An encryption method and system based on LCT chaotic mapping and blockchain

Abstract

The present invention discloses an encryption method and system based on LCT chaotic mapping and blockchain, which relates to the technical field of cryptography, and is characterized in that it comprises the following steps: S1: an encryption algorithm based on LCT chaotic mapping - LCTCME. The present invention innovatively proposes a newly constructed one-dimensional chaotic system to construct a secure information encryption system based on blockchain. In the newly proposed one-dimensional logic-cosine-tangent chaotic system, the cosine function and tangent function that constitute it replace the two variables in the logical mapping respectively, thereby improving the dynamics of the new one-dimensional chaotic mapping. The information encryption scheme constructed based on the one-dimensional chaotic system relies on the authority management function of the blockchain smart contract to design a key transmission scheme, while achieving the security of the encryption algorithm and the reliability of the key transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of cryptography, and in particular to an encryption method and system based on LCT chaotic mapping and blockchain. Background Art

[0002] With the improvement of information security requirements, information encryption, as a common information protection method, has been widely studied by scholars in recent years. Chaos-based information encryption methods have become one of the most commonly used design techniques for designing new encryption algorithms. With the increase of information data to be encrypted, the security of chaotic information encryption has become particularly important. As a result, how to prevent attackers from obtaining valid information from ciphertext information or destroying the normal decryption effect has become a problem worth studying.

[0003] As the core of chaotic encryption algorithms, chaotic systems have achieved many important research results in recent years, which are mainly reflected in the innovation of one-dimensional chaotic systems, two-dimensional chaotic systems, high-dimensional chaotic systems, and space-time chaotic systems. One-dimensional chaotic systems seem to have weak chaotic properties due to their simple algebraic structure, but they play an important role as the basis for multidimensional chaos research and space-time chaos research.

[0004] The combination of classical chaotic systems and trigonometric functions has innovated the research on one-dimensional chaotic systems.

[0005] (1) The Logistic mapping is combined with the Tent mapping to propose the Logistic-Tent mapping, which combines the good chaotic characteristics of the Logistic mapping and the duality of the Tent mapping, making the Logistic-Tent mapping have better chaotic characteristics;

[0006] (2) A new one-dimensional cos-cot system with better chaotic performance than the traditional chaotic system. The system nests the cosine function and the cotangent function to obtain a new one-dimensional cos-cot system with better chaotic performance than the traditional chaotic system.

[0007] (3) By coupling the sine graph and the logistic graph, a new one-dimensional chaotic system is constructed, in which two sine operations are performed, which effectively improves the one-dimensional chaotic graph;

[0008] (4) By introducing the hyperbolic tangent function and the time lag factor to construct a one-dimensional chaotic system, the choice of one-dimensional chaotic mapping decomposition function is expanded to improve the nonlinear dynamic performance;

[0009] (5) Divide the two factorized functions of cosine and sine.

[0010] This new type of chaotic system is constructed in the form of cosine function being superior to sine function, so that the designed encryption algorithm has better security accordingly.

[0011] At present, there is still a lack of a new one-dimensional chaotic system. The cosine function and tangent function are used to replace the variable terms in the classical Logistic mapping. The information cryptographic system designed by using the good chaotic characteristics of the new one-dimensional chaotic system and the key sending scheme of the blockchain smart contract effectively improves the security of the cryptographic algorithm and the reliability of key transmission. At the same time, it emphasizes the importance of using blockchain-based key management methods to enhance encryption technology. Summary of the invention

[0012] The technical problem to be solved by the present invention is to provide an encryption method and system based on LCT chaotic mapping and blockchain, innovatively propose a newly constructed one-dimensional chaotic system, and build a secure information encryption system based on blockchain. In the newly proposed one-dimensional logic-cosine-tangent (LCT) chaotic system, the cosine function and tangent function that constitute it replace the two variables in the logical mapping, respectively, thereby improving the dynamics of the new one-dimensional chaotic mapping. The information encryption scheme constructed based on the one-dimensional chaotic system relies on the authority management function of the blockchain smart contract to design the key transmission scheme, while achieving the security of the encryption algorithm and the reliability of key transmission.

