NL2026376B1 - Public chain-based transaction method and blockchain system - Google Patents

Abstract

This application provides a public chain-based transaction method and blockchain system. According to the method, a transaction initiating chain first initiates a query transaction to a public chain; subsequently, the public chain queries a transaction target chain that accesses a public chain network, and returns information about the transaction target chain that satisfies information about a service type; the transaction initiating chain further initiates a service transaction to the public chain based on a transaction manner and a transaction condition that are required by the transaction target chain; the public chain transmits the service transaction to the transaction target chain; the transaction target chain returns service content to the public chain based on the received service transaction after the transaction condition is verified to be qualified; and finally, the public chain further transmits the service content to the transaction initiating chain, to complete a cross-chain transaction. In this method, querying and transmitting the service transaction by using the public chain network enables the transaction initiating chain to obtain the service content of the transaction target chain, thus completing a cross-chain transaction between different chain networks. In this way, an applications scope of a blockchain- based transaction method is improved.

Description

P128204NL00 Title: Public chain-based transaction method and blockchain system

FIELD OF THE INVENTION This application relates to the technical field of blockchain, and in particular, to a public chain-based transaction method and blockchain system.

BACKGROUND OF THE INVENTION A blockchain technology is decentralized system thinking, and can create a relatively objective non-repudiation digital environment in a well- known manner. The blockchain technology may make sure that network information cannot be modified once being published. For example, if a transaction occurs in a blockchain network, a node in the blockchain network may record content of the transaction in a generated block, and broadcast block data in the whole network; and other nodes in the network store the block data synchronously or asynchronously, to form a blockchain that cannot be modified. The transaction should be understood in a broad sense, does not refer to a conventional "commodity sale" or "objective exchange", but refers to a type of or certain data operation content or operation result in the blockchain network. For example, if a blockchain node A in the network initiates a query request a for performance of a communications device with certain model, the query request a is a transaction for a blockchain node B that is responsible for a query service. Similarly, sending, by the node B, a queried performance table b of the communications device with this model to the node A is also a transaction. As transaction information, information A and a and information B and b may be written into a data block of the blockchain.

Existing blockchain-based transaction methods may be limited within a same blockchain network only, that is, most are for transactions between nodes in the blockchain network. Moreover, for each type of blockchain network, a unique virtual currency serves as a transaction medium. For example, a bitcoin-based transaction method is suitable for a bitcoin blockchain network only, and uses bitcoin as a virtual currency for transactions; and a Ethereum-based transaction method is suitable for a Ethereum blockchain network only, and uses ETH as a virtual currency for transactions. With development of the blockchain network technology, more blockchain networks, such as an industry chain, a federated chain, and a private chain are established, to implement actual applications in a particular industry. In view of the above, the existing blockchain networks are independent from each other, and no effective mechanisms are unified between different chains to communicate and interact. However, due to different application scenarios, each type of blockchain may provide different capability sets. Endogeneity of the blockchain network decides that interworking cannot be performed between capability sets provided by different chains. Thus, data and application islanding effects are caused, and applications of the blockchain-based transaction methods are limited.

SUMMARY OF THE INVENTION This application provides a public chain-based transaction method and blockchain system, to resolve a problem that a conventional transaction method does not support a cross-chain transaction, and limits applications of a blockchain-based transaction method. According to one aspect, this application provides a public chain- based transaction method, including: initiating, by a transaction initiating chain, a query transaction including information about a service type to a public chain;

querying, by the public chain based on the information about the service type in the query transaction, a transaction target chain that accesses a public chain network; returning, by the public chain, information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain, where the information about the transaction target chain includes an address of the target chain, a transaction manner, and a transaction condition; initiating, by the transaction initiating chain, a service transaction to the public chain based on the transaction manner and the transaction condition; transmitting, by the public chain, the service transaction to the transaction target chain; verifying, by the transaction target chain, the transaction condition, and returning service content to the public chain based on the received service transaction after the transaction condition is verified to be qualified; and transmitting, by the public chain, the service content to the transaction initiating chain.

Optionally, the step of the initiating, by a transaction initiating chain, a query transaction including information about a service type to a public chain includes: generating, by a transaction node in the transaction initiating chain, a transaction request based on actual transaction information; broadcasting, by the transaction node, the transaction request in the transaction initiating chain, to form blockchain accounting conforming to the transaction initiating chain; verifying, by an accounting node, the transaction request and adding the same into block data; and broadcasting, by the accounting node, the block data to other nodes, and initiating the query transaction to a maintenance node in the public chain, where smart contracts provided by the public chain include a smart contract and a public smart contract that are created by the public chain.

Optionally, before the step of the initiating, by a transaction initiating chain, a query transaction including information about a service type to a public chain, the method further includes: initiating, by the public chain, contract verification information to a blockcham network of the accessed public chain network, to verify whether the accessed blockchain network supports a smart contract provided by the public chain; and setting, by the public chain, a contract determining label for the accessed blockchain network based on a verification result of whether the smart contract is supported, including: setting a contract determining label for a corresponding interface node of the accessed blockchain network; or setting a contract determining label for an address of the accessed blockchain network.

Optionally, after the step of the returning, by the public chain, information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain, if both the transaction initiating chain and the transaction target chain support an interface specification agreed by the public chain, in the method, the service content is further returned to the transaction initiating chain according to the following steps: directly initiating, by the transaction initiating chain, the service transaction to the transaction target chain based on the transaction manner and the transaction condition; verifying, by the transaction target chain, the transaction condition, and returning the service content to the transaction initiating chain based on the received service transaction after the transaction condition is verified to be qualified; and synchronizing, by the transaction initiating chain and the 5 transaction target chain, transaction digest to the public chain after the transaction 1s completed.

Optionally, the step of the initiating, by a transaction initiating chain, a query transaction including information about a service type to a public chain further includes: determining, by the public chain, whether the transaction initiating chain supports a smart contract; if the transaction initiating chain does not support the smart contract, creating, by the public chain, a smart contract for the transaction initiating chain, or configuring a public smart contract for the transaction initiating chain; and determining, by the public chain based on the smart contract or the public smart contract, corresponding addresses of the transaction initiating chain and the transaction target chain.

Optionally, the transaction condition includes a transaction token amount designated by the transaction target chain, and before the step of initiating, by the transaction initiating chain, the service transaction to the public chain based on the transaction condition, the following are further included: determining whether an amount of tokens owned by the transaction initiating chain meets the transaction token amount designated by the transaction target chain; if the amount of tokens owned by the transaction initiating chain meets the transaction token amount designated by the transaction target chain, allowing the transaction initiating chain to initiate the service transaction to the public chain; and if the amount of tokens owned by the transaction initiating chain does not meet the transaction token amount designated by the transaction target chain, sending prompt information to the transaction initiating chain, and continuing to query, based on the service type, other transaction target chains that access the public chain network.

Optionally, the step of initiating, by the transaction initiating chain, the service transaction to the public chain based on the transaction condition includes: creating, by the transaction initiating chain, a transferring transaction on the public chain, to trigger execution of a contract, where the transferring transaction includes a designated amount of transaction tokens paid to the transaction target chain.

Optionally, the step of the transmitting, by the public chain, the service transaction to the transaction target chain includes: locking the transferring transaction by the public chain, and initiating a request transaction to the transaction target chain based on the transferring transaction; providing a returned transaction result for the public chain by the transaction target chain based on a transaction request; verifying the returned transaction result by the public chain, and releasing a locking state of the transferring transaction if the returned transaction is consistent with the transferring transaction; and transferring, by the public chain, the tokens paid by the transaction initiating chain to the transaction target chain, and forwarding the service content to the transaction initiating chain.

