Image encryption method based on RNA extended coding and quantum chaos

Abstract

The invention discloses an image encryption method based on RNA extended coding and quantum chaos, and belongs to the field of information encryption, and the method comprises the steps: obtaining a plaintext image, coding the plaintext image to obtain initial coding information, and generating a secret key according to the initial coding information; according to the secret key, calculating by adopting a chaos equation to obtain a pseudo-random sequence, and transforming the pseudo-random sequence to obtain a sequence required by encryption; the method comprises the following steps: acquiring a three-dimensional matrix of a plaintext image, decomposing the three-dimensional matrix into a first high-bit matrix and a first low-bit matrix, carrying out block scrambling and RNA dynamic coding on the first high-bit matrix according to a sequence required by encryption, carrying out XOR calculation on the first low-bit matrix according to the sequence required by encryption, and carrying out XOR calculation on the first low-bit matrix according to the sequence required by encryption; carrying out cross iterative diffusion and synthesis on the matrix subjected to RNA dynamic coding and the matrix obtained by XOR calculation to obtain a color ciphertext image; the security and efficiency of information encryption can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of information encryption, and in particular relates to an image encryption method based on RNA extended coding and quantum chaos. Background Art

[0002] While internet technology provides convenient services to users, it has also sparked deep public concern about privacy breaches during data transmission. With the widespread adoption of the internet, the frequency of information transmission over public networks has steadily increased. Digital images, as a simple and intuitive medium that carries a wealth of visual information, are widely used. However, images are vulnerable to corruption and leakage during internet transmission, causing immeasurable losses and harm to users. Therefore, the protection of digital images has become a focus of attention, particularly in areas requiring high confidentiality, such as personal privacy, commerce, and the military. Images contain large amounts of information, strong correlations, and high redundancy. Traditional methods used for text encryption, such as AES, DES, and IDEA, are not suitable for digital image encryption. Against this backdrop, chaos, a deterministic nonlinear system with its stochastic-like behavior, has attracted considerable attention. Chaotic systems are extremely sensitive to initial conditions, exhibiting distinct trajectories under different initial conditions, resulting in unpredictable chaotic signals. These properties give chaos a natural advantage in cryptography, making it a promising new approach for digital image encryption.

[0003] In recent years, the impact of chaotic systems and algorithms on the security of encryption systems has been extensively studied. Prior art has proposed pixel-level and bit-level image encryption algorithms based on two chaotic systems. Experimental simulations and performance analysis demonstrate the high security of these algorithms. Subsequently, a 2D-SECM-based image encryption method was proposed, which includes bit-level scrambling based on a cross-transformation and a round of rapid diffusion. Simulation experiments and security assessments demonstrate that the proposed method is resistant to common attacks. In addition to the aforementioned research, academics have also explored the possibility of combining image encryption with bio-coding techniques. Prior art has proposed an image encryption algorithm based on DNA chain exchange and diffusion. Experimental results and simulation test data demonstrate that this method effectively resists various statistical and noise attacks. Related technologies also utilize dynamic DNA coding, hyperchaotic systems, and elliptic curve cryptography for secure encryption and decryption. Results and analysis demonstrate that these schemes are computationally efficient and highly robust. Another industrial Internet of Things image security model encryption scheme based on chaos and DNA cryptography has been experimentally demonstrated to be resistant to various attacks. Although existing chaotic encryption has made great progress, most of the current methods are unable to resist chosen-plaintext attacks and cannot effectively guarantee information security. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes an image encryption method based on RNA extended coding and quantum chaos to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above objectives, the present invention provides an image encryption method based on RNA extended coding and quantum chaos, comprising:

[0006] Obtaining a plaintext image, encoding the plaintext image to obtain initial encoding information, and generating a key based on the initial encoding information;

[0007] A pseudo-random sequence is calculated using a chaotic equation according to the key, and the pseudo-random sequence is transformed to obtain the sequence required for encryption;

[0008] Obtain a three-dimensional matrix of a plaintext image, decompose the three-dimensional matrix into a first high-bit matrix and a first low-bit matrix, perform block scrambling and RNA dynamic encoding on the first high-bit matrix according to the sequence required for encryption, perform XOR calculation on the first low-bit matrix according to the sequence required for encryption, cross-iteratively diffuse and synthesize the matrix after RNA dynamic encoding and the matrix obtained by XOR calculation to obtain a color ciphertext image.

