一部分收据内容匹配于所述暴露标识符标明的对象且满足预设条件，在交易发起方不属于所述预设用户类型时，所述收据数据以密文形式存储。
在图3所示实施例的基础上，本说明书可以进一步识别交易对应的智能合约的代码所含的暴露标识符、交易类型对应的暴露字段和收据数据中满足预设条件的收据内容，从而同时根据智能合约所含的特殊事件函数、暴露标识符标明的对象、交易类型对应的暴露字段和收据内容对预设条件的满足情况，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储，所述至少一部分收据内容包括由所述暴露标识符标明且满足预设条件的暴露字段。
在上述的代码示例2中，在智能合约的代码最前方添加暴露标识符plain，仅从编程语言的维度而言，暴露标识符plain表明：使得智能合约的代码被执行后，产生的收据数据中的所有字段均允许以明文形式进行存储，那么后续可以针对这些字段中的收据内容实施检索操作，比如对于From字段而言，可以用于统计某一账户所发起的交易量等。而通过进一步结合交易类型、事件函数和预设条件等维度，对收据数据的存储方案可能存在不同，仍以From字段为例：收据数据中的From字段可能并非均以明文形式存储，以事件currentPrice为例，当该事件currentPrice为特殊事件函数且From字段满足预设条件时，将该事件currentPrice所产生日志中的From字段以明文形式存储，否则以密文形式存储。
由于暴露标识符为智能合约的编程语言中所定义的全局性标识，因而只要在智能合约中写入暴露标识符后，就难以修改该暴露标识符所标明的字段。而预设条件并不一定在暴露标识符所处的智能合约中基于编程语言实现，因而通过由不同用户对智能合约进行调用，或者调整所采用的预设条件，可以跳脱暴露标识符的限制，调整需要明文或密文存储的收据内容。
除了上述的预设条件之外，交易类型与编程语言无关，可由用户根据实际需求进行选择；同时，特殊事件函数的定义也不一定基于编程语言实现，比如在基于特殊事件函数列表等方式记录特殊事件函数时，即便智能合约中包含的某一事件函数原本属于特殊事件函数，也可以通过对特殊事件函数列表进行更改的方式，将原有的特殊事件函数更新为普通事件函数，从而避免该事件函数产生的日志以明文形式存储，或者将原有的普通事件函数更新为特殊事件函数，使得该事件函数产生的日志中的至少一部分内容以明文形式存储。
以上述的代码示例2为例：假定事件currentPrice原本并未记录于特殊事件函数 列表中，即事件currentPrice对应于普通事件函数，那么即便在智能合约的代码中添加了暴露标识符plain且From字段属于暴露字段，事件currentPrice产生的日志中的各个字段(包括暴露字段)仍以密文形式存储。但是，如果将事件currentPrice添加至特殊事件函数列表中，那么代码示例2不需要调整的情况下，即可使得事件currentPrice对应的日志中的暴露字段以明文形式存储；比如，当From字段和To字段为暴露字段时，事件currentPrice所产生日志中的From字段和To字段将以明文形式存储，而其余字段则以密文形式存储。
需要指出的是：在上述的代码示例2中，通过在代码最前方声明“plain”，该暴露标识符“plain”所标明的字段为收据数据中的所有字段，且这些字段均为合约级字段，使得第一区块链节点在存储收据数据时，收据数据中所有对应于该合约级字段的收据内容，均被允许以明文形式存储。当然，如果代码示例2中通过暴露标识符标注了譬如From字段，那么该From字段为上述的合约级字段，当该From字段进一步属于交易类型对应的暴露字段时，可使第一区块链节点在存储收据数据时，收据数据中所有对应于该From字段且满足预设条件的收据内容，均被允许以明文形式存储。
当智能合约的代码中包含多个事件函数时，在多个事件函数分别产生的各自对应的Logs字段中，均可能存在属于合约级字段的暴露字段；进一步地，可以通过识别各个事件函数的类型为普通事件函数或特殊事件函数，从而将所有特殊事件函数所产生的日志中属于合约级字段的暴露字段以明文形式存储。例如，在上述的代码示例4中，与代码示例2相类似地，暴露标识符“plain”位于智能合约的代码最前方，使得收据数据中的所有字段均被标注为合约级字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：假定From字段为交易类型对应的暴露字段，并且事件currentPrice1对应于特殊事件函数列表中定义的特殊事件函数、事件currentPrice2对应于普通事件函数，那么在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1包含的From字段在满足预设条件时以明文形式存储、日志Log2包含的From字段以密文形式存储；类似地，日志Log1中属于暴露字段的其他字段也以明文形式存储、非暴露字段以密文形式存储，而日志Log2的所有字段均以密文形式存储。并且，如果通过对特殊事件函数列表进行更新后，将事件currentPrice2更新为对应于特殊事件函数，那么日志Log2包含的属于暴露字段且满足预设条件的所有字段将以明文形式存储，而无需对智能合约的代码做任何变动。
对于上述的合约级字段而言，可以通过前述的类型标识符来标明智能合约所含 的事件函数是否为特殊事件函数。例如，在上述的代码示例5中，与代码示例2相类似地，合约级字段包括收据数据中的所有字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：由于事件currentPrice1在包含如前所述的类型标识符expose，使得该事件currentPrice1被标注为对应于特殊事件函数，而事件currentPrice2并未包含类型标识符expose，使得事件currentPrice2被标注为对应于普通事件函数，那么在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1中对应于交易类型的所有暴露字段在满足预设条件的情况下均以明文形式存储、日志Log2包含的所有字段均必然以密文形式存储。
虽然类型标识符与暴露标识符相类似的，都是智能合约的编程语言中所定义的全局性标识，但是暴露标识符作用于合约级字段、类型标识符作用于事件函数，使得通过将暴露标识符与类型标识符配合使用，仅需单次添加暴露标识符即可设定形成上述的合约级字段，并且进而可以灵活地标注希望对合约级字段进行明文存储的事件函数，尤其是当智能合约中包含的事件函数的数量较多、事件函数中涉及的字段的数量较多时，仅需添加类似于上述的“plain”即可，无需针对每一事件函数分别实施设定操作，可以简化代码逻辑、防止错标或漏标。
除了合约级字段之外，暴露标识符标明的字段可以包括：对应于智能合约中定义的至少一个事件的事件级字段，使得第一区块链节点在存储收据数据时，可以确定出所述至少一个事件对应的特殊事件函数产生的日志，并将确定出的日志中属于事件级字段且满足预设条件的暴露字段以明文形式存储。尤其是，当智能合约中包含多个事件时，可以针对至少一部分事件设定上述的事件级字段，使得这部分事件对应的日志中属于事件级字段且满足预设条件的暴露字段以明文形式存储，而这部分事件对应的日志中的其他字段、其余事件对应的收据内容均以密文形式存储。以From字段为例，在上述的代码示例8中，事件currentPrice1虽然未添加暴露标识符“plain”，但是包含了内容“from”，该内容“from”对应于From字段，用于表明事件currentPrice1所产生日志中的From字段需要以明文形式存储，因而该内容“from”既属于上述的暴露标识符，又标明了需要明文存储的From字段。并且，由于内容“from”位于事件currentPrice1中，因而From字段为事件级字段，使得当From字段为交易类型对应的暴露字段且该事件currentPrice1对应于特殊事件函数时，在该事件currentPrice1对应产生的日志Logs中，From字段在满足预设条件的情况下将以明文形式进行存储、在未满足预设条件的情况下以密文形式进行存储，而其他字段必然以密文形式存储。而对于代码示例5所含的另一事件currentPrice2，由于并未针对该事件currentPrice2添加暴露标识符，因而不论该事件 currentPrice2对应于特殊事件函数或普通事件函数，所产生的日志Logs均以密文形式存储。
