Image diffusion method based on tetragonal cipher and dynamic DNA coding

Abstract

The invention discloses an image diffusion method based on a tetragonal password and dynamic DNA coding, and belongs to the field of information encryption. At present, along with rapid development of technologies such as big data, cloud computing and artificial intelligence, data image security faces new challenges, and image security problems become more and more important. In order to improve and ensure the security of an image in a transmission process, the invention provides an image diffusion method based on a tetragonal password and dynamic DNA coding. The method comprises the following steps: firstly, performing dynamic DNA coding on an original image, and converting the original image into a DNA matrix; secondly, performing square password diffusion on the DNA matrix; and finally, performing dynamic DNA decoding on the diffusion result to generate an encrypted image. Experimental results and method analysis show that the method is high in safety and efficient, and information leakage of images in the network transmission process can be effectively prevented.

Description

Technical Field

[0001] The present invention relates to an information encryption technology, in particular to an image encryption method. Background Art

[0002] In modern society, images, as an important form of information transmission, have been widely used in many fields such as social media, medical imaging and video surveillance. With the advancement of digitalization, the confidentiality and integrity of image data have become increasingly important. The widespread dissemination of image data has also brought about information security issues. Unencrypted images may be maliciously accessed, tampered with or forged, affecting privacy protection and data reliability. Therefore, information security research is one of the most important topics in today's era, and it is necessary to continuously invest resources and energy to solve related problems and protect the information security of individuals, enterprises and the country.

[0003] Image encryption methods include chaos-based encryption, DNA-based encryption, compressed sensing-based image encryption, etc. Among them, the DNA-based image encryption algorithm is a new type of image encryption method.

[0004] In order to improve and ensure the security of images during transmission, an image diffusion method based on four-party password and dynamic DNA coding is proposed. This method combines the four-party password theory and performs dynamic DNA coding on images, which can improve the security of images and effectively prevent images from being attacked and information leaked. Summary of the invention

[0005] The purpose of the present invention is to protect the security of data images and improve and ensure the security of images during transmission. An image diffusion method based on four-party password and dynamic DNA coding is proposed.

[0006] Technical solution of the present invention: To achieve the above-mentioned invention purpose, the technical solution adopted is to propose an image diffusion method based on four-party password and dynamic DNA coding. The encryption steps are described in detail as follows: Step 1: Generate chaotic sequence: Let the original image be P , the size is m × n ; The exponential sine cube map is: x t = a × e sin(b) ×[1- e 2sin(b) ] mod 1, (1) in, b = x t-1 , a >0.17 is the control parameter,x t ∈(0, 1), mod (•) represents modulo operation; randomly select control parameters a 1 , a 2 and initial value x 0 , y 0 , respectively iterate formula (1) mn times, we can get two lengths of mn Chaotic sequence S 1 and S 2 ; Randomly select control parameters a 3 , a 4 , a 5 and initial value z 0 , u 0 , v 0 , respectively iterate formula (1) 2 mn times, we can get 3 numbers with the same length of 2 mn Chaotic sequence S 3 , S 4 and S 5 ; Step 2: Integerization of chaotic sequence: Using formulas (2)-(6), S 1 , S 2 , S 3 , S 4 and S 5 To perform integer processing, S 6 = mod [ floor ( S 1 ×10 15 ), 8]+1, (2) S 7 = mod [ floor ( S 2 ×10 15), 8]+1, (3) S 8 = mod [ floor ( S 3 ×10 15 ), 24]+1, (4) S 9 = mod [ floor ( S 4 ×10 15 ), 24]+1, (5) S 10 = mod [ floor ( S 5 ×10 15 ), 24]+1, (6) in, floor (•) is the floor function, S 6 and S 7 The lengths of both mn An integer chaotic sequence of S 8 , S 9 and S 10 There are 3 lengths of 2 mn Integer chaotic sequence of ; Step 3: Dynamic DNA encoding: From left to right and from top to bottom, P Converted to 1 length mn Vector S P ; Use the S 6 ( i )∈ S 6 DNA encoding rules for pixel values S P ( i ) for dynamic DNA encoding, i =1, 2, ..., mn , we can get a size of mn ×4 DNA Matrix M 1; Among them, there are 8 DNA coding rules, which are specifically described as shown in the following table: the first rule is to encode 00, 01, 10, 11 as A, G, C, T respectively; the second rule is to encode 00, 01, 10, 11 as A, C, G, T respectively; the third rule is to encode 00, 01, 10, 11 as T, G, C, A respectively; the fourth rule is to encode 00, 01, 10, 11 as T, C, G, A respectively; the fifth rule is to encode 00, 01, 10, 11 as C, T, A, G respectively; the sixth rule is to encode 00, 01, 10, 11 as C, A, T, G respectively; the seventh rule is to encode 00, 01, 10, 11 as G, T, A, C respectively; the eighth rule is to encode 00, 01, 10, 11 as G, A, T, C respectively;