[0009] Optionally, the pixel values ​​in the plaintext image are calculated using a SHA-256 hash function, and the calculation results of the SHA-256 hash function are converted into decimal numbers every 8 to obtain initial encoding information.

[0010] Optionally, the key generation process includes:

[0011] ;

[0012] Where h represents the initial coding information, and the subscript i represents the initial coding information corresponding to the i-th pixel. Indicates XOR operation, key label , 、 、 、 and Give the key an initial value, 、 、 、 and is the key of the quantum logistic mapping system, where 、 、 represents the system state value of the corresponding quantum logistic mapping system, is an adjustable parameter, represents the dissipation parameter.

[0013] Optionally, the process of generating the sequence required for encryption includes:

[0014] ;

[0015] Among them, S y represents the yth pseudo-random sequence, Indicates the sequence required for the yth encryption, the sequence index y=[1,2,...,8], represents the floor function, Represents the modular arithmetic function.

[0016] Optionally, the process of decomposing the three-dimensional matrix includes:

[0017] Each pixel value in the three-dimensional matrix is ​​represented by an 8-bit binary number, the first 4 binary bits of all pixel values ​​are extracted, the extracted results are bit-level decomposition to generate a first high-bit matrix, and the last 4 binary bits of all pixel values ​​are extracted to generate a first low-bit matrix.

[0018] Optionally, the process of performing block scrambling on the first high-bit matrix includes:

[0019] Performing fixed-size block division on the first high-bit matrix to obtain submatrices, sequentially reorganizing the submatrices into a row to obtain a submatrix sequence, permuting the submatrix sequence according to the first sequence, reorganizing the submatrix according to the permuted sequence to obtain a reorganized first high-bit matrix, rotating the reorganized first high-bit matrix according to a second sequence, wherein information in the second sequence points to different rotation directions and a fixed number of rotations to obtain a second high-bit matrix, and inverting the second high-bit matrix according to a third sequence to obtain a third high-bit matrix, i.e., a block-scrambled matrix;

[0020] The first sequence, the second sequence and the third sequence are respectively the first encryption required sequence, the second encryption required sequence and the third encryption required sequence.

[0021] Optionally, the process of RNA dynamic encoding includes:

[0022] For the block-scrambled matrix, for each element, every three binary digits are combined into an octal number from top to bottom. A coding rule is selected based on the first half of the fifth sequence, and each octal number is encoded according to the selected coding rule to obtain a fourth high-bit matrix. The coding rule includes a correspondence between octal numbers and RNA bases under different rules. Under each rule, each octal number corresponds to only one base, and when the octal numbers are complementary, the bases are also complementary.

[0023] Reorganize the sixth sequence into a two-dimensional matrix with the same length and width dimensions as the plaintext image, and encode the reorganized sixth sequence according to the selected encoding rule to obtain a third sub-matrix;

[0024] selecting an operation mode according to a fourth sequence, wherein the operation mode includes addition, subtraction, and exclusive-or; performing iterative diffusion on the fourth high-bit matrix and the third submatrix according to the selected operation mode to obtain a fifth high-bit matrix;

[0025] In the iterative diffusion, the first-layer matrix of the fourth high-bit matrix and the third submatrix are operated using the selected operation method to obtain the first-layer matrix of the fifth high-bit matrix, and then the k-1-th layer matrix of the fifth high-bit matrix and the k-th layer matrix of the fourth high-bit matrix are operated using the selected operation method to obtain the k-th layer matrix of the fifth high-bit matrix;