上述的关键词“from”指明了将From字段设定为事件级字段；而在其他实施例中，也可以并不指明具体的字段。例如，在上述的代码示例11中，通过在事件currentPrice1之前添加暴露标识符“plain”，可以将该事件currentPrice1所产生的日志中的所有字段均作为上述的事件级字段，譬如前述的From字段、To字段、Topic字段、Log Data字段等。那么，当该事件currentPrice1对应于特殊事件函数时，可以从该事件currentPrice1所产生日志中的确定出既属于上述的事件级字段又属于交易类型对应的暴露字段的日志字段，并在确定出的日志字段满足预设条件时采用明文形式存储；如果上述的From字段、To字段、Topic字段、Log Data字段等均为暴露字段且满足预设条件，那么相当于将该事件currentPrice1对应的所有收据内容(比如产生的日志)均以明文形式存储。
在上述的代码示例8、11等对应的实施例中，即对于事件级字段而言，可以通过特殊事件函数列表或者类型标识符的方式识别智能合约所含的事件函数是否为特殊事件函数，此处不再一一赘述。
在图3所示实施例的基础上，本说明书可以进一步识别交易对应的智能合约的代码所含的暴露标识符、交易发起方的用户类型、交易类型对应的暴露字段和收据数据中满足预设条件的收据内容，从而同时根据智能合约所含的特殊事件函数、暴露标识符标明的对象、交易发起方的用户类型、交易类型对应的暴露字段和收据内容对预设条件的满足情况，确定对收据数据的存储方式。因此，上述的步骤308可以改进为：第一区块链节点存储所述收据数据，以在交易发起方属于预设用户类型时，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储，所述至少一部分收据内容匹配于所述暴露标识符标明的暴露字段且满足预设条件。
在上述的代码示例2中，在智能合约的代码最前方添加暴露标识符plain，使得智能合约的代码被执行后，当交易发起方属于预设用户类型时，对于收据数据中由特殊事件函数产生的日志，允许该智能合约所属交易的交易类型对应的暴露字段且满足预设条件的收据内容以明文形式进行存储，比如当日志中的From字段属于暴露字段、To字段并不属于暴露字段时，可以将收据数据中所有日志的From字段在满足预设条件时以明文形式存储、To字段以密文形式存储，那么后续可以针对该From字段中的收据内容实施检索操作，比如可以统计某一账户所发起的交易量等。
由于暴露标识符为智能合约的编程语言中所定义的全局性标识，因而只要在智能合约中写入暴露标识符后，就难以修改该暴露标识符所标明的字段。而用户类型则取决于交易发起方、与编程语言无关，使得不同交易发起方即便调用同一智能合约时，对收据数据的存储方式(密文或明文)也可能存在不同。交易类型也可以由交易发起方根据需求而选取，以表明交易发起方的实际需求。预设条件可以由交易发起方根据实际需求而选取，与编程语言无关。同时，特殊事件函数的定义并不一定基于编程语言实现，比如在基于特殊事件函数列表等方式记录特殊事件函数时，即便智能合约中包含的某一事件函数原本属于特殊事件函数，也可以通过对特殊事件函数列表进行更改的方式，将原有的特殊事件函数更新为普通事件函数，从而避免该事件函数产生的日志以明文形式存储，或者将原有的普通事件函数更新为特殊事件函数，使得该事件函数产生的日志中的至少一部分内容以明文形式存储。因此，通过由不同用户对智能合约进行调用，或者发起不同类型的交易，或者调整智能合约所含事件函数的类型，或者选用不同的预设条件，可以跳脱暴露标识符的限制，调整需要明文或密文存储的收据内容。
以上述的代码示例2为例：假定事件currentPrice原本并未记录于特殊事件函数列表中，即事件currentPrice对应于普通事件函数，那么即便在智能合约的代码中添加了暴露标识符plain且交易发起方属于预设用户类型，事件currentPrice产生的日志中的各个字段(包括暴露字段)仍以密文形式存储。但是，如果将事件currentPrice添加至特殊事件函数列表中，那么代码示例2不需要调整的情况下，当交易发起方属于预设用户类型时，可使事件currentPrice对应的日志中的暴露字段在满足预设条件的情况下以明文形式存储。
需要指出的是：在上述的代码示例2中，通过在代码最前方声明“plain”，该暴露标识符“plain”所标明的字段为收据数据中的所有字段，且这些字段均为合约级字段，使得在交易发起方属于预设用户类型且该合约级字段属于暴露字段时，使事件currentPrice产生的日志中对应于该合约级字段且满足预设条件的收据内容均被允许以明文形式存储。当然，如果代码示例2中通过暴露标识符标注了譬如From字段，那么该From字段为上述的合约级字段，当该From字段进一步属于交易类型对应的暴露字段时，可在交易发起方属于预设用户类型的情况下，使第一区块链节点在存储收据数据时，收据数据中所有对应于该From字段且满足预设条件的收据内容，均被允许以明文形式存储。
尤其是，当智能合约的代码中包含多个事件函数时，在多个事件函数分别产生 的各自对应的Logs字段中，均可能存在合约级字段所对应的收据内容；进一步地，可以通过识别交易发起方所属的用户类型、交易的交易类型对应的暴露字段、各个事件函数的类型为普通事件函数或特殊事件函数以及收据内容对预设条件的满足情况，从而在交易发起方属于预设用户类型且合约级字段属于暴露字段的情况下，将所有特殊事件函数所产生的日志中对应于合约级字段且满足预设条件的收据内容以明文形式存储。例如，在上述的代码示例4中，与代码示例2相类似地，暴露标识符“plain”位于智能合约的代码最前方，使得收据数据中的所有字段均被标注为合约级字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：假定事件currentPrice1对应于特殊事件函数列表中定义的特殊事件函数、事件currentPrice2对应于普通事件函数，那么在交易发起方属于预设用户类型且From字段属于暴露字段的情况下，在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1包含的From字段在满足预设条件的情况下以明文形式存储、在未满足预设条件的情况下以密文形式存储，而日志Log2包含的From字段必然以密文形式存储；类似地，日志Log1中属于暴露字段的其他字段在满足预设条件时也以明文形式存储、非暴露字段以密文形式存储，而日志Log2的所有字段均以密文形式存储。并且，如果通过对特殊事件函数列表进行更新后，将事件currentPrice2更新为对应于特殊事件函数，那么日志Log2包含的属于暴露字段的所有字段可以在满足预设条件的情况下以明文形式存储、在未满足预设条件的情况下以密文形式存储，而无需对智能合约的代码做任何变动。
对于上述的合约级字段而言，可以通过前述的类型标识符来标明智能合约所含的事件函数是否为特殊事件函数。例如，在上述的代码示例5中，与代码示例2相类似地，合约级字段包括收据数据中的所有字段；同时，智能合约中包含了事件currentPrice1和事件currentPrice2：由于事件currentPrice1在包含如前所述的类型标识符expose，使得该事件currentPrice1被标注为对应于特殊事件函数，而事件currentPrice2并未包含类型标识符expose，使得事件currentPrice2被标注为对应于普通事件函数，那么在交易发起方属于预设用户类型的情况下，在事件currentPrice1和事件currentPrice2分别产生的日志Log1、Log2中，日志Log1中对应于交易类型的所有暴露字段在满足预设条件的情况下以明文形式存储、在未满足预设条件的情况下以密文形式存储，而日志Log2包含的所有字段必然以密文形式存储。