Optionally, after querying, by the public chain, the transaction target chain that accesses the public chain network, the method further includes: determining, by the public chain, whether the transaction initiating chain and the transaction target chain support transacting directly by using tokens of the public chain; if the transaction initiating chain and/or the transaction target chain does not support transacting directly by using the tokens of the public chain, converting the tokens in a parallel chain corresponding to the transaction initiating chain and/or the transaction target chain; and initiating the service transaction to the public chain by the parallel chain corresponding to the transaction initiating chain, and returning the service content to the public chain by the parallel chain corresponding to the transaction target chain.

According to another aspect, this application further provides a public chain-based blockchain system, including a transaction initiating chain, a public chain, and a transaction target chain, where the transaction initiating chain establishes a network connection to the transaction target chain by using the public chain; the transaction initiating chain is configured to: initiate a query transaction including information about a service type to the public chain; and initiate a service transaction to the public chain based on a transaction condition of the transaction target chain; the public chain is configured to: query, based on the service type in the query transaction, the transaction target chain that accesses a public chain network; return information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain, where the information about the transaction target chain includes an address of the target chain, a transaction manner, and the transaction condition; and transmit the service transaction to the transaction target chain, and transmit service content to the transaction initiating chain; and the transaction target chain is configured to: verify the transaction condition, and return the service content to the public chain based on the received service transaction after the transaction condition is verified to be qualified. It may be learned from the foregoing technical solutions that according to this method, in actual applications, the transaction initiating chain first initiates the query transaction to the public chain; subsequently, the public chain queries, based on the information about the service type in the query transaction, the transaction target chain that accesses the public chain network, so that the public chain is enabled to return the information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain; the transaction initiating chain further initiates the service transaction to the public chain based on the transaction manner and the transaction condition that are required by the transaction target chain; the public chain transmits the service transaction to the transaction target chain; the transaction target chain returns the service content to the public chain based on the received service transaction after the transaction condition is verified to be qualified; and finally, the public chain further transmits the service content to the transaction initiating chain, to complete a cross-chain transaction. In this method, querying and transmitting the service transaction by using the public chain network enables the transaction initiating chain to obtain the service content of the transaction target chain, thus completing a cross- chain transaction between different chain networks. In this way, an applications scope of a blockchain-based transaction method is improved.

BRIEF DESCRIPTION OF THE DRAWINGS To more clearly describe the technical solutions of this application, the accompanying drawings to be used in the embodiments are briefly illustrated below. Obviously, persons of ordinary skills in the art can also derive other accompanying drawings according to these accompanying drawings without an effective effort.

FIG. 1 is a schematic flowchart of a public chain-based transaction method according to this application; FIG. 2 is a schematic flowchart of initiating, by a transaction initiating chain, a query transaction to a public chain according to this application; FIG. 3 is a schematic flowchart of determining whether a transaction initiating chain supports a smart contract according to this application; FIG. 4 is a schematic flowchart of determining whether a transaction initiating chain and a transaction target chain support a transaction of using tokens of a public chain according to this application; FIG. 5 is a schematic flowchart of determining whether an amount of tokens of the transaction initiating chain satisfies requirements according to this application; FIG. 6 is a schematic flowchart of a transaction when the transaction is locked by a public chain according to this application; FIG. 7 is a schematic flowchart of a transaction when a transaction initiating chain and a transaction target chain support an interface specification agreed by a public chain according to this application; and FIG. 8 is a schematic structural diagram of a public chain-based blockchain system according to this application.

DETAILED DESCRIPTION OF THE EMBODIMENTS Embodiments are described below in detail, and examples thereof are shown in the accompanying drawings. When the descriptions below relate to the accompanying drawings, unless otherwise stated, same numbers in different accompanying drawings indicate same or similar elements. Implementations described in the following embodiments do not represent all implementations consistent with this application. Merely examples of a system and a method that are described in detail in the claims and in accordance with some aspects of this application are provided.

In technical solutions provided in this application, a blockchain network refers to a peer-to-peer (P2P) network that has a decentralized application architecture.

The blockchain network can perform distributed storage, public consensus, digital encryption, transaction accounting, and verifications.

In other words, the blockchain network is a transaction platform that covers a distributed technology, the cryptography, a P2P network architecture, and various consensus algorithms that may be applied.

A blockchain or blockchain information refers to accounting information generated based on transaction information when a transaction occurs in the blockchain network.

That is, a plurality of specific transactions form a block, and a plurality of blocks form an ordered blockchain.

The blockchain network includes nodes that establish peer-to- peer network connections with each other.

Each node is configured with a corresponding consensus mechanism, such as a smart contract; and has a sufficient computing capability, to perform a transaction verification process and an accounting process.

Interface specifications conforming to an agreed standard are provided on the nodes, so that more nodes or other types of blockchain networks are accessed through the interface specifications.

In this application, referred public chain, transaction initiating chain, transaction target chain, and parallel chain all refer to different blockchain networks that conform to a blockchain technology.

In this application, unless otherwise stated, the public chain, the transaction initiating chain, the transaction target chain, and the parallel chain all refer to corresponding networks, that is, a public chain network, a transaction initiating chain network, a transaction target chain network,

and a parallel chain network.

In the technical solutions provided in this application, the public chain network serves as a basic platform configured on a whole network, and a node interface thereof accesses a plurality of blockchain networks, such as an industry chain, a federated chain, and a private chain that are established based on an interface specification of the public chain.

Each blockchain network may serve as a development platform, and provides corresponding services for interior of the network.

A standard interface manner is defined and specified for the public chain, thus facilitating a network connection to other blockchains, such as the transaction initiating chain and the transaction target chain.

In this application, the public chain is capable of supporting cross-chain brokering, and further is capable of providing decentralized applications and a smart contract.

The transaction initiating chain and the transaction target chain refer to blockchains accessing the public chain network.

To be specific, in this application, the public chain provides a basic platform, and the transaction initiating chain and the transaction target chain, serving as accessing networks, have respective functions and services.

The transaction initiating chain and the transaction target chain may be blockchain networks that are established based on standards and interface specifications of the public chain network.

In other words, the transaction initiating chain and the transaction target chain may directly perform communication and service interworking with the public chain network.

The transaction initiating chain and the transaction target chain may also be networks that are independent from each other, such as bitcoins or Ethereum in the existing blockchain network, or an industry chain and a federated chain developed in some industries, or even a private chain established for satisfying certain service requirement.

These existing blockchain, industry chain, federated chain, and private chain generally cannot directly transact with each other or even cannot transact with the public chain network. Therefore, in this application, the public chain may be connected to another network by using the parallel chain. The parallel chain may be composed of some nodes in the public chain network; and by using the parallel chain, bridging may be performed between the public chain and another network to which transactions cannot be directly performed. In this application, for a network to which transactions cannot be directly performed, each blockchain network corresponds to a parallel chain. The parallel chain is configured to have complete functions corresponding to the blockchain network, can synchronously convert the transaction in the blockchain network, and transmit the same to the public chain network. Therefore, in the technical solutions provided in this application, the parallel chain may be determined as an image of the corresponding blockchain network. Moreover, for ease of description, the corresponding blockchain network is referred to as a parent chain. In this application, the parallel chain is composed of some nodes in the public chain network, and these nodes are also nodes in the parent chain, so as to transmit transaction information.

On the basis of the foregoing components, in actual applications, the public chain may provide cross-chain relay, to complete a transaction verification, data proof, asset transfer, implementations of the smart contract, and other work. The public chain unifies external interface specifications, so that other blockchain networks may quickly access the public chain network. The public chain further provides basic blockchain platform capabilities, that is, quickly completes solution deployment and verifications, to complete a distributed storage process and an accounting process in the public chain network. In addition, as a basic platform, the public chain may further provide a public development function, so as to complete collaborative development and deployment of a plurality of smart contracts of the parallel chains at one time.