[0026] According to the selected coding rule, the pixel value of the last pixel in each row of the fifth high-bit matrix is ​​obtained, and the pixels in the next row are shifted according to the pixel value of the last pixel in each row. For the shifted matrix, the last pixel and the pixel to the right of each row of the fifth high-bit matrix are shifted to the leftmost side of the same row to form a regular matrix, thereby obtaining a sixth high-bit matrix;

[0027] Selecting a coding rule based on the second half of the fifth sequence, decoding the sixth high-bit matrix according to the newly selected coding rule, and synthesizing the decoded sixth high-bit matrix from top to bottom, with every 4 bits forming a pixel value, to obtain the seventh high-bit matrix, which is the matrix after RNA dynamic encoding;

[0028] Among them, the fourth sequence, the fifth sequence and the sixth sequence are respectively the fourth encryption required sequence, the fifth encryption required sequence and the sixth encryption required sequence.

[0029] Optionally, the process of obtaining the color ciphertext image includes:

[0030] Recombining the RNA dynamically encoded matrix and the first low-bit matrix to obtain a high-bit recombined vector and a low-bit recombined vector, and performing an XOR calculation on the low-bit recombined vector using the seventh sequence;

[0031] According to the eighth sequence, the matrix obtained by the XOR calculation and the high-bit reorganized vector are respectively subjected to an addition modulo operation, and pixel values ​​of the addition modulo operation results are synthesized to obtain a color ciphertext image.

[0032] Optionally, after obtaining the color ciphertext image, the following steps are further included:

[0033] The key is transmitted and obtained, the pixel value of the color ciphertext image is segmented, the segmented matrix is ​​reversely iterated and diffused, the sequence required for encryption is obtained according to the key, and the encryption process is reversed according to the required encryption sequence to obtain the plaintext image.

[0034] On the other hand, the present invention also provides an image encryption system based on RNA extended coding and quantum chaos, which is used to execute the above method.

[0035] Compared with the prior art, the present invention has the following advantages and technical effects:

[0036] (1) This invention introduces a new RNA extended encoding mechanism with 384 encoding rules, far exceeding the 8 in traditional methods. It significantly improves the randomness and dynamic characteristics of encryption and effectively enhances the algorithm's ability to resist various attacks.

[0037] (2) The present invention adopts bit plane processing based on information weight, and performs differential encryption on the upper 4-bit and lower 4-bit planes, effectively taking into account the security and efficiency performance of the encryption method.

[0038] (3) The encryption key is obtained by generating a feature value associated with the plaintext through a hash function, thereby generating a corresponding encryption sequence, and cross-iteration diffusion is performed during the encryption process to improve the encryption system's ability to resist plaintext attacks.

[0039] (4) The quantum logistic mapping adopted in the present invention not only has improved non-periodicity and randomness, but also has more initial values ​​and control parameters and a larger key space. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0041] Figure 1 This is a flow chart of an image encryption method based on RNA extended coding and quantum chaos according to an embodiment of the present invention;

[0042] Figure 2 Schematic diagram of a block replacement process according to an embodiment of the present invention;

[0043] Figure 3 A schematic diagram of a block rotation process according to an embodiment of the present invention;

[0044] Figure 4 This is a flowchart of RNA extended dynamic encoding encryption according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0047] This paper proposes a novel digital color image encryption method based on RNA extended dynamic coding and quantum chaos. By introducing more complex RNA coding rules, this method significantly enhances the encryption system's ability to resist cryptographic attacks. First, the method decomposes the plaintext image into bit planes, deriving the upper 4-bit and lower 4-bit components based on information weighting. The upper 4-bit plane is then scrambled in blocks and obfuscated using RNA extended coding rules. Simultaneously, a lightweight XOR operation is used on the lower 4-bit plane to improve encryption efficiency. Finally, the processed upper 4-bit and lower 4-bit planes undergo cross-iterative diffusion, ultimately synthesizing the resulting color ciphertext image. Simulation experiments and security analysis results demonstrate that the encryption algorithm exhibits excellent numerical statistical results and, according to cryptanalysis criteria, effectively resists known-plaintext and chosen-plaintext attacks. Therefore, the encryption algorithm proposed in this paper is a preferred technology for digital image privacy protection and has broad application prospects in multimedia secure communications on next-generation networks.