[0007] Step 4: Generate base code matrix and sequence matrix: Use S 8 ( j )∈ S 8 , S 9 ( j )∈ S 9 and S 10 ( j )∈ S 10 , randomly select three non-repeating four-base matrix arrangements as base code matrices of size 2×2 D 1j , base code matrix D 2j and the order matrix S j , j =1, 2, ..., 2 mn; Among them, there are 24 non-repeating four-base matrix arrangements, as shown in the following table, specifically described as: the first arrangement is ACGT, the second arrangement is ACTG, the third arrangement is AGCT, the fourth arrangement is AGTC, the fifth arrangement is ATCG, the sixth arrangement is ATGC, the seventh arrangement is CAGT, the eighth arrangement is CATG, the ninth arrangement is CGAT, the tenth arrangement is CGTA, the eleventh arrangement is CTAG, the twelfth arrangement is CTGA, the thirteenth arrangement is GACT, the fourteenth arrangement is GATC, the fifteenth arrangement is GCAT, the sixteenth arrangement is GCTA, the seventeenth arrangement is GTAC, the eighteenth arrangement is GTCA, the nineteenth arrangement is TACG, the twentieth arrangement is TAGC, the twenty-first arrangement is TCAG, the twenty-second arrangement is TCGA, the twenty-third arrangement is TGAC, and the twenty-fourth arrangement is TGCA;

[0008] Step 5: Four-way password diffusion: Using formula (7), combine D 1j , D 2j and S j Constitute a 4×4 large base matrix D j , D j =[ S j , D 2j ; D 1j , S j ], j =1, 2, ..., 2 mn ; (7) Select M 1 Two adjacent bases in p 1 and p 2 ,exist D j The upper left 2×2 submatrix D j In (1:2, 1:2), find the element value is p 1 The coordinate position of x D1 , y D1 );exist D jThe 2×2 submatrix in the lower right corner D j In (3:4, 3:4), find the element value is p 2 The coordinate position of x D2 , y D2 );exist D j The 2×2 submatrix in the upper right corner D j (1:2, 3:4), select the coordinate position as ( x D1 , y D2 ) c 1 As p 1 The corresponding ciphertext base; D j The 2×2 submatrix in the lower left corner D j (3:4,1:2), select the coordinate position as ( x D2 , y D1 ) c 2 As p 2 The corresponding ciphertext bases; encrypted in sequence M 1 All bases in can be obtained as 1 mn ×4 DNA Matrix M 2 ; Step 6: Dynamic DNA decoding: Using the S 7 ( i )∈ S 7 DNA decoding rules for M 2 ( i ) for dynamic DNA decoding, i =1, 2, ..., mn , we can get a size of m × n Encrypted image of C; Among them, there are 8 DNA decoding rules, which are specifically described as shown in the following table: the first rule is to decode A, G, C, and T as 00, 01, 10, and 11 respectively; the second rule is to decode A, C, G, and T as 00, 01, 10, and 11 respectively; the third rule is to decode T, G, C, and A as 00, 01, 10, and 11 respectively; the fourth rule is to decode T, C, G, and A as 00, 01, 10, and 11 respectively; the fifth rule is to decode C, T, A, and G as 00, 01, 10, and 11 respectively; the sixth rule is to decode C, A, T, and G as 00, 01, 10, and 11 respectively; the seventh rule is to decode G, T, A, and C as 00, 01, 10, and 11 respectively; the eighth rule is to decode G, A, T, and C as 00, 01, 10, and 11 respectively.

[0009]

[0010] During the decryption process, the same chaotic sequence is used to encrypt the image. C Perform decryption to restore the plaintext image P , the decryption process is the reverse process of encryption.

[0011] Beneficial effects: In order to protect image information and improve and ensure the security of images during transmission, an image diffusion method based on four-party password and dynamic DNA coding is proposed. The main contributions are as follows: (1) Dynamic DNA four-party matrix coding is defined, and dynamic DNA coding is organically combined with four-party password; (2) An image diffusion method based on four-party password and dynamic DNA coding is proposed; (3) Experimental results and algorithm analysis verify the feasibility and security of the proposed method, which can realize the network transmission and storage security of image information. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 : Encryption flow chart; Figure 2 : original image; Figure 3 : Dynamic DNA quadrilateral matrix encoding flow chart; Figure 4 : Encrypted image. DETAILED DESCRIPTION

[0013] The implementation process of the present invention is further described in detail below with reference to specific drawings and examples.