In addition to recording own blockchain information, the public chain may further be configured to store information digest, that is, transaction digest, of a corresponding cross-chain transaction. Relevant content of the cross-chain transaction is recorded through formatted transaction data. Meanwhile, to occupy less distributed storage space on the public chain, when recording some information, the public chain may further record information about a third-party blockchain through a particular compression algorithm. For example, block data formed and stored in the public chain may include the following content: a block identifier (such as a sequence number, a time stamp, a block hash value, and a previous block hash value), block attribution (that is, a block generator), other block information (such as a random value, a difficulty value, and additional information), block weight, information digest (such as a transaction tree, a state tree, a receipt tree, and a data tree), transaction fees, rewards, sizes, and the like.

To implement a cross-chain transaction, this application provides a public chain-based transaction method. As shown in FIG. 1, the transaction method includes the following steps.

S1: A transaction initiating chain initiates a query transaction including information about a service type to a public chain.

In a technical solution provided in this application, the transaction initiating chain determines, according to own service requirements, the service type required by the transaction initiating chain, and sends the service type to a public chain network by means of a query transaction. In this application, because the transaction initiating chain 1s also a blockchain network accessing the public chain, the query transaction initiated herein may be initiated by a node in the transaction initiating chain. After a transaction node initiates the query transaction, a transaction initiating chain network first determines a service transaction, to determine whether the service transaction may be completed within the transaction initiating chain network.

If the current service transaction may be completed within the transaction initiating chain network, there is no need to initiate the query transaction to the public chain network. In other words, within the transaction initiating chain network, the transaction node transacts with another node that may provide the corresponding service type. This transaction process may form blockchain information within the transaction initiating chain network, and perform distributed storage, verification, and other processes within the transaction initiating chain network. If the current service transaction cannot be completed within the transaction initiating chain network, a corresponding query transaction may be generated by using a smart contract in the transaction initiating chain, and the query transaction is initiated by the public chain. Obviously, the initiated query transaction necessarily includes the service type required in the service transaction. In addition, for a third-party blockchain that cannot directly transact with the public chain, the query transaction may be transmitted to the public chain by using a parallel chain, to initiate the query transaction.

For example, there are five blockchain networks, which respectively are blockchain networks A-E, that access a public cham network P. A network B includes 100 nodes which are respectively marked as B00-B99. In actual applications, if a node B25 in the network B needs to exchange for tokens Ta in equal value by using 100 tokens Tb, the node B25 services as a transaction node, creates a query transaction according to requirements, and forms block data. The service type included in the query transaction is token exchange. The node B25 may first broadcast the query transaction in the network B, that 1s, broadcast the query transaction to other nodes, such as B24 and B26. In one aspect, other nodes in the network B store the block data of the query transaction in a distributed manner, thus completing accounting. In another aspect, it may be determined that whether there is another node, in the network B, that meets a transaction request of the node B25, that is, whether other nodes may exchange for the tokens Ta from the node B25.

If other nodes in the network B cannot complete the token exchange, the query transaction needs to be broadcasted to a node in the public chain network P, so that the node in the public chain network P determines, based on the query transaction, whether networks A, C, D, and E may exchange for the tokens Ta from the node B25.

Further, as shown in FIG. 2, initiating, by the transaction initiating chain, the query transaction including the information about the service type to the public chain may further include the following steps.

S101: A transaction node in the transaction initiating chain generates transaction information based on an actual transaction.

S102: The transaction node broadcasts the transaction information in the transaction initiating chain, to form blockchain accounting conforming to the transaction initiating chain.

S103: An accounting node verifies the transaction and adds the same into block data.

S104: The accounting node broadcasts the block data to other nodes in the transaction initiating chain, and meanwhile, initiates the query transaction to a maintenance node in the public chain, where smart contracts provided by the public chain include a smart contract and a public smart contract that are created by the public chain.

It may be learned from the foregoing steps that after the transaction node generates the transaction, the transaction information may be broadcasted in the transaction initiating chain. According to an accounting rule, the transaction initiating chain writes the transaction information into block data and stores the same in a distributed manner, to form blockchain accounting data conforming to the transaction initiating chain. The block data records information about actual transactions initiated by the transaction node, such as: a service type, an amount of the transactions, a transaction initiator, a transaction target, and a hash value. After the broadcasting in the transaction initiating chain, the transaction node further adds the smart contract and the information about the service type into the block data.

Still using the foregoing token exchanging service as an example, after initiating the query transaction, the transaction node B25 generates block data including the token exchanging service, and further broadcasts the transaction information of the query transaction in the network B. A specific broadcasting manner may be determined according to a broadcasting manner in the network B. For example, the transaction node B25 may first broadcast the block data to adjacent nodes B24 and B26. The adjacent nodes B24 and B26 verify the transaction, to determine whether the transaction is legal, and store the block data to form a blockchain. Subsequently, the adjacent nodes B24 and B26 broadcast the block data to respectively adjacent nodes, so that all nodes in the network B may verify and store the block data, to form integral blockchain data conforming to an accounting specification in the network B.

In this embodiment, the smart contracts provided by the public chain include the smart contract and the public smart contract that are created by the public chain. Information about the smart contract is used for transactions with the public chain, so as to initiate the query transaction and the subsequent service transaction. The information about the service type includes necessary service description information or service code information stored in the public chain network, and may be used to initiate the query transaction. Subsequently, the block data added with the smart contract and the information about the service type is broadcasted to the maintenance node in the public chain, so as to initiate the query transaction. A maintenance node in the public chain network may be a node configured to provide an interface for the transaction initiating chain, or may be another designated node. For ease of initiating the query transaction, a condition may be met by using a calculation capability, and a node relatively close to the transaction initiating chain serves as the maintenance node, to increase a broadcasting speed of the block data.

It should be noted that in technical solutions provided in this application, the service transaction includes specific transaction content, may be a virtual currency exchanging transaction, such as exchanging tokens in the transaction initiating chain for tokens in equal value in the transaction target chain; or may be purchasing a service by using a virtual currency, such as a query service for the network or a reporting service. The query transaction is a special transaction, and a transaction form thereof is same to that of a normal transaction. However, a specific transaction manner needs to be specially agreed, for example, a transaction carrying information about a smart contract of the query transaction, or a transaction of which an amount of tokens agreed to be transferred is 0.

In some embodiments of this application, before the step of initiating the query transaction by the transaction initiating chain, the smart contract may further be verified for the transaction initiating chain by using the public chain, to determine whether the transaction initiating chain supports the smart contract provided by the public chain. In other words, contract verification information is initiated by the public chain to a blockchain network of the accessed public chain network, to verify whether the accessed blockchain network supports the smart contract provided by the public chain. In actual applications, each blockchain network accessing the public chain may serve as the transaction initiating chain. Therefore, in this embodiment, after a blockchain network accesses the public chain, a smart contract may be verified for the blockchain network.

After the smart contract is verified, the public chain may set a contract determining label for the accessed blockchain network based on a verification result of whether the smart contract is supported. Specifically, a contract determining label is set for a corresponding interface node of the accessed blockchain network; or a contract determining label is set for an address of the accessed blockchain network. According to the manner of setting the contract determining label for the corresponding interface node of the accessed blockchain network, a determining label set for the interface node may be extracted when the corresponding blockchain network serves as the transaction initiating chain, so as to determine whether the current transaction initiating chain supports the smart contract. Moreover, according to the manner of setting the contract determining label for the address of the accessed blockchain network, whether the corresponding transaction initiating chain supports the smart contract may also be determined by extracting the address of the transaction initiating chain.

In this embodiment, for a transaction initiating chain that supports the smart contract, the query transaction may be directly initiated to the public chain by using the smart contract, without participation of the parallel chain. For a transaction initiating chain that does not support the smart contract, the smart contract may be configured for the transaction initiating chain by using the public chain, or the query transaction is transmitted from the transaction node to the public chain through bridging of the parallel chain. The parallel chain has been configured with a smart contract. Therefore, as shown in FIG. 3, before initiating the query transaction to the public chain by the transaction initiating chain, the transaction method may further include the following.

S105: The public chain determines whether the transaction initiating chain supports a smart contract.

S106: If the transaction initiating chain does not support the smart contract, the public chain creates a smart contract for the transaction initiating chain, or configures a public smart contract for the transaction initiating chain.