[0048] This paper proposes a digital image encryption method based on RNA extended dynamic coding. First, the color plaintext image is decomposed into two parts: the upper 4-bit plane and the lower 4-bit plane, depending on the information weight. Secondly, a hash function is used to generate a key associated with the plaintext image. This key is used as the input of a chaotic system to generate a chaotic sequence, which is used to perform block scrambling and RNA dynamic coding on the upper 4-bit plane. The chaotic sequence is then used to perform a lightweight exclusive-or operation on the lower 4-bit plane. Finally, the upper and lower 4-bit planes are cross-iteratively diffused and synthesized to obtain the color ciphertext image.

[0049] The above technical solution is described in detail:

[0050] The present invention relates to quantum logistic mapping and RNA extension coding rules and operation rules as follows:

[0051] Quantum logistic mapping:

[0052] Chaotic systems are often used in image processing due to their high sensitivity and randomness. One-dimensional chaotic systems have simple structures, and the resulting trajectory is easily predictable. The traditional Logistic Chaotic Map formula is as follows:

[0053]

[0054] Among them, the control parameters , system status value .

[0055] The recoil rotor model is used to quantize the classical logistic chaotic system, generating a corresponding quantum logistic map. This chaotic map adds a control parameter and has a fixed, non-vanishing correction variable at the end, which improves the non-periodicity and randomness of the quantum logistic chaotic map. The expression of this chaotic map is:

[0056]

[0057] in, is an adjustable parameter, is the dissipation parameter, 、 、 is the system status value; 、 They are 、 The complex conjugate of the system parameter. , , status value , , The system is in a chaotic state.

[0058] RNA extension dynamic encoding:

[0059] RNA is a long chain of ribonucleotides condensed through phosphodiester bonds. A ribonucleotide molecule is composed of phosphate, ribose, and bases. In RNA, there are four types of bases: A (adenine), G (guanine), C (cytosine), and U (uracil), with AU and CG forming complementary base pairs. To enhance the randomness of encryption, four new bases, M, N, S, and W, were added to the existing bases. These new bases follow specific pairing rules: M pairs with W, and S pairs with N. Furthermore, in binary, 0 and 1 are complementary, so 000-111, 001-110, 010-101, and 011-100 are also complementary. There are 384 encoding rules for encoding numbers using base pairs, as shown in Table 1, which greatly enhances the randomness of the matching. The above encoding rules are formed by permutations and combinations based on the above base pair complementarity and binary complementarity. For binary digits, there are 384 corresponding base arrangements, which are corresponded to each base arrangement of the binary digits by rule numbering, and are used for subsequent RNA encoding. In the process of image encryption and decryption, the relationship between the rule number and the binary digit corresponding to the rule number and the base is fixed and no longer changes. Operations between bases are realized by addition tables, subtraction tables or XOR tables, as shown in Table 2, Table 3 and Table 4 respectively. For the above different operation methods, the above different operation methods are also numbered and determined, and the corresponding operation method is selected by selecting the number corresponding to the operation method. Table 1 is the RNA extended encoding rule, Table 2 is the RNA extended addition operation, Table 3 is the RNA extended subtraction operation, and Table 4 is the RNA extended XOR operation.

[0060] Table 1

[0061] rule 1 2 3 4 5 6 7 8 …… 384 000 A A A A U A A A …… U 001 C C C G C C C C …… G 010 M M W M M S S N …… W 011 S N S S S M W M …… N 100 N S N N N W M W …… S 101 W W M W W N N S …… M 110 G G G C G G G G …… C 111 U U U U A U U U …… A

[0062] Table 2

[0063] + A C M S N W G U A U A C M S N W G C A C M S N W G U M C M S N W G U A S M S N W G U A C N S N W G U A C M W N W G U A C M S G W G U A C M S N U G U A C M S N W

[0064] Table 3

[0065] - A C M S N W G U A C M S N W G U A C A C M S N W G U M U A C M S N W G S G U A C M S N W N W G U A C M S N W N W G U A C M S G S N W G U A C M U M S N W G U A C