[0013] The present invention adopts the following technical solutions to achieve the invention objectives:

[0014] An encryption method based on LCT chaotic mapping and blockchain, characterized in that it comprises the following steps:

[0015] S1: Encryption algorithm based on LCT chaotic mapping - LCTCME;

[0016] S11: Use column-first traversal method to input plain text information data , calculate the width M and height N;

[0017] S12: Calculation using hash function The hash value generates a 128-length hexadecimal string , then for the string The hexadecimal numbers in are XORed in pairs and converted to decimal to obtain a decimal vector with a length of 64. , and then perform algebraic operations to Convert to key ;

[0018] in: ;

[0019] ;

[0020] ;

[0021] S13: Through the newly proposed, with two key groups and The LCT chaos map is obtained The length of the chaotic sequence and ;in and is the initial stage of the chaotic system. and Considered to be The value of the system, at the same time, and is the length of the deleted sequence, thus ensuring and state of confusion;

[0022] S14: Get an index vector From The positions of the scrambled backup elements in the original vector are based on Re-shuffle , the re-scrambled information is expressed as ;

[0023] S15: Use the second chaos sequence right Change the information position and get the information of the changed position :

[0024] S16: Column-first traversal Method to output the encrypted ciphertext information ;

[0025] According to the above six steps, the ciphertext information is obtained, and the key sequence is composed of , used to encrypt and decrypt information;

[0026] S2: Decryption algorithm based on LCT chaotic mapping - LCTCMD.

[0027] As a further limitation of the technical solution, the LCT chaotic mapping introduces cosine function and tangent function on the basis of logical mapping, so that the complexity of the mapping in the iterative process is significantly changed, thereby enhancing the chaotic properties of the new mapping and showing better chaotic characteristics.

[0028] As a further limitation of the technical solution, the specific steps of S2 are:

[0029] S21: Use column-first traversal method to input the information data to be decrypted , calculate the width as M and the height as N;

[0030] S22: Enter the key group ;

[0031] S23: Obtain the newly proposed LCT chaotic map with key The length of the chaotic sequence and ;

[0032] S24: With the Second Chaos Sequence To change The information data value of the reverse diffusion is obtained ;

[0033] S25: Get an index vector From The position of the sorted backup elements in the original vector, Pixels by Perform inverse scrambling and express the inverse scrambled information as ;

[0034] S26; Column-first traversal Method to output the decrypted information ;

[0035] After the above six steps, the decrypted information is obtained using the same key sequence as the encryption process. The key sequence is composition.

[0036] A processing system for an encryption method based on LCT chaos mapping and blockchain, comprising the following steps:

[0037] S31: Alice uses LCTCME to obtain the encrypted information and key, and then calculates the hash value of the encrypted information;

[0038] S32: Alice uploads the encryption key, the hash value of the encrypted information, and the user ID that has the right to decrypt;

[0039] S33: The smart node of the blockchain writes the ciphertext hash, transaction time, encryption user, decryption user and block header into the new block;

[0040] S34: Alice transmits the encrypted information to Bob, and Alice hopes that Bob can use the correct key to obtain the correct plaintext information;

[0041] S35: Bob receives the encrypted information and then uploads his ID to the smart node for identity authentication;

[0042] S36: The smart node of the blockchain sends the key to Bob;

[0043] S37: Bob uses LCTCMD and the key from the smart node to decrypt the ciphertext information and obtain the plaintext information;

[0044] Through the above steps, secure transmission of encrypted information based on blockchain can be achieved.

[0045] As a further limitation of the present technical solution, in the key transmission scheme based on blockchain intelligent nodes, the ID of each user in the blockchain is unique and cannot be copied.

[0046] Compared with the prior art, the advantages and positive effects of the present invention are:

[0047] 1. The present invention designs a chaotic mapping system named after the logical-cosine-tangent mapping. By introducing the cosine function and the tangent function, the complexity of the mapping is significantly changed during the iteration process, thereby enhancing the chaotic properties of the new mapping and showing better chaotic characteristics.

[0048] 2. The present invention designs a chaotic information encryption and decryption algorithm based on LCT. By using the chaotic characteristics of the LCT-based chaotic mapping system and applying it to the numerical change process of information data, the value of the original information data can be greatly changed by using the LCT-based chaotic mapping system as the operation relationship of the numerical change of information data, thereby improving the effect of the diffusion process.

[0049] 3. The present invention designs a ciphertext information encryption system based on blockchain. The security of blockchain smart contracts can be used for information encryption authority management. The encryption key of the information is stored in the smart contract. Only users with decryption authority can decrypt the information. This can protect information privacy to the greatest extent, maintain the secure transmission between the sender and receiver of the ciphertext message, and prevent key leakage from threatening the transmission security of ciphertext information. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a system flow chart of the present invention.