除了合约级字段之外，暴露标识符标明的字段可以包括：对应于智能合约中定义的至少一个事件的事件级字段，使得在交易发起方属于预设用户类型且该事件级字段属于暴露字段的情况下，第一区块链节点将特殊事件函数产生的收据内容中对应于该事 件级字段且满足预设条件的部分以明文形式存储。尤其是，当智能合约中包含多个事件时，可以针对至少一部分事件设定上述的事件级字段，使得这部分事件产生的日志中对应于上述事件级字段且满足预设条件的收据内容以明文形式存储，而这部分事件产生的日志中的其余收据内容、其余事件对应的收据内容均以密文形式存储。以From字段为例，在上述的代码示例8中，事件currentPrice1虽然未添加暴露标识符“plain”，但是包含了内容“from”，该内容“from”对应于From字段，用于表明事件currentPrice1所产生日志中的From字段需要以明文形式存储，因而该内容“from”既属于上述的暴露标识符，又标明了需要明文存储的From字段。并且，由于内容“from”位于事件currentPrice1中，因而From字段为事件级字段，使得在交易发起方属于预设用户类型且From字段属于暴露字段的情况下，当该事件currentPrice1对应于特殊事件函数时，在该事件currentPrice1对应产生的日志Logs中，From字段在满足预设条件的情况下以明文形式进行存储、在未满足预设条件的情况下以密文形式存储，而其他字段必然以密文形式存储。而对于代码示例8所含的另一事件currentPrice2，由于并未针对该事件currentPrice2添加暴露标识符，因而不论该事件currentPrice2对应于特殊事件函数或普通事件函数，所产生的日志Logs均以密文形式存储。该代码示例8对应的实施例中，即对于事件级字段而言，可以通过特殊事件函数列表或者类型标识符的方式识别智能合约所含的事件函数是否为特殊事件函数，此处不再一一赘述。
与图3所示实施例相类似的，上述扩展后的各个实施例同样可以通过链代码实现相应的逻辑功能，或者采用链代码与***合约相结合的方式。其中，图3所示实施例采用的是与智能合约所含的事件函数相关的收据数据存储逻辑，而上述扩展后的实施例在此基础上还进一步考量下述因素中至少之一：暴露标识符标明的对象、交易发起方的用户类型、交易类型和收据数据中满足预设条件的收据内容。上述的一个或多个因素可以与用户类型相结合，以得到相应的收据数据存储逻辑。
当收据数据存储逻辑与暴露标识符标明的对象相关时，该收据数据存储逻辑包括基于暴露标识符对收据内容进行存储的逻辑，该逻辑用于指示第一区块链节点：针对暴露标识符标明的字段、暴露标识符未标明的字段等，分别采用何种方式存储相应的收据内容。
当收据数据存储逻辑与交易发起方的用户类型相关时，该收据数据存储逻辑包括：对用户类型的识别逻辑。对用户类型的识别逻辑用于指示第一区块链节点：识别交易发起方的用户类型。比如：***合约中可以记录有预定义的外部账户与用户类型之间 的关联关系，或者***合约中可以记录有用户类型字段的取值与用户类型之间的对应关系。具体可以参考上文中识别用户类型的相关描述，此处不再赘述。
当收据数据存储逻辑与交易的交易类型相关时，该收据数据存储逻辑包括：对交易类型的识别逻辑。对交易类型的识别逻辑用于指示第一区块链节点：识别交易发起方所发起的交易的类型。比如：根据交易所含的类型字段的取值，确定该交易对应的交易类型。具体可以参考上文中识别交易类型的相关描述，此处不再赘述。
当收据数据存储逻辑与收据数据中满足预设条件的收据内容相关时，该收据数据存储逻辑包括：对预设条件的确定逻辑。对预设条件的确定逻辑用于指示第一区块链节点：获取暴露标识符标明的对象所对应的收据内容所适用的预设条件。比如：获取适用于所有收据字段的通用条件，或者获取适用于暴露标识符标明的对象所对应的收据内容的所处字段的专用条件等。具体可以参考上文中预设条件的相关描述，此处不再赘述。
以下结合图6介绍本说明书一种基于事件函数类型的收据存储节点的实施例，包括：
接收单元61，接收经过加密的对应于智能合约的交易；
解密单元62，在可信执行环境中解密所述交易以获得所述智能合约，所述智能合约包含特殊事件函数；
执行单元63，在所述可信执行环境中执行所述智能合约，得到收据数据，所述收据数据包含对应于所述特殊事件函数的日志；
存储单元64，存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储。
可选的，所述至少一部分收据内容匹配于所述特殊事件函数对应的暴露日志字段。
可选的，所述特殊事件函数中包含被标明的所述暴露日志字段；或者，所述特殊事件函数中包含被标明的加密日志字段，所述暴露日志字段为其他日志字段。
可选的，确定所述特殊事件函数对应的暴露日志字段，包括：
获取预定义的特殊事件函数与暴露日志字段之间的映射关系，或者获取预定义的特殊事件函数与加密日志字段之间的映射关系；
根据所述智能合约包含的特殊事件函数和所述映射关系，确定所述特殊事件函 数对应的暴露日志字段。
可选的，所述映射关系记录于***合约中。
可选的，所述智能合约中的事件函数包含类型标识符，所述类型标识符用于将所述事件函数标记为特殊事件函数。
可选的，当所述智能合约包含的事件函数位于区块链上记录的特殊函数列表中时，所述智能合约包含的事件函数被判定为特殊事件函数。
可选的，存储单元64具体用于：
存储所述收据数据，使交易发起方属于预设用户类型的情况下，对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储。
可选的，通过下述方式确定所述交易发起方所属的用户类型：
确定所述交易发起方对应的外部账户；
查询区块链上记录的所述外部账户对应的用户类型，以作为所述交易发起方所属的用户类型。
可选的，所述外部账户包括记录于区块链上的用户类型字段，所述用户类型字段的取值对应于所述用户类型。
可选的，在创建所述外部账户时，所述用户类型被配置为关联至所述外部账户，使所述用户类型与所述外部账户之间的关联关系被记录于区块链中。
可选的，还包括：
更改单元65，根据管理用户发起的更改请求，更改所述外部账户对应的用户类型。
可选的，以明文形式存储的所述至少一部分收据内容满足下述规则中至少之一：
所述至少一部分收据内容匹配于由所述智能合约的代码所含的暴露标识符标明的对象；
所述至少一部分收据内容对应于所述交易的交易类型对应的暴露字段；
所述至少一部分收据内容所含的信息满足预设条件。
可选的，接收单元61接收的交易对应的智能合约，包括：
高级语言编写的智能合约；或，
字节码形式的智能合约。
可选的，所述高级语言编写的智能合约与所述字节码形式的智能合约具有相同或对应的暴露标识符。
可选的，所述暴露标识符标明的对象包括：收据字段和/或状态变量。
可选的，所述暴露标识符标明的对象包括下述至少之一：适用于所述智能合约中定义的所有事件的合约级对象，对应于所述智能合约中定义的至少一个事件的事件级对象。
可选的，所述交易包括交易类型字段，所述交易类型字段的取值用于标明相应的交易类型。
可选的，区块链中存储有预定义的交易类型与暴露字段之间的映射关系，所述映射关系被用于确定所述交易的交易类型对应的暴露字段。
可选的，所述交易的交易类型包括：存证类型、资产转移类型、合约创建类型、合约调用类型。
可选的，所述预设条件包括以下至少之一：相应的收据内容中包含预设内容、相应的收据内容的取值属于预设数值区间。
可选的，
所述预设条件包括所述收据数据中的所有收据字段对应的通用条件；或，
所述预设条件包括所述收据数据中的每一收据字段分别对应的专用条件。
可选的，
所述预设条件位于所述交易中；或，
所述预设条件位于所述交易对应的智能合约中，或所述交易对应的智能合约所调用的另一智能合约中；或，
所述预设条件位于***合约或链代码中。
可选的，所述存储单元64具体用于：
读取***合约的代码，所述***合约的代码中定义了与所述特殊事件函数相关的收据数据存储逻辑；
执行所述***合约的代码，以在所述智能合约包含特殊事件函数时，将对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、将所述收据数据的其余内容以密文形式存储。
可选的，所述***合约包括：记录于创世块中的预置***合约，或所述预置***合约对应的更新后***合约。
可选的，所述存储单元64具体用于：
在所述可信执行环境之外执行存储功能代码，以将所述收据数据存储至所述可信执行环境之外的外部存储空间。
可选的，第一区块链节点对所述收据数据进行加密的密钥包括：对称加密算法的密钥或非对称加密算法的密钥。
可选的，所述对称加密算法的密钥包括所述客户端提供的初始密钥；或，所述对称加密算法的密钥包括所述初始密钥与影响因子生成的衍生密钥。
可选的，所述交易由所述初始密钥进行加密，且所述初始密钥被非对称加密算法的公钥进行加密；所述解密单元62具体用于：
用所述非对称加密算法的私钥解密得到所述初始密钥，并用所述初始密钥对所述交易进行解密，以得到所述交易内容。
可选的，所述初始密钥由客户端生成；或，所述初始密钥由密钥管理服务器发送至所述客户端。
可选的，所述影响因子与所述交易相关。
可选的，所述影响因子包括：所述交易的哈希值的指定位。
