KR101663250B1 - Secret chatting apparatus and method using deniable encryption - Google Patents
Secret chatting apparatus and method using deniable encryption Download PDFInfo
- Publication number
- KR101663250B1 KR101663250B1 KR1020150095701A KR20150095701A KR101663250B1 KR 101663250 B1 KR101663250 B1 KR 101663250B1 KR 1020150095701 A KR1020150095701 A KR 1020150095701A KR 20150095701 A KR20150095701 A KR 20150095701A KR 101663250 B1 KR101663250 B1 KR 101663250B1
- Authority
- KR
- South Korea
- Prior art keywords
- chat
- message
- decryption key
- chat message
- encryption
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L51/00—User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
- H04L51/04—Real-time or near real-time messaging, e.g. instant messaging [IM]
- H04L51/046—Interoperability with other network applications or services
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0838—Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Computer Security & Cryptography (AREA)
- Information Transfer Between Computers (AREA)
Abstract
When providing a secret chat using rejection encryption, receiving a chat message in a chat window in which two or more users participate, applying a probabilistic language model to sentences in a predetermined data set, Encrypts the resultant data of the rejection encoding by using the encryption key, and transmits the encrypted chat message to the chat device of another user participating in the chat window. The encrypted chat message is transmitted to the chat device Decryption is performed corresponding to rejection decoding and encryption based on a probabilistic language model. When decrypting is performed using a real decryption key corresponding to an encryption key, the message is decrypted with the same chat message as the original chat message, and decrypted with a decryption key other than a real decryption key Decrypts the original chat message with a different chat message. It is.
Description
The present invention relates to a chat system and method, and more particularly, to a secret chatting apparatus and method for communicating a secret chatting message by applying a deniable encryption technique.
Generally, when an encrypted message is transmitted and received between a sender and a recipient through an encryption system, an encryption key of a message can be disclosed to a third party inevitably. In this case, it is possible to guarantee the confidentiality of the message by providing a false key to the third party to decrypt the spurious message, not the original message. This technique of decrypting a message with a real key decrypts the real message, but decrypting a message with a pseudo key is called deniable encryption.
In this regard, Ari Juels' 2014 publication entitled "Honey Encryption: Security Beyond the Brute-Force Bound" discloses an encoding and decoding technique that makes it appear as if it were a normal plaintext even if the wrong secret key is entered. However, such conventional rejection encryption techniques are limited to bits or integers. Also, conventional denial-of-encryption techniques are not widely used due to too many computations and inefficient performance. Therefore, there is a need for a denyable encryption system that is efficient and available in the real world.
Meanwhile, in order to ensure confidentiality of a message, a conventional chat system provides a form in which a receiver simply decrypts a message and transmits the message to a recipient in a form of a plain text.
In this connection, Korean Patent Laid-Open No. 10-2001-0016233 (entitled " Encrypted Chatting System ") discloses a method for securely exchanging a key of a chat room with a network in a server side encrypted chatting system, Discloses a method of encrypting an encryption key of a chat room and transmitting the encryption key to a client through a network so that a user participating in the chat receives a key of the encrypted chat room and decrypts the chat room key encrypted with the own private key.
According to this conventional technique, when erroneous secret information is used in the process of decrypting a message, a plaintext that does not make sense as a result value can be output. In this case, the abnormal recipient can recognize that the secret information used by the abnormal recipient is erroneous, and can repeatedly attempt to decrypt the secret information until the real plaintext is obtained using the secret information. In addition, as described above, the encoding and decoding schemes related to the conventional denial-of-encryption techniques do not provide a real-life-applicable implementation method. Therefore, there is a need for a method for providing a new type of secure online communication service to a user by applying a denial encryption technique to a chat system, which is a popular online service.
The embodiment of the present invention applies a rejection encoding and decoding technique to a chat message transmitted by a sender to a recipient in a chat to reject a sentence that is a word even if the recipient decodes the received chat message into erroneous secret information And to provide a secret chatting apparatus and method using encryption.
It should be understood, however, that the technical scope of the present invention is not limited to the above-described technical problems, and other technical problems may exist.