S107: The public chain determines, based on the smart contract or the public smart contract, corresponding addresses of the transaction initiating chain and a transaction target chain.

In this embodiment, the public chain extracts the contract determining label on the transaction initiating chain, that is, analyzes the contract determining label, to determine whether the transaction initiating chain supports the smart contract. Alternatively, a contract determining transaction in a particular format may be initiated to the transaction initiating chain by using the smart contract on the public chain, and a contract determining result returned by the transaction initiating chain is analyzed. If the transaction initiating chain may return content conforming to a specification of the smart contract, it is determined that the transaction initiating chain supports the smart contract. If the transaction initiating chain cannot return the content conforming to the specification of the smart contract, or does not make a response, it 15 determined that the transaction initiating chain does not support the smart contract.

For the transaction initiating chain that supports the smart contract, a subsequent transaction step may be performed. To be specific, the transaction initiating chain initiates the query transaction to the public chain by using the smart contract. Moreover, for the transaction initiating chain that does not support the smart contract, the smart contract may be configured for the transaction initiating chain by using the public chain, or a public contract may be selected for the transaction initiating chain by using the public chain, and the selected public contract is configured for the transaction initiating chain. In this embodiment, the public contract may be a contract that 1s widely applied and is used in the blockchain network, or may be a contract specification agreed in a current industry field. After the smart contract or the public smart contract is configured for the transaction initiating chain, the public chain may further determine address information of the transaction initiating chain and the transaction target chain, that is, determine the transaction initiating chain and the transaction target chain, so as to implement a subsequent transaction.

S2: The public chain queries, based on the information about the service type in the query transaction, the transaction target chain that accesses a public chain network.

In technical solutions provided in this application, after receiving the query transaction initiated by the transaction initiating chain, the public chain extracts the information about the service type in the query transaction, and queries in the public chain network based on the information about the service type, to find a blockchain network that can provide a service corresponding to the information about the service type to serve as the transaction target chain. Similarly, a network that serves as the transaction target chain also includes a plurality of nodes. In other words, the transaction target chain is composed of a plurality of nodes. Therefore, in the transaction target chain, there may be one or more nodes that can provide services. In view of the above, in the technical solutions provided in this application, a result queried by the public chain may be a transaction target chain, or may be a node that is in the transaction target chain and can provide a service. In the technical solutions provided in this application, it is preferred that the result queried by the public chain is a form of a transaction target chain, so as to quickly determine the transaction target chain, thus avoiding a case in which the transaction target chain does not support to be queried by the public chain.

In this embodiment, querying the transaction target chain in the public chain network by the public chain may be completed by using a smart contract configured in the public chain, or may be completed by using a decentralized application in the public chain network. A specific query process may be querying in information that is stored in the public chain network and is about an accessed blockchain network. According to such a query manner, the public chain is required to communicate by using an accessing node when a blockchain network is accessed, to obtain information registered by the accessed blockchain network. The registered information may include: a service type that can be provided, a type of tokens that can be exchanged, a transaction manner, a transaction condition, and the like. A program in the public chain correspondingly stores these registered information and corresponding network addresses, and broadcasts the same in a whole network.

The query process may also be completed according to the following manner. To be specific, after receiving the query transaction, the public chain broadcasts a transaction for providing a service in the whole network once. After receiving the transaction for providing a service, the blockchain network accessing the public chain may correspondingly reply for the transaction. Replied information may include a transaction condition and a transaction manner. The public chain selects a blockchain network that replies the earliest as the transaction target chain, or determines a most suitable (a required token amount is the smallest, or circulation of transaction tokens is the best) transaction target chain for the transaction condition.

Further, to settle the transaction and complete an accounting process, as shown in FIG. 4, after the public chain queries the transaction target chain that accesses the public chain network, the method further includes the following.

S201: The public chain determines whether the transaction initiating chain and the transaction target chain support transacting directly by using tokens of the public chain.

S202: If the transaction initiating chain and/or the transaction target chain does not support transacting directly by using the tokens of the public chain, convert the tokens in a parallel chain corresponding to the transaction initiating chain and/or the transaction target chain.

S203: The parallel chain corresponding to the transaction initiating chain initiates a service transaction to the public chain, and the parallel chain corresponding to the transaction target chain returns the service content to the public chain.

In this embodiment, after the public chain queries the transaction target chain, whether the transaction initiating chain and the transaction target chain support transacting directly by using the tokens of the public chain may be determined based on information stored in the public chain. If the transaction initiating chain and the transaction target chain may transact directly by using the tokens of the public chain, the public chain is enabled to perform an accounting process and to verify a transaction settlement. If the transaction initiating chain and/or the transaction target chain does not support transacting directly by using the tokens of the public chain, the tokens may be converted in the parallel chain corresponding to the transaction initiating chain and/or the transaction target chain. In other words, according to exchange rates between the public chain and the transaction initiating chain and the transaction target chain, tokens paid by the transaction initiating chain are first exchanged as tokens in equal value of the public chain, and then the public chain transmits the tokens thereof to the transaction target chain. Moreover, during a subsequent transaction process, the service transaction is completed by the parallel chain.

S3: The public chain returns information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain, where the information about the transaction target chain includes an address of the target chain, a transaction manner, and a transaction condition.

After querying the transaction target chain, the public chain may obtain the address information, the transaction manner, the transaction condition, and other information of the transaction target chain. Obviously, the public chain may obtain the foregoing information from the registered information stored in the public chain, or the information may be provided by the transaction target chain by means of forwarding the query transaction to the transaction target chain. To improve the query efficiency, in this application, it is preferred to obtain the foregoing information by means of the registered information stored in the public chain. After obtaining the information about the transaction target chain, the public cham may send the obtained information about the target chain to the transaction initiating chain, so that the transaction initiating chain determines, based on the information about the transaction target chain, whether to perform a transaction with the transaction target chain.

In the technical solutions provided in this application, the address of the target chain is an address that is of the transaction target chain and is registered in the public chain network, or an address of a node providing an interface when the transaction target chain accesses the public chain. The transaction manner is transaction time set by the transaction target chain, a format (template) of blockchain information, a type of tokens supporting transactions, or the like. The transaction condition may not only include a designated amount of tokens to be charged for providing a service,

but may also include requirements on qualification of the transaction initiating chain, such as requirements on an amount of owned tokens, or scoring for a reputation of the transaction initiating chain.

Further, to obtain a more suitable transaction target chain, some additional information, for example, a type of transaction tokens that may be provided, a required service specification, a service providing qualification of the transaction target chain, an upper limit of the transaction tokens, may be further carried in the query transaction.

For example, when the query transaction initiated by the transaction node B25 does not has a node that may provide the token exchanging service in the network B, the query transaction may be broadcasted to maintenance nodes P01-P99 in the public chain network P by using a connection node BP (or an interface node) between the network B and the public chain network P.

The maintenance node in the public chain also needs to verify the query transaction and store the query transaction in a distributed manner, and to determine, based on the query transaction, whether other blockchain networks A, C, D, and E that access the public chain network P may provide the token exchanging service.

If it is queried that there is a network A that may satisfy the token exchanging service in the other blockchain networks, address information of the network A in the public chain network P 1s obtained, such as an IP address of a connection node AP, and a transaction condition that is of the network A and 1s registered in the public chain network P, that is, a transaction condition required for exchanging tokens Tb for tokens Ta, such as an exchange rate between the tokens Tb and the tokens Ta, or an exchange qualification owned by a counterparty required by the network A.

A service node in the public chain P creates a query result based on the address of the network A and the transaction condition of the network A, and returns the query result to the transaction node B25.

S4: The transaction initiating chain initiates the service transaction to the public chain based on the transaction manner and the transaction condition.

In a technical solution provided in this application, after receiving the information about the transaction target chain returned by the public chain, the transaction initiating chain may analyze the information about the transaction target chain, to extract the transaction manner and the transaction condition in the information about the transaction target chain.

