Image chaos tent mapping encryption method, system and device and storage medium

Abstract

The embodiment of the invention relates to the field of image processing, and discloses an image chaos tent mapping encryption method, system and device and a storage medium, and the method comprises the steps: decomposing a plaintext image to be encrypted, and obtaining a high-order plane group vector A1 and a low-order plane group vector A2; carrying out vector conversion processing on the high-order plane group vector A1 and the low-order plane group vector A2 to obtain an odd-number-bit-plane quantity group b1 and an even-number-bit-plane quantity group b2; based on the high-order plane group vector A1 and the low-order plane group vector A2, carrying out cyclic shift and XOR operation on a quantity group b1 and an even-order plane to form a diffusion sequence B1 and a diffusion sequence B2; performing n rounds of confusion processing on the diffusion sequence B1 and the diffusion sequence B2 to obtain a sequence C1 and a sequence C2; and performing bit plane merging operation on the sequence C1 and the sequence C2 to obtain an encrypted image. The method has good encryption performance and can be widely applied to the field of image transmission encryption communication.

Description

Technical Field

[0001] The disclosed embodiments relate to the field of image processing technology, and in particular to an image chaos tent mapping encryption method, system, device and storage medium in a civil aviation intelligent travel scenario. Background Art

[0002] Civil aviation passenger travel scenarios are gradually changing to intelligent travel, and it is particularly important to ensure the security of passenger information in intelligent travel scenarios. The facial information of civil aviation passengers must be collected, transmitted, stored, and used in the entire process to protect the personal privacy of passengers. Focusing on the security issues of image transmission in passenger intelligent travel scenarios, at present, the technologies to ensure the security of data transmission include cryptographic technology, federated learning, and privacy protection. Cryptographic technology is divided into cryptographic coding technology, cryptographic analysis technology, authentication technology, and key management technology. Key coding technology provides confidentiality protection for information to prevent eavesdropping and leakage, including symmetric cryptography and asymmetric cryptography. Encryption and decryption are the content of cryptography.

[0003] The current technology is to ensure the security of passengers' facial information by encrypting image information for cross-domain transmission. Because facial information is currently stored in two ways: formatted data and unformatted data. Unformatted data, namely image data, has some inherent characteristics, such as large size, high redundancy and strong correlation between adjacent pixels, which is different from general data. In addition, image data requires strong real-time communication, so a fast and highly secure encryption method is needed. Some traditional encryption algorithms such as DES, IDEA, AES, etc. are not suitable for image encryption. Since traditional block encryption technology cannot meet the requirements of image encryption, it is urgent to propose a digital image and data information encryption technology that uses chaotic mapping with high sensitivity to initial conditions, system parameter values ​​and simple structures to solve the problems faced by traditional technologies. Summary of the invention

[0004] The embodiments of the present disclosure provide an image chaotic tent mapping encryption method, system, device and storage medium to solve or alleviate one or more of the above technical problems in the prior art.

[0005] According to one aspect of the present disclosure, there is provided an image chaotic tent mapping encryption method, comprising: Decomposing the plaintext image to be encrypted to obtain a high-order face group vector A1 and a low-order face group vector A2; Performing vector conversion processing on the high-order surface group vector A1 and the low-order surface group vector A2 to obtain an odd-numbered surface vector group b1 and an even-numbered surface vector group b2; Performing cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-numbered plane vector group b1 and the even-numbered plane vector group b2 to form a diffusion sequence B1 and a diffusion sequence B2; Perform n rounds of obfuscation processing on the diffusion sequence B1 and the diffusion sequence B2 to obtain the sequence C1 and the sequence C2; The sequence C1 and the sequence C2 are combined by bit plane operation to obtain an encrypted image.

[0006] In a possible implementation, the plaintext image to be encrypted is decomposed to obtain the high-order face group vector A1 and the low-order face group vector A2, including: Decomposing the plaintext image to be encrypted into a high-order face group and a low-order face group; The high-order face group and the low-order face group are expanded respectively to obtain the high-order face group vector A1 and the low-order face group vector A2.

[0007] In a possible implementation, performing vector conversion processing on the high-order plane group vector A1 and the low-order plane group vector A2 to obtain an odd-order plane vector group b1 and an even-order plane vector group b2 includes: Use the key to perform tent-map mapping on the high-order face group vector A1 and the low-order face group vector A2 respectively, and iterate the target number of times to obtain the sequence , , represents the elements in the sequence X, Indicates the size of the image; Round the elements of sequence X to obtain integer sequence X1; Convert the integer sequence X1 to Type Matrix ; Will Type Matrix Decompose to form odd-numbered planes and even-numbered planes; The odd bit planes and the even bit planes are expanded into an odd bit plane vector group b1 and an even bit plane vector group b2 respectively.