[0066] Table 4

[0067] ⊕ A C M S N W G U A W N U G C A S M C N W G U A C M S M U G W N S M C A S G U N W M S A C N C A S M W N U G W A C M S N W G U G S M C A U G W N U M S A C G U N W

[0068] The encryption method provided by the present invention is described in detail through the following technical solutions:

[0069] like Figure 1As shown, the method provided by the present invention is based on the following three parts: the first part is key generation. A hash function is used to generate a key associated with the plaintext. The second part is the image encryption process. The specific encryption process is divided into two modules. The first module is the encryption of the upper 4-bit plane after pixel value segmentation, and the second module is the cross-iterative diffusion of the upper 4-bit plane and the lower 4-bit plane of the pixel value. The third part is the image decryption process, which is the inverse operation of the encryption process.

[0070] Part 1, key generation:

[0071] Obtain a plaintext image, which is used as the information to be encrypted. By reading the pixel values ​​of the plaintext image, the read data is used as the input value of the SHA-256 hash function, and a fixed 256-bit binary number is output. Converting every 8 bits of the 256-bit binary number into a decimal number, 32 decimal numbers can be obtained. Each decimal number, i.e. the initial encoded information, can be expressed as ,in The key is generated as follows:

[0072]

[0073] in, Indicates XOR operation, key label , 、 、 、 、 For a given initial value, 、 、 、 、 is the key of the quantum logistic mapping system.

[0074] Part 2: Image encryption process:

[0075] Taking the three-dimensional matrix P of an image of size M×N×3 as an example, where M represents the image length dimension, N represents the image width dimension, and 3 represents the channel dimension (RGB), the specific encryption process is described as follows.

[0076] Sequence generation and preprocessing:

[0077] The key 、 、 、 、 As the input parameter of the chaos equation (Formula 3), a pseudo-random sequence is generated , , , , , , , , and then transform the pseudo-random sequence to obtain the sequence required for final encryption. , , , , , , , , and the corresponding sequence lengths are , , , , , , , . The specific operations are as follows:

[0078]

[0079] Among them, S y represents the y-th pseudo-random sequence, represents the y-th sequence required for encryption, and is subsequently characterized as the y-th sequence. Here, y is expressed as a noun in Chinese numeral writing, such as "the first sequence", representing the 1st sequence required for encryption, and the sequence index y = [1, 2,..., 8]. represents the floor function, represents the modulo operation function.

[0080] For high 4-bit plane encryption:

[0081] Step 1, bit decomposition:

[0082] Represent each pixel value in matrix P with an 8-bit binary number, extract the first 4 binary numbers of all pixel values, and then perform bit-level decomposition to form a three-dimensional matrix with a size of M×N×12, that is, the first high-bit matrix , and extract the last 4 binary numbers to form a three-dimensional matrix with a size of , that is, the first low-bit matrix .

[0083] Among them, bit decomposition converts the pixel values of decimal numbers between [0, 255] in different channel dimensions into 8-bit binary numbers. Among them, the first four bits, that is, the high four bits, contain more information and have a higher information weight.

[0084] Step 2, block scrambling:

[0085] For the first high-bit matrix Divide the matrix into blocks, each sub-matrix has a size of 4×4×4, and then reassemble the sub-matrices into a row in sequence to obtain a sub-matrix sequence ,order , through the first sequence Pair matrix sequence Perform the replacement. The operation is as follows:

[0086]

[0087] in is an intermediate variable. Then the sub-matrix sequence is reorganized into a matrix in order Taking an 8×8×8 matrix as an example, the specific block permutation flow chart is as follows Figure 2 In this scheme, an M×N×3 matrix can be converted into an M×N×12 matrix by bit decomposition and taking the high 4 bits. Since the size of each sub-matrix is ​​4×4×4, there are M×N×12 / (4×4×4)=M×N×3 / 16 sub-matrices. For the convenience of demonstration, it is not shown in the M×N×12 matrix, but in the 8×8×8 matrix for exemplary demonstration. Figure 2 In the example, the matrix size is 8×8×8, so there are 8×8×8 / (4×4×4)=8 sub-matrices in total. For example, S1'=[3,7,2,6,5,1,8,4]. When S1'(1)=3, that is, the first sub-matrix and the third sub-matrix are swapped in position during the first permutation to obtain a new sub-matrix sequence. S1'(2)=7, that is, the second sub-matrix and the seventh sub-matrix are swapped during the second permutation, and so on.