在20世纪90年代，对于一个技术的改进可以很明显地区分是硬件上的改进(例如，对二极管、晶体管、开关等电路结构的改进)还是软件上的改进(对于方法流程的改进)。然而，随着技术的发展，当今的很多方法流程的改进已经可以视为硬件电路结构的直接改进。设计人员几乎都通过将改进的方法流程编程到硬件电路中来得到相应的硬件电路结构。因此，不能说一个方法流程的改进就不能用硬件实体模块来实现。例如，可编程逻辑器件(Programmable Logic Device,PLD)(例如现场可编程门阵列(Field Programmable Gate Array，FPGA))就是这样一种集成电路，其逻辑功能由用户对器件编程来确定。由设计人员自行编程来把一个数字***“集成”在一片PLD上，而不需 要请芯片制造厂商来设计和制作专用的集成电路芯片。而且，如今，取代手工地制作集成电路芯片，这种编程也多半改用“逻辑编译器(logic compiler)”软件来实现，它与程序开发撰写时所用的软件编译器相类似，而要编译之前的原始代码也得用特定的编程语言来撰写，此称之为硬件描述语言(Hardware Description Language，HDL)，而HDL也并非仅有一种，而是有许多种，如ABEL(Advanced Boolean Expression Language)、AHDL(Altera Hardware Description Language)、Confluence、CUPL(Cornell University Programming Language)、HDCal、JHDL(Java Hardware Description Language)、Lava、Lola、MyHDL、PALASM、RHDL(Ruby Hardware Description Language)等，目前最普遍使用的是VHDL(Very-High-Speed Integrated Circuit Hardware Description Language)与Verilog。本领域技术人员也应该清楚，只需要将方法流程用上述几种硬件描述语言稍作逻辑编程并编程到集成电路中，就可以很容易得到实现该逻辑方法流程的硬件电路。
控制器可以按任何适当的方式实现，例如，控制器可以采取例如微处理器或处理器以及存储可由该(微)处理器执行的计算机可读程序代码(例如软件或固件)的计算机可读介质、逻辑门、开关、专用集成电路(Application Specific Integrated Circuit，ASIC)、可编程逻辑控制器和嵌入微控制器的形式，控制器的例子包括但不限于以下微控制器：ARC 625D、Atmel AT91SAM、Microchip PIC18F26K20以及Silicone Labs C8051F320，存储器控制器还可以被实现为存储器的控制逻辑的一部分。本领域技术人员也知道，除了以纯计算机可读程序代码方式实现控制器以外，完全可以通过将方法步骤进行逻辑编程来使得控制器以逻辑门、开关、专用集成电路、可编程逻辑控制器和嵌入微控制器等的形式来实现相同功能。因此这种控制器可以被认为是一种硬件部件，而对其内包括的用于实现各种功能的装置也可以视为硬件部件内的结构。或者甚至，可以将用于实现各种功能的装置视为既可以是实现方法的软件模块又可以是硬件部件内的结构。
上述实施例阐明的***、装置、模块或单元，具体可以由计算机芯片或实体实现，或者由具有某种功能的产品来实现。一种典型的实现设备为计算机。具体的，计算机例如可以为个人计算机、膝上型计算机、蜂窝电话、相机电话、智能电话、个人数字助理、媒体播放器、导航设备、电子邮件设备、游戏控制台、平板计算机、可穿戴设备或者这些设备中的任何设备的组合。
为了描述的方便，描述以上装置时以功能分为各种单元分别描述。当然，在实 施本说明书时可以把各单元的功能在同一个或多个软件和/或硬件中实现。
本领域内的技术人员应明白，本发明的实施例可提供为方法、***、或计算机程序产品。因此，本发明可采用完全硬件实施例、完全软件实施例、或结合软件和硬件方面的实施例的形式。而且，本发明可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器、CD-ROM、光学存储器等)上实施的计算机程序产品的形式。
本发明是参照根据本发明实施例的方法、设备(***)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器，使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。
本说明书可以在由计算机执行的计算机可执行指令的一般上下文中描述，例如程序模块。一般地，程序模块包括执行特定任务或实现特定抽象数据类型的例程、程序、对象、组件、数据结构等等。也可以在分布式计算环境中实践本说明书，在这些分布式计算环境中，由通过通信网络而被连接的远程处理设备来执行任务。在分布式计算环境中，程序模块可以位于包括存储设备在内的本地和远程计算机存储介质中。
这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理设备以特定方式工作的计算机可读存储器中，使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品，该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。
这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上，使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。在一个典型的配置中，计算机包括一个或多个处理器(CPU)、输入/输出接口、网络接口和内存。
内存可能包括计算机可读介质中的非永久性存储器，随机存取存储器(RAM)和/或非易失性内存等形式，如只读存储器(ROM)或闪存(flash RAM)。内存是计算机 可读介质的示例。
计算机可读介质包括永久性和非永久性、可移动和非可移动媒体可以由任何方法或技术来实现信息存储。信息可以是计算机可读指令、数据结构、程序的模块或其他数据。计算机的存储介质的例子包括，但不限于相变内存(PRAM)、静态随机存取存储器(SRAM)、动态随机存取存储器(DRAM)、其他类型的随机存取存储器(RAM)、只读存储器(ROM)、电可擦除可编程只读存储器(EEPROM)、快闪记忆体或其他内存技术、只读光盘只读存储器(CD-ROM)、数字多功能光盘(DVD)或其他光学存储、磁盒式磁带、磁盘存储、量子存储器、基于石墨烯的存储介质或其他磁性存储设备或任何其他非传输介质，可用于存储可以被计算设备访问的信息。按照本文中的界定，计算机可读介质不包括暂存电脑可读媒体(transitory media)，如调制的数据信号和载波。
还需要说明的是，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、商品或者设备不仅包括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法、商品或者设备所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括所述要素的过程、方法、商品或者设备中还存在另外的相同要素。
上述对本说明书特定实施例进行了描述。其它实施例在所附权利要求书的范围内。在一些情况下，在权利要求书中记载的动作或步骤可以按照不同于实施例中的顺序来执行并且仍然可以实现期望的结果。另外，在附图中描绘的过程不一定要求示出的特定顺序或者连续顺序才能实现期望的结果。在某些实施方式中，多任务处理和并行处理也是可以的或者可能是有利的。
在本说明书一个或多个实施例使用的术语是仅仅出于描述特定实施例的目的，而非旨在限制本说明书一个或多个实施例。在本说明书一个或多个实施例和所附权利要求书中所使用的单数形式的“一种”、“所述”和“该”也旨在包括多数形式，除非上下文清楚地表示其他含义。还应当理解，本文中使用的术语“和/或”是指并包含一个或多个相关联的列出项目的任何或所有可能组合。
应当理解，尽管在本说明书一个或多个实施例可能采用术语第一、第二、第三等来描述各种信息，但这些信息不应限于这些术语。这些术语仅用来将同一类型的信息彼此区分开。例如，在不脱离本说明书一个或多个实施例范围的情况下，第一信息也可以被称为第二信息，类似地，第二信息也可以被称为第一信息。取决于语境，如在此所使用的词语“如果”可以被解释成为“在……时”或“当……时”或“响应于确定”。
以上所述仅为本说明书一个或多个实施例的较佳实施例而已，并不用以限制本说明书一个或多个实施例，凡在本说明书一个或多个实施例的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本说明书一个或多个实施例保护的范围之内。