According to an aspect of the present invention, there is provided a secret chatting apparatus using denial-based encryption, the method comprising: applying a probabilistic language model to sentences in a predetermined data set, A sentence information processing unit for storing the generated mapping information; A chat processing unit for generating a chat window in which two or more users participate and displaying the chat message input in the chat window in a chat display area; And processing the input chat message in accordance with the mapping information and transmitting the chat message encrypted with the encryption key to the chat device of another user participating in the chat window And a message transmission unit. At this time, the encrypted chat message is subjected to rejection decoding based on the stochastic language model and decryption corresponding to the encryption in the chat device of the other user, and when decrypting with the real decryption key corresponding to the encryption key, And decrypts the same with a decryption key other than the real decryption key, the message is restored to a chat message different from the inputted chat message.
According to another aspect of the present invention, there is provided a secret chatting method using denial-based encryption through a secret chatting apparatus, comprising: receiving a chatting message input in a chatting window; Rejectively encoding the input chat message based on mapping information generated by applying a probabilistic language model to sentences in a predetermined data set; Encrypting the resultant data of the rejection encoding using an encryption key; And transmitting the encrypted chat message to a chat device of another user participating in the chat window. At this time, the encrypted chat message is subjected to rejection decoding based on the stochastic language model and decryption corresponding to the encryption in the chat device of the other user, and when decrypting with the real decryption key corresponding to the encryption key, And decrypts the same with a decryption key other than the real decryption key, the message is restored to a chat message different from the inputted chat message.
According to another aspect of the present invention, there is provided a secret chatting method using denial-based encryption through a secret chatting device, the method comprising: receiving, from a chatting device of another user participating in an opened chat window, And receiving a chat message encrypted in a predetermined format; Decrypting the received chat message using a decryption key; Performing rejection decoding processing on the resultant data of the decoding based on the probabilistic language model; And displaying a chat message resulting from the rejection decoding in a chat display area of the chat window. In this case, when the decrypted chat message is decrypted with a real decryption key corresponding to the encryption key used in the encryption, the same chat message as the original chat message is restored. When the decrypted chat message is decrypted with a decryption key other than the real decryption key, Message and a different chat message.
According to the present invention, it is possible to prevent a third party from trying to guess and decrypt his / her secret information (i.e., a chat message) at the user side of the secret chatting apparatus. That is, when decrypting the secret chat message using a decryption key other than the real decryption key corresponding to the encryption key, the chat message having a plain or different form from the original chat message is restored. Accordingly, even when the third party is exposed to the third party who is the abnormal recipient and the third party confirms the contents of the chat message, the secret information can be kept confidential by confirming the contents different from the original. Also, by decrypting the chat message restored by the bogus decryption key so as to have a meaningful plain text form, it is difficult to discriminate the false chat message from the original contents, thereby preventing the third party from attempting to decrypt the message.
1 is a block diagram illustrating a configuration of a secret chatting apparatus according to an embodiment of the present invention.
2 is a flowchart illustrating a secret chatting method by encrypting a secret chat message according to an embodiment of the present invention.
3 is a flowchart illustrating a secret chatting method by decrypting a secret chat message according to an embodiment of the present invention.
4A to 4C are views showing an example of a chat window provided through a secret chatting apparatus according to an embodiment of the present invention.
5 is a diagram illustrating an example of a probabilistic language model based sentence information database used in rejection encoding and decoding according to an embodiment of the present invention.
6 is a diagram illustrating another example of a probabilistic language model-based sentence information database according to an embodiment of the present invention.
7 is a diagram illustrating an example of a result of rejection decoding according to an embodiment of the present invention.
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.
Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.
1 is a block diagram illustrating a configuration of a secret chatting apparatus according to an embodiment of the present invention.
The
At this time, the
The
In the following description, the
Meanwhile, at least one configuration of the
1, the
At this time, the
The
In addition, the
Meanwhile, the
As described above, in the embodiment of the present invention, the user (i.e., the sender and the receiver) directly inputs the encryption key or the decryption key through the interface provided by the
The sentence
As shown in FIG. 1, the sentence
The sentence
Then, the sentence
The
The
1, the
The
The rejecting
The
The encryption
In addition, the encryption
In addition, the encryption
The transmitting
In addition, the
Referring now to FIG. 2, a method of rejecting a chat message through a
2 is a flowchart illustrating a secret chatting method by encrypting a secret chat message according to an embodiment of the present invention.
First, a chat window in which two or more users participate is opened (S210), and a chat message (i.e., a source chat message) input in the corresponding chat window is received (S220).