[0088] Rotate the submatrix after block permutation, and pass the second sequence Determine the number of times each submatrix is ​​rotated 90 degrees counterclockwise around the three axes to obtain the second highest bit matrix after rotation Taking the rotation of a 4×4×4 submatrix as an example, the top, front and rightmost vertices of the initial submatrix are used as the rotation centers. The specific block rotation flow chart is as follows: Figure 3 shown.

[0089] Finally, go through the third sequence For the second highest bit matrix Invert it to get the third highest bit matrix after inversion The specific inversion operation is as follows:

[0090]

[0091] Among them, the pixel index .

[0092] Step 3: RNA expansion dynamic coding diffusion:

[0093] The third highest bit matrix From bottom to top, every 3 binary numbers are combined into an octal number, according to the fifth sequence The first half (the first 4MN bits) of the image is encoded, and then each octal number (each pixel) is encoded to obtain a matrix of size M×N×4, which is the fourth high-bit matrix. . Use the reshape function to transform the sixth sequence Reorganized into a two-dimensional matrix of size M×N, the encoding method of the reorganized sixth sequence matrix is ​​the same as that of the fourth high-bit matrix The encoding method of the corresponding position of the first layer is the same, and the third sub-matrix is ​​obtained after encoding . Using the fourth sequence Select from three operations: addition, subtraction, and XOR, and then combine the third sub-matrix , for the fourth highest bit matrix Perform iterative diffusion, each octal number (each pixel) has a corresponding operation method, and the fifth high-bit matrix is ​​obtained The specific diffusion operation is as follows:

[0094]

[0095] in, Indicates the number of layers and image length label , image width label , Indicates addition, subtraction or XOR operation. The specific operation method is determined by the fourth sequence control.

[0096] Step 4: RNA expansion dynamic code shift:

[0097] For the fifth highest bit matrix , according to the fifth sequence The corresponding encoding rule is to right-shift the next row according to the last pixel value of the previous row, and convert the fifth high bit matrix The last pixel value of each row and the rightmost pixel value are shifted to the leftmost side to form a regular matrix, and the sixth high-bit matrix after the shift is obtained. . Pass the fifth sequence The second half of the encoding method is selected for decoding, and the decoded sixth high bit matrix From bottom to top, every 4 bits are synthesized into a pixel value, and the size is The three-dimensional matrix is ​​the seventh high-bit matrix The RNA extended coding encryption flow chart is as follows: Figure 4 The specific shift operation is as follows:

[0098]

[0099] in, Indicates the number of layers, , Indicates the The last pixel value of the row, Indicates the The last pixel value of the row, is an intermediate variable.

[0100] Cross-iterative diffusion for the upper 4-bit plane and the lower 4-bit plane:

[0101] The seventh high bit matrix , the first low-bit matrix Reassemble into high bit reassembly vector , low bit reassembly vector , using the seventh sequence Recombination vector with low bit XOR to get the vector after XOR calculation , using the eighth sequence For two vectors (high bit reorganization vector and XORed vector ) perform addition and modulo operation, and finally synthesize the pixel values ​​to obtain the final encrypted matrix C. The following is the algorithm flow of pixel value cross-iterative diffusion:

[0102] Step 1: Convert the matrix and Convert to length One-dimensional sequence and ;

[0103] Step 2: and XOR ;

[0104] Step 3: If , do the following:

[0105]

[0106] if , do the following:

[0107]

[0108] Step 4: If , do the following:

[0109]

[0110] if , do the following:

[0111]

[0112] Step 5: and Convert to size The three-dimensional matrix and ;

[0113] Step 6: Obtain the ciphertext image C through the following equation:

[0114]

[0115] The range of w is 1 to 3MN (the number of sequence elements), that is, the w-th element of the sequence is taken for operation, and the range of q is 1 to 3MN (the number of sequence elements), that is, the q-th element of the sequence is taken for operation.