Claims (35)

  1. 一种基于事件函数类型的收据存储方法，包括：
    第一区块链节点接收经过加密的对应于智能合约的交易；
    第一区块链节点在可信执行环境中解密所述交易以获得所述智能合约，所述智能合约包含特殊事件函数；
    第一区块链节点在所述可信执行环境中执行所述智能合约，得到收据数据，所述收据数据包含对应于所述特殊事件函数的日志；
    第一区块链节点存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储。
  2. 根据权利要求1所述的方法，所述至少一部分收据内容匹配于所述特殊事件函数对应的暴露日志字段。
  3. 根据权利要求2所述的方法，所述特殊事件函数中包含被标明的所述暴露日志字段；或者，所述特殊事件函数中包含被标明的加密日志字段，所述暴露日志字段为其他日志字段。
  4. 根据权利要求2所述的方法，第一区块链节点确定所述特殊事件函数对应的暴露日志字段，包括：
    第一区块链节点获取预定义的特殊事件函数与暴露日志字段之间的映射关系，或者获取预定义的特殊事件函数与加密日志字段之间的映射关系；
    第一区块链节点根据所述智能合约包含的特殊事件函数和所述映射关系，确定所述特殊事件函数对应的暴露日志字段。
  5. 根据权利要求4所述的方法，所述映射关系记录于***合约中。
  6. 根据权利要求1所述的方法，所述智能合约中的事件函数包含类型标识符，所述类型标识符用于将所述事件函数标记为特殊事件函数。
  7. 根据权利要求1所述的方法，当所述智能合约包含的事件函数位于区块链上记录的特殊函数列表中时，所述智能合约包含的事件函数被判定为特殊事件函数。
  8. 根据权利要求1所述的方法，第一区块链节点存储所述收据数据，包括：
    第一区块链节点存储所述收据数据，使交易发起方属于预设用户类型的情况下，对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储。
  9. 根据权利要求8所述的方法，第一区块链节点通过下述方式确定所述交易发起方所属的用户类型：
    第一区块链节点确定所述交易发起方对应的外部账户；
    第一区块链节点查询区块链上记录的所述外部账户对应的用户类型，以作为所述交易发起方所属的用户类型。
  10. 根据权利要求9所述的方法，所述外部账户包括记录于区块链上的用户类型字段，所述用户类型字段的取值对应于所述用户类型。
  11. 根据权利要求9所述的方法，在创建所述外部账户时，所述用户类型被配置为关联至所述外部账户，使所述用户类型与所述外部账户之间的关联关系被记录于区块链中。
  12. 根据权利要求11所述的方法，还包括：
    第一区块链节点根据管理用户发起的更改请求，更改所述外部账户对应的用户类型。
  13. 根据权利要求1所述的方法，以明文形式存储的所述至少一部分收据内容满足下述规则中至少之一：
    所述至少一部分收据内容匹配于由所述智能合约的代码所含的暴露标识符标明的对象；
    所述至少一部分收据内容对应于所述交易的交易类型对应的暴露字段；
    所述至少一部分收据内容所含的信息满足预设条件。
  14. 根据权利要求13所述的方法，第一区块链节点接收的交易对应的智能合约，包括：
    高级语言编写的智能合约；或，
    字节码形式的智能合约。
  15. 根据权利要求14所述的方法，所述高级语言编写的智能合约与所述字节码形式的智能合约具有相同或对应的暴露标识符。
  16. 根据权利要求13所述的方法，所述暴露标识符标明的对象包括：收据字段和/或状态变量。
  17. 根据权利要求13所述的方法，所述暴露标识符标明的对象包括下述至少之一：适用于所述智能合约中定义的所有事件的合约级对象，对应于所述智能合约中定义的至少一个事件的事件级对象。
  18. 根据权利要求13所述的方法，所述交易包括交易类型字段，所述交易类型字段的取值用于标明相应的交易类型。
  19. 根据权利要求13所述的方法，区块链中存储有预定义的交易类型与暴露字段 之间的映射关系，所述映射关系被用于确定所述交易的交易类型对应的暴露字段。
  20. 根据权利要求13所述的方法，所述交易的交易类型包括：存证类型、资产转移类型、合约创建类型、合约调用类型。
  21. 根据权利要求13所述的方法，所述预设条件包括以下至少之一：相应的收据内容中包含预设内容、相应的收据内容的取值属于预设数值区间。
  22. 根据权利要求13所述的方法，
    所述预设条件包括所述收据数据中的所有收据字段对应的通用条件；或，
    所述预设条件包括所述收据数据中的每一收据字段分别对应的专用条件。
  23. 根据权利要求13所述的方法，
    所述预设条件位于所述交易中；或，
    所述预设条件位于所述交易对应的智能合约中，或所述交易对应的智能合约所调用的另一智能合约中；或，
    所述预设条件位于***合约或链代码中。
  24. 根据权利要求1所述的方法，第一区块链节点存储所述收据数据，包括：
    第一区块链节点读取***合约的代码，所述***合约的代码中定义了与所述特殊事件函数相关的收据数据存储逻辑；
    第一区块链节点执行所述***合约的代码，以在所述智能合约包含特殊事件函数时，将对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、将所述收据数据的其余内容以密文形式存储。
  25. 根据权利要求24所述的方法，所述***合约包括：记录于创世块中的预置***合约，或所述预置***合约对应的更新后***合约。
  26. 根据权利要求1所述的方法，第一区块链节点存储所述收据数据，包括：
    第一区块链节点在所述可信执行环境之外执行存储功能代码，以将所述收据数据存储至所述可信执行环境之外的外部存储空间。
  27. 根据权利要求1所述的方法，第一区块链节点对所述收据数据进行加密的密钥包括：对称加密算法的密钥或非对称加密算法的密钥。
  28. 根据权利要求27所述的方法，所述对称加密算法的密钥包括所述客户端提供的初始密钥；或，所述对称加密算法的密钥包括所述初始密钥与影响因子生成的衍生密钥。
  29. 根据权利要求28所述的方法，所述交易由所述初始密钥进行加密，且所述初始密钥被非对称加密算法的公钥进行加密；第一区块链节点在可信执行环境中解密所述 交易，包括：
    第一区块链节点用所述非对称加密算法的私钥解密得到所述初始密钥，并用所述初始密钥对所述交易进行解密，以得到所述交易内容。
  30. 根据权利要求28所述的方法，所述初始密钥由客户端生成；或，所述初始密钥由密钥管理服务器发送至所述客户端。
  31. 根据权利要求28所述的方法，所述影响因子与所述交易相关。
  32. 根据权利要求31所述的方法，所述影响因子包括：所述交易的哈希值的指定位。
  33. 一种基于事件函数类型的收据存储节点，包括：
    接收单元，接收经过加密的对应于智能合约的交易；
    解密单元，在可信执行环境中解密所述交易以获得所述智能合约，所述智能合约包含特殊事件函数；
    执行单元，在所述可信执行环境中执行所述智能合约，得到收据数据，所述收据数据包含对应于所述特殊事件函数的日志；
    存储单元，存储所述收据数据，使对应于所述特殊事件函数的日志中的至少一部分收据内容以明文形式存储、所述收据数据的其余内容以密文形式存储。
  34. 一种电子设备，包括：
    处理器；
    用于存储处理器可执行指令的存储器；
    其中，所述处理器通过运行所述可执行指令以实现如权利要求1-32中任一项所述的方法。
  35. 一种计算机可读存储介质，其上存储有计算机指令，该指令被处理器执行时实现如权利要求1-32中任一项所述方法的步骤。
PCT/CN2020/089385 2019-05-20 2020-05-09 基于事件函数类型的收据存储方法和节点 WO2020233424A1 (zh)