Then, the original chat message is rejectively encoded based on the mapping information generated by applying the probabilistic language model to the sentences in the predetermined data set (S230).
At this time, the original chat message is in the form of plain text, and it can process the rejection encoding to convert the original chat message into binary data according to predetermined mapping information.
For reference, before the step S230, a predetermined feature extraction algorithm is applied to extract a feature element in a sentence-by-sentence structure in a data set, a probabilistic language for assigning a probability in a data set to a feature element Calculating a cumulative distribution for each feature element based on the model, and generating mapping information by mapping the corresponding binary code information for each cumulative distribution. The generated mapping information is stored and used for rejecting a later chat message or for rejecting a received chat message.
Then, the resultant data of the rejected encoding is encrypted using the encryption key (S240).
[0034] After the step S240, an interface for receiving an encryption key to be used for encryption of the original chat message may be provided, and then the encryption key input by the user through the interface may be used as the encryption key.
Then, the encrypted chat message is transmitted to the chat device of another user participating in the chat window (S250).
Referring back to FIG. 1, the
1, the
The receiving
The
The decryption
In addition, the decryption
The
Hereinafter, a method for rejecting and decrypting a secret chat message through the
3 is a flowchart illustrating a secret chatting method by decrypting a secret chat message according to an embodiment of the present invention.
First, a chat window in which two or more users are participating is opened (S310), and a rejection encoding based on a predetermined probabilistic language model and a chat message encrypted in a predetermined format That is, a secret chat message) (S320).
Then, the received secret chat message is decrypted using the set decryption key (S330).
At this time, the decrypted secret chat message is decoded into binary data. In addition, before decrypting the received secret chat message, an interface for receiving a decryption key to be used for decryption may be provided, and decryption may be performed using the decryption key input through the interface.
Thereafter, the resultant data of the decoding is subjected to rejection decoding based on the probabilistic language model (S340).
At this time, the decoded binary data is converted into a plain text chat message according to the mapping information. If the chat message decrypted with the real decryption key is decrypted, the same chat message as the original chat message is decrypted. If the decrypted chat message decrypted with a decryption key other than the real decryption key is rejected, A chat message different from the chat message is decoded.
In addition, before the rejection decoding process is performed in step S340, a predetermined feature extraction algorithm is applied to the sentences in the predefined data set to extract the feature elements according to sentences, Calculating a cumulative distribution for each feature element based on a probabilistic language model that is the same as the probabilistic language model used for encrypting the secret chat message, and generating mapping information by mapping the corresponding binary code information for each cumulative distribution .
Then, a chat message resulting from the rejection decoding is displayed in the chat display area of the chat window (S350).
Hereinafter, an example of the secret chatting method using the rejection encryption described above will be described in detail with reference to FIG.
4 is a diagram illustrating an example of a chat window provided through a secret chatting apparatus according to an embodiment of the present invention.
4A, 4B, and 4C show chat windows implemented through the
4A, 4B and 4C, the sender and the receiver respectively input 'destination information' such as an IP address and a port number of a communication counterpart, and input 'ID' as its identification information and 'Password' Can be input. The input 'Password' is a secret key used in the encryption algorithm, and is an encryption key or a decryption key used for encrypting or decrypting a chat message. The
4A, when the sender alice inputs a message to be transmitted through the input window at the lower part of the chat display area, the
4B, the
4C, the
Hereinafter, a method for generating mapping information based on a probabilistic language model to be used for rejection encoding and decoding according to an embodiment of the present invention and a method for storing the generated mapping information in a sentence information database will be described with reference to FIGS. 5 to 7 Will be described in detail.
The
Specifically, in the rejection encoding, the real plaintext (i.e., the original chat message) is converted into binary data. At this time, a probabilistic language model is applied instead of the conventional method such as the ASCII code table as the conversion standard. A probabilistic language model is a probability model that assigns probabilities to a series of strings, for example, the probability that a particular letter (e.g., " e ") will appear in an English word or sentence, the probability that a particular letter will appear in the first letter of the word, The probability that a particular word (e.g., " the ") will appear in an English sentence, or the probability that a second specific word (e.g., " love & It is. In rejection decoding, binary data (i.e., secret chat messages) are converted into chat messages using the same probabilistic language model as that used in the rejection encoding. In the above-described probability model, examples of conditions for assigning probabilities to each character included in a series of strings can all be used as feature elements in the construction of the sentence. For example, an example of a condition for assigning a probability to a string of strings is a condition in which a specific letter in a string such as a word or a sentence appears, a condition in which a specific letter in a string comes out successively, a condition in which a specific letter appears as a first letter of the word, A condition in which a specific word is to be generated, a condition in which another specific character appears in succession to a specific word in the sentence, and the like.