[0116] Part 3: Image decryption:

[0117] The decryption process is the inverse of the encryption process. Before decrypting an image, the key must be transmitted to the decryption end via a secure channel. During the image encryption phase, the image is first segmented by pixel value, then the upper and lower 4-bit planes are encrypted separately, and finally these are cross-iteratively diffused to synthesize the pixel values. Therefore, during the decryption phase, the pixel value segmentation must be performed first, followed by reverse iterative diffusion of the two segmented matrices, and then decrypted separately to finally synthesize the plaintext.

[0118] This paper proposes a digital image encryption algorithm based on RNA extended dynamic coding. In this algorithm, a color plaintext image is decomposed into bit planes. The upper and lower 4-bit planes are encrypted with varying degrees of complexity based on information weight. Cross-iterative diffusion is then performed and finally synthesized to produce a color ciphertext image. RNA extended dynamic coding is used to encrypt the upper 4-bit plane, which not only improves encryption efficiency but also significantly enhances the encryption system's resistance to cryptographic attacks. Furthermore, cross-iterative diffusion between the upper and lower 4-bit planes further obfuscates the encrypted information, significantly increasing the difficulty for attackers to crack it. Experimental results demonstrate that this encryption scheme not only exhibits excellent robustness but also boasts a large key space sufficient to resist various brute-force attacks. Future research will further explore the potential application of this algorithm in other fields, such as video and audio. Furthermore, we will conduct a deeper security analysis of the algorithm's performance and embed the encryption system into practical applications to more comprehensively evaluate its performance in real-world scenarios.

[0119] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. An image encryption method based on RNA extended coding and quantum chaos, characterized in that: include: Obtaining a plaintext image, encoding the plaintext image to obtain initial encoding information, and generating a key based on the initial encoding information; A pseudo-random sequence is calculated using a chaotic equation according to the key, and the pseudo-random sequence is transformed to obtain the sequence required for encryption; Obtain a three-dimensional matrix of a plaintext image, decompose the three-dimensional matrix into a first high-bit matrix and a first low-bit matrix, perform block scrambling and RNA dynamic encoding on the first high-bit matrix according to the sequence required for encryption, perform XOR calculation on the first low-bit matrix according to the sequence required for encryption, cross-iteratively diffuse and synthesize the matrix after RNA dynamic encoding and the matrix obtained by XOR calculation to obtain a color ciphertext image.

2. The method according to claim 1, characterized in that The pixel values ​​in the plaintext image are calculated using the SHA-256 hash function, and the SHA-256 hash function calculation results are converted into decimal numbers every 8 to obtain the initial encoded information.

3. The method according to claim 1, characterized in that The key generation process includes: ； in, Represents the initial coding information, subscript j represents the initial coding information corresponding to the j-th pixel, , Indicates XOR operation, key label , 、 、 、 and Give the key an initial value, 、 、 、 and is the key of the quantum logistic mapping system, where 、 、 represents the system state value of the corresponding quantum logistic mapping system, is an adjustable parameter, represents the dissipation parameter.

4. The method according to claim 1, wherein The process of generating the sequence required for encryption includes: ； Among them, S y represents the yth pseudo-random sequence, Indicates the sequence required for the yth encryption, the sequence index y=[1,2,...,8], represents the floor function, Represents the modular arithmetic function.

5. The method according to claim 1, characterized in that The process of decomposing a three-dimensional matrix includes: Each pixel value in the three-dimensional matrix is ​​represented by an 8-bit binary number, the first 4 binary bits of all pixel values ​​are extracted, the extracted results are bit-level decomposition to generate a first high-bit matrix, and the last 4 binary bits of all pixel values ​​are extracted to generate a first low-bit matrix.