For the transaction manner, the transaction initiating chain may determine whether to support the transaction manner provided by the transaction target chain.

Moreover, for the transaction condition, the transaction initiating chain may automatically or manually determine whether the transaction condition proposed by the transaction target chain can be accepted.

If the transaction condition can be accepted and the corresponding transaction manner is supported, the transaction initiating chain may initiate a service transaction meeting the transaction condition to the public chain according to the designated transaction manner.

The step of initiating, by the transaction initiating chain, the service transaction to the public chain based on the transaction condition includes: creating, by the transaction initiating chain, a transferring transaction on the public chain, to trigger execution of a contract, where the transferring transaction includes a designated amount of transaction tokens paid to the transaction target chain.

For example, after the maintenance node in the public chain network P returns the query result to the transaction node B25, the transaction node B25 verifies the transaction condition and the transaction manner in the returned query result.

In one aspect, whether the transaction satisfies a requirement, that is, whether the transaction may satisfy a request for a token exchanging service of the B25, is determined.

In another aspect, whether the transaction condition can be accepted, for example, whether a token exchanging rate required by a transaction target chain A is acceptable may be determined. The foregoing verification process may be automatically determined by using the node B25, or whether to accept the transaction condition may be actively selected. Verification to the returned query result may further include whether the transaction node B25 can transact according to a transaction manner designated by the transaction target chain A. If the transaction node B25 accepts the transaction condition and may transact according to the transaction manner designated by the transaction target chain A, the transaction node B25 initiates a formal service transaction, that is, transfers 100 tokens Tb to the public chain network P. It should be noted that in this cross-chain transaction, the maintenance node in the public chain network takes corresponding query and storage operations, and further participates in other operations, such as transmission, value transformation, and accounting, in a subsequent transaction process. Therefore, when the transaction node B25 initiates the formal service transaction to the public chain, a particular amount of public-chain tokens further need to be transferred to the public chain network to serve as awards of the maintenance node in the public chain.

Further, as shown in FIG. 5, the transaction condition includes the transaction token amount designated by the transaction target chain, and before the step of initiating, by the transaction initiating chain, the service transaction to the public chain based on the transaction condition, the following are further included.

S401: Determine whether an amount of tokens owned by the transaction initiating chain meets a transaction token amount designated by the transaction target chain.

S402: If the amount of tokens owned by the transaction initiating chain meets the transaction token amount designated by the transaction target chain, allow the transaction initiating chain to initiate the service transaction to the public chain.

S403: If the amount of tokens owned by the transaction initiating chain does not meet the transaction token amount designated by the transaction target chain, send prompt information to the transaction initiating chain, and continue to query, based on the service type, other transaction target chains that access the public chain network.

In this embodiment, if the transaction condition is the transaction token amount designated by the transaction target chain, the public chain may determine balance of designated tokens owned by the transaction initiating chain, to determine whether the transaction initiating chain may satisfy requirements of the transaction condition designated by the transaction target chain.

For a case in which the transaction condition is met, the transaction initiating chain is allowed to initiate the service transaction to the public chain.

For a case in which the transaction condition is not met, the prompt information may be sent to the transaction initiating chain to notify the transaction initiating chain; moreover, other transaction target chains that access the public chain network may be kept being queried based on the service type.

The foregoing processes are repeated, until the case in which the transaction condition is met 1s queried.

For example, the transaction condition required by the transaction target chain A is that an amount of tokens Tb owned by the transaction node that serves as a transaction initiator is not less than 100. Therefore, before the formal service transaction is initiated, the amount of the tokens Th owned by the transaction node may be determined by using the public chain network.

If the amount of the tokens Th owned by the transaction node is 53, it 1s determined that the transaction condition is not met.

In this case, the public chain network sends prompt information, such as "Your balance of tokens Tb is insufficient, transaction cannot be completed" or "not less than 100 tokens Tb are required for the transaction, you need another 47 tokens to complete the transaction”, to the transaction node B25.

S5: The public chain transmits the service transaction to the transaction target chain.

In a technical solution provided in this application, the service transaction sent to the public chain by the transaction initiating chain may not be processed in the public chain, and the service transaction is merely transmitted to the transaction target chain by the public chain network. The public chain may extract the address information of the transaction target chain in the service transaction, obtain a position of the transaction target chain, and then send the service transaction to the transaction target chain based on the address of the transaction target chain.

For example, after receiving the service transaction initiated by the transaction node B25, the maintenance node in the public chain network P verifies the 100 tokens Tb that are transferred by the transaction node, forms block data conforming to a transaction form of the public chain for the service transaction, broadcasts the formed block data in the public chain network, and then transfers the 100 tokens Tb to a Tb account corresponding to the network A. Because transmission of the service transaction is completed based on the public chain, to achieve non-repudiation transaction effects, when the public chain transmits the service transaction, a distributed storage needs to be performed in the public chain network. In other words, accounting needs to be performed in the public chain network. Therefore, when the public chain transmits the service transaction, this is also a transaction occurring in the public chain network. In actual applications,

different types of tokens circulate in different blockchain networks, but generally the different types of tokens cannot be directly used for transactions. Therefore, in the technical solution provided in this application, during a process in which the public chain transmits the service transaction to the transaction target chain, the tokens paid by the transaction initiating chain may be first locked, and then public-chain tokens in equal value are transferred to the transaction target chain, to trigger the transaction target chain to return the service content.

In other words, in some embodiments of this application, as shown in FIG. 6, the step of transmitting, by the public chain, the service transaction to the transaction target chain includes the following.

S501: The public chain locks the transferring transaction, and Initiates a request transaction to the transaction target chain based on the transferring transaction.

S502: The transaction target chain provides a returned transaction result for the public chain based on a transaction request.

S503: The public chain verifies the returned transaction result, and releases a locking state of the transferring transaction if the returned transaction result is consistent with the transferring transaction.

S504: The public chain transfers the tokens paid by the transaction initiating chain to the transaction target chain, and forwards the service content to the transaction initiating chain.

In this embodiment, the public chain first locks a transferring transaction, that is, temporarily locks the tokens paid by the transaction initiating chain, and then initiates the request transaction to the transaction target chain based on the transferring transaction. The request transaction is used to trigger the transaction target chain to return the transaction, and the public chain subsequently verifies content of the returned transaction. If the returned transaction is consistent with the transferring transaction, a locking state of the transferring transaction is released, so that the public chain transfers the tokens paid by the transaction initiating chain to the transaction target chain, and transmits the service content to the transaction initiating chain. By locking the transferring transaction by the public chain, transaction content may be verified in the public chain network, to determine whether transaction specifications are actually met, thus ensuring transaction rights of both parties of the transaction.

S6: The transaction target chain verifies the transaction condition, and returns the service content to the public chain based on the received service transaction after the transaction condition is verified to be qualified. In a technical solution provided in this application, after receiving the service transaction transmitted by the public chain, the transaction target chain first verifies the transaction condition, to determine whether the service transaction meets the transaction condition, for example, whether an amount of tokens paid by the service transaction meets an amount of tokens required by the transaction target chain, or whether the transaction initiating chain has a transaction qualification required by the transaction target chain. If the transaction target chain verifies that the transaction condition is qualified, the corresponding service content is returned based on the received service transaction. In other words, a corresponding service is provided for the transaction initiating chain. The service content may be specific service content included in a returned transaction, such as a data retrieval report, or another type of exchanged tokens with a designated amount. Moreover, for the service content needs to be maintained in a long term, the returned service content may include corresponding network accessing information, a verification code, an account number, and the like. For the service content needs to be maintained in a long term, the public chain may not directly participate in a subsequent data transmission process, but only transmits the corresponding network accessing information, the verification code, the account number, and other information to the transaction initiating chain when returning the service content, and stores the returned service content in the public chain in a distributed manner, to complete an accounting process. S7: The public chain transmits the service content to the transaction initiating chain. After receiving the service content returned by the transaction target chain, the public chain transmits the service content to the transaction initiating chain by means of relaying. After the public chain forwards the service content to the transaction initiating chain, it is represented that the transaction is completed. For example, in the public chain network P, after 100 tokens Th are transferred to the Tb account corresponding to the network A, the public chain network extracts tokens Ta in equal value from a Ta account corresponding to the network A after the verification of the transaction target chain passes. If an exchange rate is 2:1, 50 tokens Ta are extracted to be transferred to an account corresponding to the network B, to complete the final service transaction.