[0051] Figure 2 This is an example of the encryption and decryption process in the LCT algorithm encryption system of the present invention. DETAILED DESCRIPTION

[0052] A specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation.

[0053] The present invention comprises the following steps:

[0054] S1: Encryption algorithm based on LCT chaotic mapping - LCTCME;

[0055] S11: Use column-first traversal method to input plain text information data , calculate the width M and height N;

[0056] S12: Calculation using hash function The hash value generates a 128-length hexadecimal string , then for the string The hexadecimal numbers in are XORed in pairs and converted to decimal to obtain a decimal vector with a length of 64. , and then perform algebraic operations to Convert to key ;

[0057] in: ;

[0058] ;

[0059] ;

[0060] S13: Through the newly proposed, with two key groups and The LCT chaos map is obtained The length of the chaotic sequence and ;in and is the initial stage of the chaotic system. and Considered to be The value of the system, at the same time, and is the length of the deleted sequence, thus ensuring and state of confusion;

[0061] S14: Get an index vector From The positions of the scrambled backup elements in the original vector are based on Re-shuffle , the re-scrambled information is expressed as ;

[0062] S15: Use the second chaos sequence right Change the information position and get the information of the changed position :

[0063] S16: Column-first traversal Method to output the encrypted ciphertext information ;

[0064] According to the above six steps, the ciphertext information is obtained, and the key sequence is composed of , used to encrypt and decrypt information;

[0065] S2: Decryption algorithm based on LCT chaotic mapping - LCTCMD.

[0066] The LCT chaotic mapping is a chaotic mapping system named after the logical-cosine-tangent (LCT) mapping, which introduces cosine function and tangent function on the basis of logical mapping. The complexity of the mapping is significantly changed during the iteration process, and the chaotic properties of the new mapping are enhanced to show better chaotic characteristics.

[0067] The logistic map is a second-degree polynomial map that is often cited as a prototypical example of how very simple nonlinear dynamical equations can give rise to complex, chaotic behavior.

[0068] The newly proposed LCT exhibits good Lyapunov exponent performance, bifurcation phenomenon effect and pseudo-randomness.

[0069] The Lyapunov exponent can intuitively show whether a system is in a chaotic state. When the system is in a chaotic state, the Lyapunov exponent should be greater than 0.

[0070] Bifurcation phenomenon is the qualitative change of the qualitative behavior of a dynamic system as the parameters related to the system change change.

[0071] The specific steps of S2 are:

[0072] Since the proposed encryption algorithm is symmetric and reversible, the decryption process is the inverse process of the encryption process. Based on the above-mentioned decryption algorithm based on LCT chaotic mapping, when the key is known, LCT chaotic mapping information decryption (LCTCMD) can be achieved through the following steps.

[0073] S21: Use column-first traversal method to input the information data to be decrypted , calculate the width as M and the height as N;

[0074] S22: Enter the key group ;

[0075] S23: Obtain the newly proposed LCT chaotic map with key The length of the chaotic sequence and ;

[0076] S24: With the Second Chaos Sequence To change The information data value of the reverse diffusion is obtained ;

[0077] S25: Get an index vector From The position of the sorted backup elements in the original vector, Pixels by Perform inverse scrambling and express the inverse scrambled information as ;

[0078] S26; Column-first traversal Method to output the decrypted information ;

[0079] After the above six steps, the decrypted information is obtained using the same key sequence as the encryption process. The key sequence is composition.

[0080] By comparing the information encryption process and decryption process based on LCT chaotic mapping, it can be found that the cryptographic system designed in this paper is symmetric.

[0081] A processing system for an encryption method based on LCT chaotic mapping comprises the following steps:

[0082] When users transmit information, they obtain encrypted information and keys, which are written into new blocks through the nodes of the blockchain. Users who wish to obtain information will obtain the key to decrypt it. The specific steps are as follows:

[0083] S31: Alice uses LCTCME to obtain the encrypted information and key, and then calculates the hash value of the encrypted information;

[0084] S32: Alice uploads the encryption key, the hash value of the encrypted information, and the user ID that has the right to decrypt;

[0085] S33: The smart node of the blockchain writes the ciphertext hash, transaction time, encryption user, decryption user and block header into the new block;

[0086] S34: Alice transmits the encrypted information to Bob, and Alice hopes that Bob can use the correct key to obtain the correct plaintext information;

[0087] S35: Bob receives the encrypted information and then uploads his ID to the smart node for identity authentication;

[0088] S36: The smart node of the blockchain sends the key to Bob;

[0089] S37: Bob uses LCTCMD and the key from the smart node to decrypt the ciphertext information and obtain the plaintext information;

[0090] Through the above steps, secure transmission of encrypted information based on blockchain can be achieved.