6. The method according to claim 4, characterized in that The process of performing block scrambling on the first high-bit matrix includes: Performing fixed-size block division on the first high-bit matrix to obtain submatrices, sequentially reorganizing the submatrices into a row to obtain a submatrix sequence, permuting the submatrix sequence according to the first sequence, reorganizing the submatrix according to the permuted sequence to obtain a reorganized first high-bit matrix, rotating the reorganized first high-bit matrix according to a second sequence, wherein information in the second sequence points to different rotation directions and a fixed number of rotations to obtain a second high-bit matrix, and inverting the second high-bit matrix according to a third sequence to obtain a third high-bit matrix, i.e., a block-scrambled matrix; The first sequence, the second sequence and the third sequence are respectively the first encryption required sequence, the second encryption required sequence and the third encryption required sequence.

7. The method according to claim 4, characterized in that The process of RNA dynamic encoding includes: For the block-scrambled matrix, for each element, every three binary digits are combined into an octal number from top to bottom. A coding rule is selected based on the first half of the fifth sequence, and each octal number is encoded according to the selected coding rule to obtain a fourth high-bit matrix. The coding rule includes a correspondence between octal numbers and RNA bases under different rules. Under each rule, each octal number corresponds to only one base, and when the octal numbers are complementary, the bases are also complementary. Reorganize the sixth sequence into a two-dimensional matrix with the same length and width dimensions as the plaintext image, and encode the reorganized sixth sequence according to the selected encoding rule to obtain a third sub-matrix; selecting an operation mode according to a fourth sequence, wherein the operation mode includes addition, subtraction, and exclusive-or; performing iterative diffusion on the fourth high-bit matrix and the third submatrix according to the selected operation mode to obtain a fifth high-bit matrix; In the iterative diffusion, the first-layer matrix of the fourth high-bit matrix and the third submatrix are operated using the selected operation method to obtain the first-layer matrix of the fifth high-bit matrix, and then the k-1-th layer matrix of the fifth high-bit matrix and the k-th layer matrix of the fourth high-bit matrix are operated using the selected operation method to obtain the k-th layer matrix of the fifth high-bit matrix; According to the selected coding rule, the pixel value of the last pixel in each row of the fifth high-bit matrix is ​​obtained, and the pixels in the next row are shifted according to the pixel value of the last pixel in each row. For the shifted matrix, the last pixel and the pixel to the right of each row of the fifth high-bit matrix are shifted to the leftmost side of the same row to form a regular matrix, thereby obtaining a sixth high-bit matrix; Selecting a coding rule based on the second half of the fifth sequence, decoding the sixth high-bit matrix according to the newly selected coding rule, and synthesizing the decoded sixth high-bit matrix from top to bottom, with every 4 bits forming a pixel value, to obtain the seventh high-bit matrix, which is the matrix after RNA dynamic encoding; Among them, the fourth sequence, the fifth sequence and the sixth sequence are respectively the fourth encryption required sequence, the fifth encryption required sequence and the sixth encryption required sequence.

8. The method according to claim 4, characterized in that The process of obtaining a color ciphertext image includes: Recombining the RNA dynamically encoded matrix and the first low-bit matrix to obtain a high-bit recombined vector and a low-bit recombined vector, and performing an XOR calculation on the low-bit recombined vector using the seventh sequence; According to the eighth sequence, the matrix obtained by the XOR calculation and the high-bit reorganized vector are respectively subjected to an addition modulo operation, and pixel values ​​of the addition modulo operation results are synthesized to obtain a color ciphertext image.

9. The method according to claim 1, characterized in that After obtaining the color ciphertext image, it also includes: The key is transmitted and obtained, the pixel value of the color ciphertext image is segmented, the segmented matrix is ​​reversely iterated and diffused, the sequence required for encryption is obtained according to the key, and the encryption process is reversed according to the required encryption sequence to obtain the plaintext image.

10. Image encryption system based on RNA extended coding and quantum chaos, characterized by: Used to execute the method according to any one of claims 1 to 9.

Images