In some embodiments of this application, as shown in FIG. 7, after the step of the returning, by the public chain, the information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain, if both the transaction initiating chain and the transaction target chain support an interface specification agreed by the public chain, in the method, the service content may be further returned to the transaction initiating chain according to the following steps.

S8: The transaction initiating chain directly initiates the service transaction to the transaction target chain based on the transaction manner and the transaction condition.

S9: The transaction target chain verifies the transaction condition, and returns the service content to the transaction initiating chain based on the received service transaction after the transaction condition is verified to be qualified.

In some blockchain network systems, because the entire network is a peer-to-peer network, theoretically a network connection may be established between any two nodes. Therefore, communication may be directly performed between different blockchain network that access the public chain. Such a blockchain network supports the interface specification agreed by the public chain. To be specific, if both the transaction initiating chain and the transaction target chain support the interface specification agreed by the public chain, after the public chain returns the information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain, the transaction initiating chain may directly extract an address of the transaction target chain 1n the information about the transaction target chain, and directly initiates the service transaction to the transaction target chain based on the address.

After receiving the service transaction initiated by the transaction initiating chain, the transaction target chain verifies the transaction condition. Specific verification content is consistent with the content in the foregoing embodiment. After the transaction condition is verified to be qualified, the transaction target chain further directly returns the transaction content to the transaction initiating chain based on the received service transaction, to complete the final transaction.

For the foregoing case, to ensure the accounting process of the transaction between the transaction initiating chain and the transaction target chain, when the transaction initiating chain initiates the service transaction, distributed accounting may be performed in the transaction initiating chain, and the stored block data or digest of the block data is sent to the public chain network to be stored in a distributed manner. Moreover, when the transaction target chain returns the service content, distributed accounting may be performed in the transaction target chain, and meanwhile, the stored block data or the digest of the block data is also sent to the public chain network to be stored in a distributed manner. Moreover, after the transaction target chain sends stored blockchain data or data digest to the public chain, the public chain may further compare, regarding address information in the block data, consistency of the block data sent by the transaction initiating chain and the transaction target chain, to determine legality and the like of the transaction.

This embodiment differs from the foregoing embodiments in that the public chain network is merely responsible for the corresponding query transaction. To be specific, after the transaction initiating chain initiates the query transaction, the public chain network returns the address information of the transaction target chain to the transaction node B25 after the transaction target chain is queried based on the query transaction. Based on the information about the address of the target chain, the transaction node B25 directly initiates the service transaction to the transaction target chain A, that is, transfers 100 tokens Tb to the transaction target chain A. After receiving the 100 tokens Th, a service node in the transaction target chain A further transfers 50 tokens Ta to the transaction node B25, so as to directly complete the transaction. Obviously, to avoid a transaction error, block data formed when the transaction node B25 transfers 100 tokens Tb to the transaction target chain A is not only broadcasted in the network B, but also needs to be broadcasted in the public chain network. Similarly, when the service node in the transaction target chain A transfers 50 tokens Ta to the transaction node B25, the block data also needs to be synchronously or asynchronously broadcasted in the transaction target chain network A and the public chain network P.

It should be noted that in the technical solutions provided in this application, for ease of description, that the transaction node B25 transfers 100 tokens Tb to the transaction target chain A, and the service node in the transaction target chain A transfers 50 tokens Ta to the transaction node B25 refer to a circulation direction of the token or the transaction result, and do not mean that a token entity is really transferred from one chain to another chain.

In actual applications, both parties of a transaction may have corresponding accounts in two networks.

Moreover, the transferring transaction is merely transferring tokens to the corresponding account.

To be specific, the 100 Th are exchanged in the network B, and the 50 Ta are exchanged in the network A.

Only content describing the cross-chain transaction, such as the transaction information and accounting data are transmitted by using the public chain.

On the basis of the foregoing transaction method, this application further provides a public chain-based blockchain system.

As shown in FIG. 8, the system includes a transaction initiating chain, a public chain, and a transaction target chain, where the transaction initiating chain establishes a network connection to the transaction target chain by using the public chain.

The transaction initiating chain refers to a blockchain network that serves as a transaction initiator, and the transaction target chain refers to a blockchain network that serves as a transaction target.

To complete a cross-chain transaction, the transaction initiating chain is configured to perform the following program step: initiate a query transaction including information about a service type to the public chain.

To be specific, at beginning of the cross-chain transaction, the transaction initiating chain initiate the query transaction to the public chain, so that the public chain queries the transaction target chain in a public chain network.

The transaction initiating chain is also configured to initiate a service transaction to the public chain based on a transaction condition of the transaction target chain. To be specific, after the public chain returns information about the transaction target chain that satisfies the information about the service type, the service transaction is initiated to the public chain.

The public chain is configured to: query, based on the service type in the query transaction, the transaction target chain that accesses the public chain network; return the information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain, where the information about the transaction target chain includes an address of the target chain, a transaction manner, and the transaction condition; and transmit the service transaction to the transaction target chain, and transmit service content to the transaction initiating chain.

The transaction target chain is configured to: verify the transaction condition, and return the service content to the public chain based on the received service transaction after the transaction condition is verified to be qualified. In addition, the transaction target chain may further provide the address information, the transaction manner, and the transaction condition thereof for the public chain after the public chain queries the transaction target chain.

In a technical solution provided in this application, both the transaction initiating chain and the transaction target chain refer to some of a plurality of blockchain networks that access the public chain network.

Therefore, any one of the plurality of blockchain networks that access the public chain network may serve as the transaction initiating chain, provided that the blockchain network has a sufficient amount of tokens for triggering a transaction. Similarly, each blockchain network may also serve as the transaction target chain, provided that the blockchain network supports transacting with the external, and can provide specific service content. In other words, in the technical solutions provided in this application, the transaction initiating chain and the transaction target chain are merely for ease of description, and do not limit the blockchain network.

It should be noted that in this embodiment, solutions are described by using the service content in token exchange as an example. Obviously, transaction processes of different forms of service content are same to a transaction process of the token exchange. When the transaction node initiates the service transaction, after the transaction node transfers a designated amount of tokens to the public chain (or the transaction target chain), the transaction target chain returns specific transaction content based on the service transaction, for example, returns a query result about performance of a communication device of a certain model.

It may be learned from the foregoing technical solutions that this application provides a public chain-based transaction method and blockchain network. According to this method, in actual applications, the transaction initiating chain first initiates the query transaction to the public chain; subsequently, the public chain queries, based on the information about the service type in the query transaction, the transaction target chain that accesses the public chain network, so that the public chain is enabled to return the information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain; the transaction initiating chain further initiates the service transaction to the public chain based on the transaction manner and the transaction condition that are required by the transaction target chain; the public chain transmits the service transaction to the transaction target chain; the transaction target chain returns the service content to the public chain based on the received service transaction after the transaction condition is verified to be qualified; and finally, the public chain further transmits the service content to the transaction initiating chain, to complete a cross-chain transaction.

In this method, querying and transmitting the service transaction by using the public chain network enables the transaction initiating chain to obtain the service content of the transaction target chain, thus completing a cross-chain transaction between different chain networks.

In this way, an applications scope of a blockchain-based transaction method is improved.

For similar parts between the embodiments provided in this application, reference may be made to each other.

The specific implementations described above are merely some examples under a general concept of this application, and do not constitute any limitation to the protection scope of this application.