[0091] Through such a blockchain workflow design, the leakage of key transmission during the transmission of ciphertext information is eliminated, the security of the key is guaranteed, and the secure transmission between the sender and receiver of the ciphertext message is maintained.

[0092] In the key transmission scheme based on blockchain smart nodes, it is necessary to assume that the ID of each user in the blockchain is unique and cannot be copied.

[0093] The above disclosure is only a specific embodiment of the present invention, but the present invention is not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. An encryption method based on LCT chaotic mapping and blockchain, characterized in that: The following steps are involved: S1: The encryption algorithm based on LCT chaotic mapping - LCTCME encrypts the plaintext information data, specifically: S11: Use column-first traversal method to input plain text information data , calculate the width M and height N; S12: Calculation using hash function The hash value generates a 128-length hexadecimal string , then for the string The hexadecimal numbers in are XORed in pairs and converted to decimal to obtain a decimal vector with a length of 64. , and then perform algebraic operations Convert to key ; in: ; ； ； S13: Through the newly proposed, with two key groups and The LCT chaos map is obtained The length of the chaotic sequence and ;in and is the initial stage of the chaotic system. and Considered to be The value of the system, at the same time, and is the length of the deleted sequence, thus ensuring and state of confusion; S14: Get an index vector From The positions of the scrambled backup elements in the original vector are based on Re-shuffle , the re-scrambled information is expressed as ; S15: Use the second chaos sequence right Change the information position and get the information of the changed position : S16: Column-first traversal Method to output the encrypted ciphertext information ; According to the above six steps, the ciphertext information is obtained, and the key sequence is composed of , used to encrypt and decrypt information; S2: The decryption algorithm based on LCT chaotic mapping - LCTCMD decrypts the ciphertext information.

2. The encryption method based on LCT chaotic mapping and blockchain according to claim 1 is characterized in that: The LCT chaotic mapping is based on the logical mapping, and the cosine function and the tangent function are introduced to significantly change the complexity of the mapping in the iterative process, thereby enhancing the chaotic properties of the new mapping and showing better chaotic characteristics.

3. The encryption method based on LCT chaotic mapping and blockchain according to claim 2 is characterized in that: The specific steps of S2 are: S21: Use column-first traversal method to input the information data to be decrypted , calculate the width as M and the height as N; S22: Enter the key group ; S23: Obtain the newly proposed LCT chaotic map with key The length of the chaotic sequence and ; S24: With the Second Chaos Sequence To change The information data value of the reverse diffusion is obtained ; S25: Get an index vector From The position of the sorted backup elements in the original vector, Pixels by Perform inverse scrambling and express the inverse scrambled information as ; S26; Column-first traversal Method to output the decrypted information ; After the above six steps, the decrypted information is obtained using the same key sequence as the encryption process. The key sequence is composition.

4. A processing system using the encryption method based on LCT chaotic mapping and blockchain as described in claim 3, characterized in that: The following steps are involved: S31: Alice uses LCTCME to obtain the encrypted information and key, and then calculates the hash value of the encrypted information; S32: Alice uploads the encryption key, the hash value of the encrypted information, and the user ID that has the right to decrypt; S33: The smart node of the blockchain writes the ciphertext hash, transaction time, encryption user, decryption user and block header into the new block; S34: Alice transmits the encrypted information to Bob, and Alice hopes that Bob can use the correct key to obtain the correct plaintext information; S35: Bob receives the encrypted information and then uploads his ID to the smart node for identity authentication; S36: The smart node of the blockchain sends the key to Bob; S37: Bob uses LCTCMD and the key from the smart node to decrypt the ciphertext information and obtain the plaintext information; Through the above steps, secure transmission of encrypted information based on blockchain can be achieved.

5. The processing system according to claim 4, characterized in that: In the key transmission scheme based on blockchain smart nodes, the ID of each user in the blockchain is unique and cannot be copied.

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