5 is a diagram illustrating an example of a probabilistic language model based sentence information database used in rejection encoding and decoding according to an embodiment of the present invention.
Here, FIG. 5 shows a statistical language model for the first letter in the sentence.
Specifically, FIG. 5 shows the probability p (X1) of the first letter of each letter (i.e., 'a, b, ..., z') in English sentences and the letter p , b, ..., z ') and the cumulative distribution of the probabilities for each character are encoded, a 2L x 1 size lattice space in which each element is represented by an L-bit binary code is stored Respectively. That is, each element of the lattice space represents a binary code corresponding to the cumulative distribution of each character.
The sentence used in the statistical language model is not limited to the English sentence, and the letter to judge the first letter condition is also not limited to the English alphabet. That is, the character condition may be a special character such as a number or a punctuation mark as well as the English alphabet (a, b, ..., z). Also, the lattice space is not an actual physical space, and each character of the plain text is mapped to one of the values stored in the lattice space and is rejectively encoded.
In the rejection encryption method according to an embodiment of the present invention, the probabilistic language model can be utilized as follows.
First, the position of t as the first letter in the cumulative distribution shown in FIG. 5 is found. Then, a binary code set having an L bit length corresponding to the cumulative distribution position of t in the lattice space of Fig. 5 is found. As shown, if there are a plurality of candidates corresponding to the cumulative distribution of the letters t in the lattice space, the first candidate can be selected.
For example, when trying to encrypt the plaintext "the school", the probability cumulative distribution of the condition that t is the first letter of the sentence in FIG. 5 is in the range of 72.749% to 89.420%. At this time, the elements corresponding to the positions of the 72.749% to 89.420% intervals in the lattice space of FIG. 5 are shaded sections. As such, since there are a plurality of corresponding candidates, the first candidate can be selected. That is, the binary data value of the first candidate is 10 ... Assuming 11, the letter t is 10 ... 11.
Through this process, the rejected encoding can be performed by applying binary data mapped according to preset conditions (i.e., constituent feature elements) for each character of the plain text "the school ". Referring to FIG. 6, a rejection encoding applied to other characters of a plain text will be described using mapping information generated based on another probabilistic language model.
6 is a diagram illustrating another example of a probabilistic language model-based sentence information database according to an embodiment of the present invention.
Here, FIG. 6 shows a statistical language model applied to arbitrary first letters in a series of strings. For reference, FIG. 6 shows the application of a probability model in which conditional probability is taken into account, and encoding of other characters (other orders) in the string can similarly be performed.
For example, the encoding for the third letter "e" in the string "the school" is the probability that the third letter is "e" when the first letter is "t" and the second letter is "h" (X3 = e | X2 = h, X1 = t)).
As shown in FIG. 6, there are a plurality of encoding candidates which are intervals corresponding to the cumulative distribution of the probability, and a binary data value, which is the first candidate among a plurality of candidates, is set as an encoding value of the corresponding character .
Meanwhile, the rejection decoding process according to an embodiment of the present invention can be performed by reversing the encoding process described above.
Specifically, when a specific string is encrypted with a rejection encoding and encryption key based on the probabilistic language model described above, the encrypted string is decrypted with the decryption key upon restoration of the corresponding string, Based on the language model. For the sake of convenience, the binary data values are represented by hexadecimal numbers in the following description.
For example, assume that the word "crypto" is rejected encoded based on the probabilistic language model described above as '35 21 2B 62 44 A2'. In addition, it is assumed that a result obtained by encrypting the result of the rejection encoding with the encryption key is '73 C3 39 13 F2 37 '.