For a person skilled in the art, any other implementations derived according to the solutions of this application without an effective effort all fall within the protection scope of this application.

Claims (10)

ConclusiesConclusions 1. Op openbare keten gebaseerde transactiewerkwijze, omvattende: het initiëren, door middel van een transactie-initiërende keten, van een querytransactie welke informatie omvat over een servicetype naar een openbare keten; het queryen, door de openbare keten op basis van de informatie over de servicetype in de querytransactie, een transactie doelketen welke toegang heeft tot een openbaar ketennetwerk; het teruggeven, door de openbare keten, van informatie over de transactie doelketen welke voldoet aan de informatie over het servicetype aan de transactie- initiërende keten, waarbij de informatie over de transactie doelketen een adres van de doelketen, een transactiewijze en een transactievoorwaarde omvat; het initiëren, door de transactie-initiërende keten, van een servicetransactie naar de openbare keten op basis van de transactiewijze en de transactievoorwaarde; het verzenden, door de openbare keten, van de servicetransactie naar de transactie doelketen; het verifiëren, door de transactie doelketen, van de transactievoorwaarde, en het teruggeven van service-inhoud aan de openbare keten op basis van de ontvangen servicetransactie nadat is geverifieerd welke de transactievoorwaarde gekwalificeerd is; en het verzenden, door de openbare keten, van de service-inhoud naar de transactie-initiërende keten.A public chain transaction method, comprising: initiating, by means of a transaction initiating chain, a query transaction including information about a service type to a public chain; querying, by the public chain based on the service type information in the query transaction, a transaction target chain having access to a public chain network; returning, by the public chain, transaction target chain information that satisfies the service type information to the transaction initiating chain, the transaction target chain information including a target chain address, a transaction mode, and a transaction condition; initiating, by the transaction initiating chain, a service transaction to the public chain based on the transaction mode and the transaction condition; sending, through the public chain, the service transaction to the target transaction chain; verifying, by the transaction target chain, the transaction condition, and returning service content to the public chain based on the received service transaction after verifying which the transaction condition is qualified; and transmitting, through the public chain, the service content to the transaction initiating chain. 2. Transactiewerkwijze volgens conclusie 1, waarbij de stap van het initiéren, door een transactie-initiérende keten, van een querytransactie omvattende informatie over een servicetype naar een openbare keten, omvat: het genereren, door een transactieknooppunt in de transactie-initiërende keten, van transactie-informatie gebaseerd op een daadwerkelijke transactie;The transaction method of claim 1, wherein the step of initiating, by a transaction initiating chain, a query transaction including information about a service type to a public chain comprises: generating, by a transaction node in the transaction initiating chain, transaction information based on an actual transaction; het uitzenden, door het transactieknooppunt, van de transactie-informatie in de transactie-initiërende keten, om blockchain-accounting te vormen welke overeenstemt met de transactie-initiërende keten; het verifiëren, door een boekhoudknooppunt, van de transactie en deze toevoegen aan blokgegevens; en het uitzenden, door het boekhoudknooppunt, van de blokgegevens naar andere knooppunten in de transactie-initiërende keten, en ondertussen, het initiëren van de querytransactie naar een onderhoudsknooppunt in de openbare keten, waarbij slimme contracten welke door de openbare keten worden verstrekt een slim contract en een openbaar slim contract welke worden gecreëerd door de openbare keten omvatten.transmitting, by the transaction node, the transaction information in the transaction initiating chain to form blockchain accounting corresponding to the transaction initiating chain; verifying, by an accounting node, the transaction and appending it to block data; and broadcasting, by the accounting node, the block data to other nodes in the transaction initiating chain, and meanwhile, initiating the query transaction to a maintenance node in the public chain, wherein smart contracts provided by the public chain are a smart contract and a public smart contract created by the public chain. 3. Transactiewerkwijze volgens conclusie 1, waarbij voorafgaand aan de stap van het initiëren, door een transactie-initiërende keten, een querytransactie omvattende informatie over een servicetype naar een openbare keten, de werkwijze verder omvat: het initiëren, door de openbare keten, van contractverificatie-informatie naar een blockchain-netwerk van het waartoe toegang verkregen openbare ketennetwerk, om te verifiëren of het waartoe toegang verkregen blockchain- netwerk een slim contract ondersteunt welke door de openbare keten wordt geleverd; en het instellen, door de openbare keten, van een contracthepalingslabel voor het geraadpleegde blockchain-netwerk op basis van een verificatieresultaat of het slimme contract wordt ondersteund, omvattende: het instellen van een contractbepalingslabel voor een corresponderend interfaceknooppunt van het benaderde blockchain-netwerk; of het instellen van een contractbepalend label voor een adres van het geraadpleegde blockchain-netwerk.The transaction method of claim 1, wherein prior to the step of initiating, through a transaction initiating chain, a query transaction including information about a service type to a public chain, the method further comprises: initiating, by the public chain, contract verification information to a blockchain network of the accessed public chain network, to verify whether the accessed blockchain network supports a smart contract provided by the public chain; and setting, by the public chain, a contract determination tag for the accessed blockchain network based on a verification result whether the smart contract is supported, comprising: setting a contract determination tag for a corresponding interface node of the accessed blockchain network; or setting a contract-determining label for an address of the consulted blockchain network. 4. Transactiewerkwijze volgens conclusie 1, waarbij na de stap van het teruggeven, door de openbare keten, van informatie over de transactie doelketen welke voldoet aan de informatie over het servicetype aan de transactie-initiërende keten, indien zowel de transactie-initiërende keten als de transactie doelketen een interfacespecificatie overeengekomen door de openbare keten ondersteunen, in de werkwijze de service-inhoud verder wordt teruggestuurd naar de transactie- initiérende keten volgens de volgende stappen: het direct initiéren, door de transactie-initiérende keten, de servicetransactie naar de transactie doelketen op basis van de transactiewijze en de transactievoorwaarde; het verifiëren, door de transactie doelketen, van de transactievoorwaarde en het teruggeven van de service-inhoud naar de transactie-initiërende keten op basis van de ontvangen servicetransactie nadat de transactievoorwaarde is geverifieerd gekwalificeerd te zijn; en het synchroniseren, door de transactie-initiërende keten en de transactie doelketen, van corresponderende transactie hashinformatie naar de openbare keten nadat de transactie is voltooid.The transaction method of claim 1, wherein after the step of returning, by the public chain, information about the transaction target chain that satisfies the information about the service type to the transaction initiating chain, if both the transaction initiating chain and the transaction target chain supporting an interface specification agreed upon by the public chain, in the method the service content is further returned to the transaction initiating chain according to the following steps: initiating directly, through the transaction initiating chain, the service transaction to the transaction target chain on basis of the transaction method and the transaction condition; verifying, by the transaction target chain, the transaction condition and returning the service content to the transaction initiating chain based on the received service transaction after the transaction condition is verified to be qualified; and synchronizing, by the transaction initiating chain and the transaction target chain, corresponding transaction hash information to the public chain after the transaction is completed. 5. Transactiewerkwijze volgens conclusie 1, waarbij de stap van het initiëren, door een transactie-initiërende keten, van een querytransactie omvattende informatie over een servicetype naar een openbare keten verder omvat: het bepalen, door de openbare keten, of de transactie initiërende keten een slim contract ondersteunt; als de transactie-initiërende keten het slimme contract niet ondersteunt, het creëren, door de openbare keten, van een slim contract voor de transactie- initiërende keten, of het configureren van een openbaar slim contract voor de transactie-initiërende keten; en het bepalen, door de openbare keten op basis van het slimme contract of het openbare slimme contract, van corresponderende adressen van de transactie- initiërende keten en de transactie doelketen.The transaction method of claim 1, wherein the step of initiating, by a transaction initiating chain, a query transaction including information about a service type to a public chain further comprises: determining, by the public chain, whether the transaction initiating chain has a smart contract supports; if the transaction initiating chain does not support the smart contract, creating, by the public chain, a smart contract for the transaction initiating chain, or configuring a public smart contract for the transaction initiating chain; and determining, by the public chain based on the smart contract or the public smart contract, corresponding addresses of the transaction initiating chain and the transaction target chain. 