Applications Claiming Priority (28)

Application Number Priority Date Filing Date Title
CN201910419924.8A CN110247895B (zh) 2019-05-20 2019-05-20 收据存储方法、节点、设备及存储介质
CN201910419959.1 2019-05-20
CN201910420663.1A CN110245946B (zh) 2019-05-20 2019-05-20 结合代码标注与多类型维度的收据存储方法和节点
CN201910419907.4A CN110263088B (zh) 2019-05-20 2019-05-20 结合代码标注与事件类型的有条件的收据存储方法和节点
CN201910419898.9 2019-05-20
CN201910419908.9A CN110223172B (zh) 2019-05-20 2019-05-20 有条件的结合代码标注与类型维度的收据存储方法和节点
CN201910419930.3A CN110263090B (zh) 2019-05-20 2019-05-20 多类型维度的收据存储方法和节点
CN201910419943.0 2019-05-20
CN201910419907.4 2019-05-20
CN201910420666.5 2019-05-20
CN201910419925.2 2019-05-20
CN201910420663.1 2019-05-20
CN201910419924.8 2019-05-20
CN201910419898.9A CN110263087B (zh) 2019-05-20 2019-05-20 基于多维度信息且具有条件限制的收据存储方法和节点
CN201910419752.4A CN110264194B (zh) 2019-05-20 2019-05-20 基于事件函数类型的收据存储方法和节点
CN201910419897.4 2019-05-20
CN201910419930.3 2019-05-20
CN201910419925.2A CN110263089B (zh) 2019-05-20 2019-05-20 结合交易与事件类型的条件限制的收据存储方法和节点
CN201910419908.9 2019-05-20
CN201910420689.6A CN110276684B (zh) 2019-05-20 2019-05-20 结合交易类型和事件函数类型的收据存储方法和节点
CN201910419752.4 2019-05-20
CN201910419158.5 2019-05-20
CN201910419959.1A CN110264197B (zh) 2019-05-20 2019-05-20 结合事件函数类型和判断条件的收据存储方法和节点
CN201910419158.5A CN110263086B (zh) 2019-05-20 2019-05-20 结合用户类型与事件函数类型的收据存储方法和节点
CN201910420689.6 2019-05-20
CN201910420666.5A CN110263091B (zh) 2019-05-20 2019-05-20 结合代码标注与用户、事件类型的收据存储方法和节点
CN201910419943.0A CN110245504B (zh) 2019-05-20 2019-05-20 结合多类型维度的条件限制的收据存储方法和节点
CN201910419897.4A CN110278193B (zh) 2019-05-20 2019-05-20 结合代码标注与交易、事件类型的收据存储方法和节点