At this time, when the encrypted character string '73 C3 39 13 F2 37 'is decrypted using the real decryption key corresponding to the encryption key,' 35 21 2B 62 44 A2 'which is a result value of the original rejection encoding can be obtained have. Then, the binary data values stored in the lattice space of the corresponding probability model (for example, the probability models described in FIGS. 5 and 6) for each value of '35 21 2B 62 44 A2' Check the distribution value. Then, the rejection decoding can be processed by extracting the character having the ascertained cumulative distribution value. As a result, the original string "crypto" can be restored. For reference, the probability model corresponding to each value among '35 21 2B 62 44 A2' corresponds to the probability model applied to the rejection encryption, and it is also possible to use a probability model having the same one or more values.
On the other hand, in the case of restoring the encrypted string '73 C3 39 13 F2 37 ', when decrypting with the decryption key other than the decryption key corresponding to the encryption key, a value other than the original binary data value (for example, '78 3F 22 56 1F 30 '). In this case, the cumulative distribution value mapped to the corresponding one of the binary data values stored in the lattice space of the corresponding probability model for each of the result values of decoding '78 3 F 22 56 1F 30' is confirmed. Then, a character having an ascertained cumulative distribution value is extracted to process rejection decoding. At this time, since the values decoded by the fake decryption key are different from the original binary data value, the restored character string as a result of the rejection decoding is also restored to a character string different from the original character string (e.g., " crypto " do. At this time, the values decoded with the fake decryption key can also be subjected to the rejection decoding using the probability model corresponding to the probability model previously applied to the rejection encoding.
The
As described above, if a rejection encryption method according to an embodiment of the present invention is applied, a plaintext can be generated which is meaningful or meaningful even for a false chat message. That is, in the conventional encryption technique, when a given cipher text is decrypted using a pseudo key, a binary code having no meaning is generated. For example, if you use ASCII code, decrypting the ciphertext encrypted with "the school" with a bogus decryption key will result in a fake chat message with a meaningless string, such as "@ 8hk * s". However, according to one embodiment of the present invention, a false chat message may also be restored to a meaningful string (i.e., plain text form) such as "an apple. &Quot;
The cumulative distribution of characters in the data set based on the above probabilistic language model and the corresponding binary code information (i.e., mapping information) are stored in the
5 and 6, in the embodiment of the present invention, the cumulative distribution of each constituent feature element in the sentence (or character string) in the predetermined data set is a training process for the data set Can be obtained through. That is, in the
This means that a specialized database can be used with various data sets. For example, if a user builds a language model through the Bible as a set of data, the database will have a cumulative distribution of the Bible. On the other hand, when language models are constructed through economic news as a data set, they will have a cumulative distribution that differs significantly from the cumulative distribution of language models built through the Bible. For example, in the Bible the frequency of the word "love" is high, but in economic news, the frequency of words that would not appear in the "account" scripture would be high. Utilizing this characteristic, the
7 is a diagram illustrating an example of a result of rejection decoding according to an embodiment of the present invention.
In FIG. 7, the first column shows the types of data sets (data) used to generate the mapping information based on the probabilistic language model. For example, NASA documents, novels 'Romeo and Juliet', cryptography documents, bibles, and classical music documents were used as data sets.
The second column of FIG. 7 shows a result of decrypting a rejected encoding and a character string encrypted with the encryption key by using a real decryption key to reject the decrypted character. That is, a real plaintext is restored when a real decryption key K1 is used to decrypt a ciphertext (i.e., a secret chat message).
The third column and the fourth column in FIG. 7 show the plaintexts reconstructed by rejecting decryption and decryption when a cryptographically deciphered decryption key (K2 or K3) arbitrarily selected. As shown in the third and fourth columns of FIG. 7, a false plaintext is generated for each set of data applied to the modeling of the probability model, which is completely different from the true plaintext, but looks meaningful. At this time, each plaintext restored with the fake decryption key can be understood that the meaning and the form are related to the characteristics of the data according to the data (ie, data set) used in the training (learning) of the probability model. For example, when using cryptographic documents as training data for probabilistic models, the phrases or clauses that appear in cryptography documents (ie, "the secret key signatu" and "the probabilistic tech") have been restored. Also, when classical music documents were used as training data for probability models, phrases or phrases that appeared in music documents (ie, "sym orchphil. Classic" and "beethovenl.v.
The
The secret chatting method using rejection encryption according to an embodiment of the present invention described above can also be implemented in the form of a recording medium including instructions executable by a computer such as a program module executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. The computer readable medium may also include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.
It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.
The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.