6. Transactiewerkwijze volgens conclusie 1, waarbij de transactievoorwaarde een transactietokenaantal omvat welke wordt aangeduid door de transactie doelketen, en vóór de stap van het initiëren, door de transactie- initiërende keten, van de servicetransactie naar de openbare keten op basis van de transactievoorwaarde, de volgende verder zijn omvat:The transaction method of claim 1, wherein the transaction condition includes a transaction token number indicated by the transaction target chain, and before the step of initiating, by the transaction initiating chain, the service transaction to the public chain based on the transaction condition, the following further are included: het bepalen of een aantal tokens welke eigendom is van de transactie- initiérende keten overeenkomt met het transactietokenaantal welke is aangegeven door de transactie doelketen; als het aantal tokens welke eigendom is van de transactie-initiérende keten overeenkomt met de transactietokenaantal aangewezen door de transactie doelketen, het toelaten dat de transactie-initiërende keten de servicetransactie naar de openbare keten initieert; en als het aantal tokens welke eigendom is van de transactie-initiërende keten niet overeenkomt met het transactietokenaantal welke is aangegeven door de transactie doelketen, het zenden van promptinformatie naar de transactie- initiërende keten, en het doorgaan met het queryen, op basis van het servicetype, van andere transactie doelketens welke toegang hebben tot het openbare ketennetwerk.determining whether a number of tokens owned by the transaction initiating chain matches the transaction token number indicated by the transaction target chain; if the number of tokens owned by the transaction initiating chain matches the transaction token number designated by the transaction target chain, allowing the transaction initiating chain to initiate the service transaction to the public chain; and if the number of tokens owned by the transaction initiating chain does not match the transaction token number indicated by the transaction target chain, sending prompt information to the transaction initiating chain, and continuing the query, based on the service type , from other transaction target chains that have access to the public chain network. 7. Transactiewerkwijze volgens conclusie 1, waarbij de stap van het initiëren, door de transactie-initiërende keten, van de servicetransactie naar de openbare keten op basis van de transactievoorwaarde, omvat: het creëren, door de transactie-initiërende keten, van een overdrachtstransactie op de openbare keten, om de uitvoering van een contract te activeren, waarbij de overdrachtstransactie een bepaald aantal transactietokens omvat, betaald aan de transactie doelketen.The transaction method of claim 1, wherein the step of initiating, by the transaction initiating chain, the service transaction to the public chain based on the transaction condition comprises: creating, by the transaction initiating chain, a transfer transaction on the public chain, to trigger the execution of a contract, the transfer transaction comprising a certain number of transaction tokens paid to the transaction target chain. 8. Transactiewerkwijze volgens conclusie 7, waarbij de stap van het verzenden, door de openbare keten, van de servicetransactie naar de transactie doelketen omvat: het vergrendelen van de overdrachtstransactie door de openbare keten, en het initiëren van een verzoektransactie naar de transactie doelketen op basis van de overdrachtstransactie; het verschaffen van een teruggegeven transactieresultaat voor de openbare keten door de transactie doelketen op basis van een transactieverzoek; het verifiëren van het teruggegeven transactieresultaat door de openbare keten en het vrijgeven van een vergrendelingsstatus van de overdrachtstransactie als de teruggegeven transactie consistent is met de overdrachtstransactie; en het overdragen, door de openbare keten, van de tokens welke zijn betaald door de transactie-initiérende keten naar de transactie doelketen, en het doorsturen van de service-inhoud naar de transactie-initiérende keten.The transaction method of claim 7, wherein the step of transmitting, by the public chain, the service transaction to the transaction target chain comprises: locking the transfer transaction through the public chain, and initiating a request transaction to the transaction target chain based on of the transfer transaction; providing a returned transaction result for the public chain by the transaction target chain based on a transaction request; verifying the returned transaction result by the public chain and releasing a lock status of the transfer transaction if the returned transaction is consistent with the transfer transaction; and transferring, by the public chain, the tokens paid by the transaction initiating chain to the transaction target chain, and forwarding the service content to the transaction initiating chain. 9. Transactiewerkwijze volgens conclusie 1, waarbij na het queryen, door de openbare keten, de transactie doelketen welke toegang heeft tot het openbare ketennetwerk, de werkwijze verder omvat: het bepalen, door de openbare keten, of de transactie-initiërende keten en de transactie doelketen het rechtstreeks handelen door gebruik te maken van tokens van de openbare keten ondersteunen; als de transactie-initiërende keten en/of de transactie doelketen het rechtstreeks handelen door de tokens van de openbare keten te gebruiken niet ondersteunt, het omzetten van de tokens in een parallelle keten corresponderend met de transactie-initiërende keten en/of de transactie doelketen; en het initiëren van de servicetransactie naar de openbare keten door de parallelle keten welke overeenkomt met de transactie-mitiërende keten, en het teruggeven van de service-inhoud aan de openbare keten door de parallelle keten welke overeenkomt met de transactie doelketen.The transaction method of claim 1, wherein after querying, by the public chain, the transaction target chain accessing the public chain network, the method further comprises: determining, by the public chain, whether the transaction initiating chain and the transaction target chain support direct trading using public chain tokens; if the transaction initiating chain and/or the transaction target chain does not support trading directly by using the tokens of the public chain, converting the tokens into a parallel chain corresponding to the transaction initiating chain and/or the transaction target chain; and initiating the service transaction to the public chain by the parallel chain corresponding to the transaction-mitigating chain, and returning the service content to the public chain by the parallel chain corresponding to the transaction target chain. 10. Een op een openbare keten gebaseerd blockchain-systeem, welke een transactie-initiërende keten, een openbare keten en een transactie doelketen omvat, waarbij de transactie-initiërende keten een netwerkverbinding tot stand brengt met de transactie doelketen door gebruik te maken van de openbare keten; waarbij de transactie-initiërende keten is geconfigureerd om: een querytransactie te initiëren welke informatie omvat over een servicetype naar de openbare keten; en een servicetransactie te initiëren naar de openbare keten op basis van een transactievoorwaarde van de transactie doelketen; waarbij de openbare keten is geconfigureerd om: op basis van het servicetype in de querytransactie, de transactie doelketen welke toegang heeft tot. een openbare keten netwerk te queryen; informatie over de transactie doelketen welke voldoet aan de informatie over het servicetype naar de transactie-initiërende keten terug te geven, waarbij de informatie over de transactie doelketen een adres van de doelketen, een transactiewijze en de transactievoorwaarde omvat; en de servicetransactie naar de transactie doelketen te zenden, en service-inhoud naar de transactie-initiërende keten te zenden; en waarbij de transactie doelketen is geconfigureerd om: de transactievoorwaarde te verifiëren, en de service-inhoud terug te geven aan de openbare keten op basis van de ontvangen servicetransactie nadat de transactievoorwaarde is geverifieerd gekwalificeerd te zijn.10. A public chain blockchain system comprising a transaction initiating chain, a public chain and a transaction target chain, wherein the transaction initiating chain establishes a network connection to the transaction target chain by using the public chain chain; wherein the transaction initiating chain is configured to: initiate a query transaction that includes information about a service type to the public chain; and initiate a service transaction to the public chain based on a transaction condition of the transaction target chain; where the public chain is configured to: based on the service type in the query transaction, the target transaction chain to access. query a public chain network; return transaction target chain information that satisfies the service type information to the transaction initiating chain, the transaction target chain information including an address of the target chain, a transaction mode, and the transaction condition; and send the service transaction to the transaction target chain, and send service content to the transaction initiating chain; and wherein the transaction target chain is configured to: verify the transaction condition, and return the service content to the public chain based on the received service transaction after the transaction condition is verified to be qualified.