Publications (1)

Publication Number Publication Date
WO2020233424A1 true WO2020233424A1 (zh) 2020-11-26

Family

ID=73459096

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/089385 WO2020233424A1 (zh) 2019-05-20 2020-05-09 基于事件函数类型的收据存储方法和节点

Country Status (1)

Country Link
WO (1) WO2020233424A1 (zh)

Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106559211A (zh) * 2016-11-22 2017-04-05 中国电子科技集团公司第三十研究所 一种区块链中隐私保护智能合约方法
CN107294709A (zh) * 2017-06-27 2017-10-24 阿里巴巴集团控股有限公司 一种区块链数据处理方法、装置及***
CN107342858A (zh) * 2017-07-05 2017-11-10 武汉凤链科技有限公司 一种基于可信环境的智能合约保护方法和***
US20180343114A1 (en) * 2015-11-24 2018-11-29 Adi BEN-ARI A system and method for blockchain smart contract data privacy
CN109033855A (zh) * 2018-07-18 2018-12-18 腾讯科技（深圳）有限公司 一种基于区块链的数据传输方法、装置及存储介质
CN109493020A (zh) * 2018-11-08 2019-03-19 众安信息技术服务有限公司 基于区块链的安全交易方法和装置
CN109766722A (zh) * 2019-01-22 2019-05-17 苏州同济区块链研究院有限公司 一种区块链中构建智能合约的方法及其***
CN110223172A (zh) * 2019-05-20 2019-09-10 阿里巴巴集团控股有限公司 有条件的结合代码标注与类型维度的收据存储方法和节点
CN110245504A (zh) * 2019-05-20 2019-09-17 阿里巴巴集团控股有限公司 结合多类型维度的条件限制的收据存储方法和节点
CN110245946A (zh) * 2019-05-20 2019-09-17 阿里巴巴集团控股有限公司 结合代码标注与多类型维度的收据存储方法和节点
CN110247895A (zh) * 2019-05-20 2019-09-17 阿里巴巴集团控股有限公司 结合代码标注与事件函数类型的收据存储方法和节点
CN110263090A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 多类型维度的收据存储方法和节点
CN110263089A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合交易与事件类型的条件限制的收据存储方法和节点
CN110263086A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合用户类型与事件函数类型的收据存储方法和节点
CN110264194A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 基于事件函数类型的收据存储方法和节点
CN110264197A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合事件函数类型和判断条件的收据存储方法和节点
CN110263087A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 基于多维度信息且具有条件限制的收据存储方法和节点
CN110263088A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合代码标注与事件类型的有条件的收据存储方法和节点
CN110263091A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合代码标注与用户、事件类型的收据存储方法和节点
CN110278193A (zh) * 2019-05-20 2019-09-24 阿里巴巴集团控股有限公司 结合代码标注与交易、事件类型的收据存储方法和节点
CN110276684A (zh) * 2019-05-20 2019-09-24 阿里巴巴集团控股有限公司 结合交易类型和事件函数类型的收据存储方法和节点