10: Secret Chat Device
100:
200: sentence information processing section
300:
400:
Claims (15)
A sentence information processing unit for storing mapping information generated by applying a probabilistic language model to sentences in a predetermined data set;
A chat processing unit for generating a chat window in which two or more users participate and displaying the chat message input in the chat window in a chat display area; And
A message for processing a rejected encoding of the input chat message based on the mapping information and transmitting a chat message in which the resultant data of the rejection encoding is encrypted with an encryption key to a chat device of another user participating in the chat window And a transmitter,
Wherein the chat processing unit provides a first input interface by generating an interface window for receiving an encryption key to be used for encrypting the input chat message separately from the chat window,
Wherein the message transmission unit processes the encryption using an encryption key input through the first input interface,
The encrypted chat message may include:
And decrypting the decrypted content using the decryption key corresponding to the encryption key when the decryption key is decrypted based on the stochastic language model and the decryption corresponding to the encryption in the chat device of the other user, If the decryption key is decrypted using a decryption key other than the real decryption key, the decryption key is restored to a chat message different from the inputted chat message,
The second user's chat device is provided with a second input interface for inputting a decryption key to be used for decrypting the received chat message,
Wherein the real decryption key is automatically input in the decryption process when the real decryption key predetermined in advance is stored in the chat device of another user.
The sentence information processing unit,
Extracting a characteristic feature element in a sentence-by-sentence structure from the data set by applying a predetermined sentence feature extraction algorithm,
Calculating cumulative distribution for each feature element based on the probabilistic language model that assigns a probability in the data set to the feature element,
And mapping the corresponding binary code information for each cumulative distribution to generate the mapping information.
Wherein the message transmitter comprises:
And converting the input chat message in a plain text form into binary data according to the mapping information in the rejection encoding.
Receiving the rejected encoding and the encrypted chat message from another user's chat device, decrypting the received chat message using a decryption key, decrypting the decrypted result data based on the mapping information, And a message receiving unit for processing the received message,
The chat processing unit,
And displaying the rejected decoded chat message in the chat display area of the corresponding chat window.
Wherein the message receiver comprises:
Decodes the received chat message into binary data through decoding corresponding to the encryption and converts the binary data into a plain text chat message based on the mapping information upon rejection decoding Secret chatting device using deny encryption.
When a decryption key other than the real decryption key is used as the decryption key, the received chat message is converted into a plain text form through the rejection decoding and converted into a false chat message having a different meaning and form from the input chat message Secret chatting device using denial encryption.
The chat processing unit,
And a third input interface for receiving a decryption key for decrypting the received chat message,
And the message receiver processes the decryption using the decryption key input through the third input interface.
Receiving an input chat message in the opened chat window;
Rejectively encoding the input chat message based on mapping information generated by applying a probabilistic language model to sentences in a predetermined data set;
Providing a first input interface for receiving an encryption key to be used for encrypting the input chat message;
Encrypting the resultant data of the rejection encoding using an encryption key input through the first input interface; And
And transmitting the encrypted chat message to a chat device of another user participating in the chat window,
The encrypted chat message may include:
And decrypting the decrypted content using the decryption key corresponding to the encryption key when the decryption key is decrypted based on the stochastic language model and the decryption corresponding to the encryption in the chat device of the other user, If the decryption key is decrypted with a decryption key other than the real decryption key, the decryption key is restored to a chat message different from the inputted chat message,
The second user's chat device is provided with a second input interface for inputting a decryption key to be used for decrypting the received chat message,
Wherein the real decryption key is automatically input in the decryption process when the real decryption key predetermined in advance by the another user's chat device is stored.
Before the step of rejectively encoding the input chat message,
Extracting a feature element on the basis of sentences in the data set by applying a predetermined sentence feature extraction algorithm;
Calculating a cumulative distribution for each feature element based on the probabilistic language model that assigns probabilities in the data set to the feature elements; And
And generating the mapping information by mapping the corresponding binary code information for each cumulative distribution.
The rejecting encoding process of the input chat message may include:
A secret chatting method using rejection encryption for converting the input chat message in a plain text form into binary data according to the mapping information.