[0014] Figure 1 It is the encryption flow chart of this method.

[0015] The programming software used was Matlab R2023b, and the public database USC-SIPI (http: / / sipi.usc.edu / database) was selected. Figure 2 The Boat grayscale image with a size of 512 × 512 is shown as the original image. The encryption process of the original image is described in detail as follows using the proposed image diffusion method based on the four-party cipher and dynamic DNA coding.

[0016] Step 1: Generate chaotic sequence: Let the original image be P , the size is 512 × 512； Random Selection a 1 , a 2 and initial value x 0 , y 0 , iterate formula (1) 262144 times, and get two chaotic sequences with lengths of 262144 S 1 and S 2 ; Randomly select control parameters a 3 , a 4 , a 5 and initial value z 0 , u 0 , v 0 , iterate formula (1) 524288 times respectively, and get three chaotic sequences with the same length of 524288 S 3 , S 4 and S 5 .

[0017] Step 2: Integerization of chaotic sequence: Using formulas (2)-(6), S 1 , S 2 , S 3 , S 4 and S 5 After integer processing, we can get two integer chaotic sequences with lengths of 262144 respectively. S 6 , S7 , 3 integer chaotic sequences of length 524288 S 8 , S 9 and S 10 .

[0018] Step 3: Dynamic DNA encoding: From left to right and from top to bottom, P Converted into a vector of length 262144 S P ; Use the S 6 ( i )∈ S 6 DNA encoding rules for pixel values S P ( i ) for dynamic DNA encoding, i =1,2, ..., 262144, we get a DNA matrix of size 262144×4 M 1 .

[0019] Step 4: Generate base code matrix and sequence matrix: Use S 8 ( j )∈ S 8 , S 9 ( j )∈ S 9 and S 10 ( j )∈ S 10 , randomly select three non-repeating four-base matrix arrangements as base code matrices of size 2×2 D 1j , base code matrix D 2j and the order matrix S j , j =1, 2, ..., 524288.

[0020] Step 5: Four-way password diffusion: Using formula (7), combine D 1j , D 2j and S j Constitute a 4×4 large base matrix Dj , j =1, 2, ..., 524288 ； Then in turn M 1 The two adjacent bases in the four-way cryptographic diffusion are encrypted in sequence. M 1 All bases in can be obtained as a DNA matrix of size 262144×4 M 2 ,like Figure 3 shown.

[0021] Step 6: Dynamic DNA decoding: Using the S 7 ( i )∈ S 7 DNA decoding rules for M 2 ( i ) for dynamic DNA decoding, i =1, 2, ..., 262144, we get a size of 512 × 512 Encrypted image of C ,like Figure 4 shown.

[0022] During the decryption process, the same chaotic sequence is used to encrypt the image. C Perform decryption to restore the plaintext image P , the decryption process is the reverse process of encryption.