Patent Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180343114A1 (en) * 2015-11-24 2018-11-29 Adi BEN-ARI A system and method for blockchain smart contract data privacy
CN106559211A (zh) * 2016-11-22 2017-04-05 中国电子科技集团公司第三十研究所 一种区块链中隐私保护智能合约方法
CN107294709A (zh) * 2017-06-27 2017-10-24 阿里巴巴集团控股有限公司 一种区块链数据处理方法、装置及***
CN107342858A (zh) * 2017-07-05 2017-11-10 武汉凤链科技有限公司 一种基于可信环境的智能合约保护方法和***
CN109033855A (zh) * 2018-07-18 2018-12-18 腾讯科技（深圳）有限公司 一种基于区块链的数据传输方法、装置及存储介质
CN109493020A (zh) * 2018-11-08 2019-03-19 众安信息技术服务有限公司 基于区块链的安全交易方法和装置
CN109766722A (zh) * 2019-01-22 2019-05-17 苏州同济区块链研究院有限公司 一种区块链中构建智能合约的方法及其***
CN110247895A (zh) * 2019-05-20 2019-09-17 阿里巴巴集团控股有限公司 结合代码标注与事件函数类型的收据存储方法和节点
CN110264194A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 基于事件函数类型的收据存储方法和节点
CN110245946A (zh) * 2019-05-20 2019-09-17 阿里巴巴集团控股有限公司 结合代码标注与多类型维度的收据存储方法和节点
CN110223172A (zh) * 2019-05-20 2019-09-10 阿里巴巴集团控股有限公司 有条件的结合代码标注与类型维度的收据存储方法和节点
CN110263090A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 多类型维度的收据存储方法和节点
CN110263089A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合交易与事件类型的条件限制的收据存储方法和节点
CN110263086A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合用户类型与事件函数类型的收据存储方法和节点
CN110245504A (zh) * 2019-05-20 2019-09-17 阿里巴巴集团控股有限公司 结合多类型维度的条件限制的收据存储方法和节点
CN110264197A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合事件函数类型和判断条件的收据存储方法和节点
CN110263087A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 基于多维度信息且具有条件限制的收据存储方法和节点
CN110263088A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合代码标注与事件类型的有条件的收据存储方法和节点
CN110263091A (zh) * 2019-05-20 2019-09-20 阿里巴巴集团控股有限公司 结合代码标注与用户、事件类型的收据存储方法和节点
CN110278193A (zh) * 2019-05-20 2019-09-24 阿里巴巴集团控股有限公司 结合代码标注与交易、事件类型的收据存储方法和节点
CN110276684A (zh) * 2019-05-20 2019-09-24 阿里巴巴集团控股有限公司 结合交易类型和事件函数类型的收据存储方法和节点

Similar Documents

Publication Publication Date Title
WO2020233644A1 (zh) 有条件的结合代码标注与类型维度的收据存储方法和节点
WO2020233616A1 (zh) 结合代码标注与交易、用户类型的收据存储方法和节点
WO2020233642A1 (zh) 有条件的结合代码标注与类型维度的收据存储方法和节点
WO2020233643A1 (zh) 基于多维度信息且具有条件限制的收据存储方法和节点
WO2020233612A1 (zh) 结合代码标注与交易、事件类型的收据存储方法和节点
WO2020233638A1 (zh) 结合代码标注与交易类型的收据存储方法和节点
WO2020233613A1 (zh) 结合代码标注与交易类型的有条件的收据存储方法和节点
WO2020233622A1 (zh) 结合代码标注与多类型维度的收据存储方法和节点
WO2020233609A1 (zh) 结合代码标注与用户类型的有条件的收据存储方法和节点
WO2020233623A1 (zh) 结合交易类型和判断条件的收据存储方法和节点
WO2020233610A1 (zh) 结合代码标注与用户、事件类型的收据存储方法和节点
WO2020233626A1 (zh) 结合交易与用户类型的条件限制的收据存储方法和节点
WO2020233637A1 (zh) 结合代码标注与用户类型的收据存储方法和节点
WO2020233635A1 (zh) 结合多类型维度的条件限制的收据存储方法和节点
WO2020233640A1 (zh) 结合代码标注与判断条件的收据存储方法和节点
WO2020233614A1 (zh) 结合代码标注与事件类型的有条件的收据存储方法和节点
WO2020233615A1 (zh) 结合用户类型与事件函数类型的收据存储方法和节点
WO2020233628A1 (zh) 结合事件函数类型和判断条件的收据存储方法和节点
WO2020233630A1 (zh) 基于用户类型的收据存储方法和节点
WO2020233639A1 (zh) 结合代码标注与事件函数类型的收据存储方法和节点
WO2020233619A1 (zh) 结合用户类型与交易类型的收据存储方法和节点
WO2020233625A1 (zh) 结合用户类型和判断条件的收据存储方法和节点
WO2020233624A1 (zh) 结合交易类型和事件函数类型的收据存储方法和节点
WO2020233627A1 (zh) 多类型维度的收据存储方法和节点
WO2020233629A1 (zh) 基于代码标注的对象级收据存储方法和节点

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20808963

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20808963

Country of ref document: EP

Kind code of ref document: A1