Receiving a chat message encrypted based on a predetermined probabilistic language model and a predetermined format from a chat device of another user participating in the opened chat window;
Providing an input interface for receiving a decryption key for decrypting the received chat message;
Decrypting the received chat message using a decryption key input through the input interface;
Performing rejection decoding processing on the resultant data of the decoding based on the probabilistic language model; And
And displaying a chat message resulting from the rejection decoding in a chat display area of the chat window,
The received chat message may include:
When decrypting the decrypted content using a decryption key corresponding to an encryption key used in encryption, decrypting the decrypted content using a decryption key other than the decrypted key is restored to a chat message different from the original decryption key,
Wherein when the real decryption key promised in advance is stored, the decrypting step automatically decrypts the pre-stored real decryption key by using the decrypted real decryption key.
Before the rejecting decoding processing step,
Extracting a feature element in a sentence-by-sentence structure by applying a predetermined sentence feature extraction algorithm to sentences in a predetermined data set;
Calculating a cumulative distribution for each feature element based on the probabilistic language model that assigns probabilities in the data set to the feature elements; And
And mapping the corresponding binary code information for each cumulative distribution to generate mapping information.
Wherein the rejecting decoding processing includes:
And converting the binary data obtained as a result of the decoding of the received chat message into a plain text chat message according to the mapping information.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20150071737 | 2015-05-22 | ||
| KR1020150071737 | 2015-05-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR101663250B1 true KR101663250B1 (en) | 2016-10-14 |
Family
ID=57156976
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020150095701A KR101663250B1 (en) | 2015-05-22 | 2015-07-06 | Secret chatting apparatus and method using deniable encryption |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR101663250B1 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150010571A (en) * | 2013-07-19 | 2015-01-28 | 고려대학교 산학협력단 | System and method for deniable encryption |
| KR101489447B1 (en) * | 2013-06-17 | 2015-02-03 | 김도형 | System for encoding information by encrypting message into common conversation |
-
2015
- 2015-07-06 KR KR1020150095701A patent/KR101663250B1/en active IP Right Grant
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101489447B1 (en) * | 2013-06-17 | 2015-02-03 | 김도형 | System for encoding information by encrypting message into common conversation |
| KR20150010571A (en) * | 2013-07-19 | 2015-01-28 | 고려대학교 산학협력단 | System and method for deniable encryption |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9485096B2 (en) | Encryption / decryption of data with non-persistent, non-shared passkey | |
| US8989385B2 (en) | Data encryption method, data verification method and electronic apparatus | |
| US20110145576A1 (en) | Secure method of data transmission and encryption and decryption system allowing such transmission | |
| CN106506487A (en) | A kind of information Encrypt and Decrypt method and device | |
| WO2014132552A1 (en) | Order-preserving encryption system, device, method, and program | |
| Pandya et al. | Brief history of encryption | |
| CN104243149A (en) | Encrypting and decrypting method, device and server | |
| JP2016522931A (en) | Blocking password attacks | |
| CN109923516A (en) | Reinforce computer security, variable word length coding and the decoded technology of variable length code | |
| Abiodun et al. | Reinforcing the security of instant messaging systems using an enhanced honey encryption scheme: the case of WhatsApp | |
| Rahman et al. | Development of cryptography-based secure messaging system | |
| CN114567427B (en) | Block chain hidden data segmented transmission method | |
| KR101584127B1 (en) | System and method for deniable encryption | |
| CN104486756A (en) | Encryption and decryption method and system for secret letter short message | |
| CN112637230B (en) | Instant messaging method and system | |
| CN112398646B (en) | Identity-based encryption method and system with short public parameters on ideal lattice | |
| Manasrah et al. | Mapping private keys into one public key using binary matrices and masonic cipher: Caesar cipher as a case study | |
| WO2012152956A1 (en) | Shannon security double symmetrical cryptogram method by coding information for telematic and electronic transmission | |
| Patni | A poly-alphabetic approach to Caesar cipher algorithm | |
| JP2001282103A (en) | Ciphering method | |
| KR101663250B1 (en) | Secret chatting apparatus and method using deniable encryption | |
| KR100577875B1 (en) | Encryption/decryption method of transmission data | |
| Flaut et al. | From old ciphers to modern communications | |
| Disina et al. | Enhanced caeser cipher to exclude repetition and withstand frequency cryptanalysis | |
| CN102238150A (en) | Form registration method and server |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant | ||
| FPAY | Annual fee payment |
Payment date: 20190808 Year of fee payment: 4 |