Claims

1. The image diffusion method based on the four-party password and dynamic DNA coding is characterized by: The diffusion process includes the following steps: Step 1: Generate chaotic sequence: Let the original image be P , the size is m × n ; The exponential sine cube map is: x t = a × e sin(b) ×[1- e 2sin(b) ] mod 1， （1） in, b = x t-1 , a >0.17 is the control parameter, x t ∈(0, 1), mod (•) represents modulo operation; randomly select control parameters a 1. a 2 and initial value x 0. y 0, respectively iterate formula (1) mn times, we can get two lengths of mn Chaotic sequence S 1 and S 2. Randomly select control parameters a 3. a 4. a 5 and initial value z 0. u 0. v 0, iterate formula (1) 2 times mn times, we can get 3 numbers with the same length of 2 mn Chaotic sequence S 3. S 4 and S 5; Step 2: Integerization of chaotic sequence: Using formulas (2)-(6), S 1. S 2. S 3. S 4 and S 5 is integerized. S 6= mod [ floor ( S 1×10 15 ), 8]+1， （2） S 7= mod [ floor ( S 2×10 15 ), 8]+1， （3） S 8= mod [ floor ( S 3×10 15 ), 24]+1， （4） S 9= mod [ floor ( S 4×10 15 ), 24]+1， （5） S 10 = mod [ floor ( S 5×10 15 ), 24]+1， （6） in, floor (•) is the floor function, S 6 and S 7 is the length of both mn An integer chaotic sequence of S 8. S 9 and S 10 There are 3 lengths of 2 mn Integer chaotic sequence of ; Step 3: Dynamic DNA encoding: From left to right and from top to bottom, P Converted to 1 length mn Vector S P ; Use the S 6( i )∈ S 6 DNA encoding rules for pixel values S P ( i ) for dynamic DNA encoding, i =1, 2, ..., mn , we can get a size of mn ×4 DNA Matrix M 1; Among them, there are 8 DNA coding rules: the first rule is to encode 00, 01, 10, 11 as A, G, C, T respectively; the second rule is to encode 00, 01, 10, 11 as A, C, G, T respectively; the third rule is to encode 00, 01, 10, 11 as T, G, C, A respectively; the fourth rule is to encode 00, 01, 10, 11 as T, C, G, A respectively; the fifth rule is to encode 00, 01, 10, 11 as C, T, A, G respectively; the sixth rule is to encode 00, 01, 10, 11 as C, A, T, G respectively; the seventh rule is to encode 00, 01, 10, 11 as G, T, A, C respectively; the eighth rule is to encode 00, 01, 10, 11 as G, A, T, C respectively; Step 4: Generate base code matrix and sequence matrix: Use S 8( j )∈ S 8. S 9( j )∈ S 9 and S 10 ( j )∈ S 10 , randomly select three non-repeating four-base matrix arrangements as base code matrices of size 2×2 D 1j , base code matrix D 2j and the order matrix S j , j =1, 2, ..., 2 mn ; Among them, there are 24 non-repeating four-base matrix arrangements: the first arrangement is ACGT, the second arrangement is ACTG, the third arrangement is AGCT, the fourth arrangement is AGTC, the fifth arrangement is ATCG, the sixth arrangement is ATGC, the seventh arrangement is CAGT, the eighth arrangement is CATG, the ninth arrangement is CGAT, the tenth arrangement is CGTA, the eleventh arrangement is CTAG, the twelfth arrangement is CTGA, the thirteenth arrangement is GACT, the fourteenth arrangement is GATC, the fifteenth arrangement is GCAT, the sixteenth arrangement is GCTA, the seventeenth arrangement is GTAC, the eighteenth arrangement is GTCA, the nineteenth arrangement is TACG, the twentieth arrangement is TAGC, the twenty-first arrangement is TCAG, the twenty-second arrangement is TCGA, the twenty-third arrangement is TGAC, and the twenty-fourth arrangement is TGCA; Step 5: Four-way password diffusion: Using formula (7), combine D 1j , D 2j and S j Constitute a 4×4 large base matrix D j ， D j =[ S j , D 2j ; D 1j , S j ]， j =1, 2, ..., 2 mn ； （7） Select M Two adjacent bases in 1 p 1 and p 2. In D j The upper left 2×2 submatrix D j In (1:2, 1:2), find the element value is p The coordinate position of 1 is recorded as ( x D1 , y D1 );exist D j The 2×2 submatrix in the lower right corner D j In (3:4, 3:4), find the element value is p 2, denoted as ( x D2 , y D2 );exist D j The 2×2 submatrix in the upper right corner D j (1:2, 3:4), select the coordinate position as ( x D1 , y D2 ) c 1 as p 1 corresponds to the ciphertext base; D j The 2×2 submatrix in the lower left corner D j (3:4, 1:2), select the coordinate position as ( x D2 , y D1 ) c 2 as p 2 corresponding ciphertext bases; encrypted in sequence M All bases in 1 can be obtained as 1 mn ×4 DNA Matrix M 2; Step 6: Dynamic DNA decoding: Using the S 7( i )∈ S 7 DNA decoding rules for M 2( i ) for dynamic DNA decoding, i =1,2, ..., mn , we can get a size of m × n Encrypted image of C ; Among them, there are 8 DNA decoding rules: the first rule is to decode A, G, C, and T as 00, 01, 10, and 11 respectively; the second rule is to decode A, C, G, and T as 00, 01, 10, and 11 respectively; the third rule is to decode T, G, C, and A as 00, 01, 10, and 11 respectively; the fourth rule is to decode T, C, G, and A as 00, 01, 10, and 11 respectively; the fifth rule is to decode C, T, A, and G as 00, 01, 10, and 11 respectively; the sixth rule is to decode C, A, T, and G as 00, 01, 10, and 11 respectively; the seventh rule is to decode G, T, A, and C as 00, 01, 10, and 11 respectively; the eighth rule is to decode G, A, T, and C as 00, 01, 10, and 11 respectively.

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