[0008] In a possible implementation, performing cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-order plane vector group b1, and the even-order plane vector group b2 to form the diffusion sequence B1 and the diffusion sequence B2 includes: Calculate the sum of the elements of the low-order face group vector A2 ; Circularly shift the high-order face group vector A1 to the right bits, and we get vector A 11 ; Vector A 11, perform an XOR operation on the low-order face group vector A2 and the odd-order face group vector b1 to obtain a diffusion sequence B1 of the high-order face group vector A1; Calculate the sum of the elements of vector B1 ; Circularly right shift the low-order face group vector A2 Get vector A 22 ; Vector A 22 , vector B1 and the even-bit plane vector group b2 are XORed to obtain the diffusion sequence B2 of the low-bit plane group vector A2.

[0009] According to one aspect of the present disclosure, there is provided an image chaotic tent mapping encryption system, comprising: a decomposition unit, for decomposing a plaintext image to be encrypted to obtain a high-order face group vector A1 and a low-order face group vector A2; A conversion unit, used for performing vector conversion processing on the high-order surface group vector A1 and the low-order surface group vector A2 to obtain an odd-numbered surface vector group b1 and an even-numbered surface vector group b2; A diffusion unit, configured to perform cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-numbered plane vector group b1, and the even-numbered plane vector group b2 to form a diffusion sequence B1 and a diffusion sequence B2; A confusion unit, used for performing n rounds of confusion processing on the diffusion sequence B1 and the diffusion sequence B2 to obtain the sequence C1 and the sequence C2; The bit plane combination unit is used to perform a bit plane operation on the sequence C1 and the sequence C2 to obtain an encrypted image.

[0010] In a possible implementation, the decomposition unit includes: A first decomposition module is used to decompose the plaintext image to be encrypted to form a high-order surface group and a low-order surface group; The first expansion module is used to expand the high-order surface group and the low-order surface group respectively to obtain the high-order surface group vector A1 and the low-order surface group vector A2.

[0011] In a possible implementation, the conversion unit includes: A mapping module is used to use the key to perform tent-map mapping on the high-order face group vector A1 and the low-order face group vector A2 respectively, and iterate the target number of times to obtain the sequence , , represents the elements in the sequence X, Indicates the size of the image; The rounding module is used to round the elements of the sequence X to obtain an integer sequence X1; Transformation module, used to transform the integer sequence X1 into Type Matrix ; The second decomposition module is used to Type Matrix Decompose to form odd-numbered planes and even-numbered planes; The second expansion module is used to expand the odd bit planes and the even bit planes into an odd bit plane vector group b1 and an even bit plane vector group b2 respectively.

[0012] In a possible implementation, the diffusion unit includes: The first calculation module is used to calculate the sum of the elements of the low-order face group vector A2 ; The first circular shift module is used to circularly shift the high-order face group vector A1 to the right bits, and we get vector A 11 ; The first XOR operation module is used to operate vector A 11 , perform an XOR operation on the low-order face group vector A2 and the odd-order face group vector b1 to obtain a diffusion sequence B1 of the high-order face group vector A1; The second calculation module is used to calculate the sum of the elements of vector B1 ; The second circular shift module is used to circularly shift the low-order face group vector A2 to the right Get vector A 22 ; The second XOR operation module is used to operate vector A 22 , vector B1 and the even-bit plane vector group b2 are XORed to obtain the diffusion sequence B2 of the low-bit plane group vector A2.

[0013] According to one aspect of the present disclosure, there is provided a device, comprising: Processor and memory; The memory is used to store a computer program, and the processor calls the computer program stored in the memory to execute any one of the above-mentioned image chaotic tent mapping encryption methods.

[0014] According to one aspect of the present disclosure, a computer-readable storage medium is provided, in which a computer program is stored. When the computer program is executed by a processor, the processor is enabled to execute any one of the above-mentioned image chaotic tent mapping encryption methods.

[0015] The present disclosure has the following beneficial effects: the present disclosure converts an ordinary image into two binary bit planes of the same size, and adopts the method of expanding the binary bit planes into vectors for operation, thereby eliminating the correlation between adjacent pixels; by designing a diffusion strategy, the two sequences are mutually diffused, and then, by controlling the tent mapping, a chaotic sequence with good distribution and randomness is generated; the encryption scheme proposed in the present disclosure only requires one round of encryption, and has good encryption performance. The present disclosure can be widely used in the field of image transmission encryption communication. By exchanging the binary elements in the two sequences, the position in one bit plane can be exchanged to any other bit plane. The simulation results and performance analysis show that the image encryption algorithm of the present disclosure is safe and reliable.

[0016] The details of one or more embodiments of the present application are presented in the following drawings and descriptions. Other features and advantages of the present application will become apparent from the accompanying drawings. It should be understood that the above general description and the detailed descriptions below are only exemplary and explanatory and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0018] Figure 1 is a flow chart of an image chaos tent mapping encryption method of the present exemplary embodiment; Figure 2 is a flowchart of the encryption algorithm of this exemplary embodiment; Figure 3 Schematic diagram of a plaintext image and an encrypted image and diagonal pixel distribution thereof according to the exemplary embodiment; Figure 4 is a block diagram of an image chaos tent mapping encryption system of the present exemplary embodiment; Figure 5 It is a schematic structural diagram of a device of this exemplary embodiment. DETAILED DESCRIPTION

[0019] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as being limited to the examples set forth herein; on the contrary, these embodiments are provided so that the present disclosure will be more comprehensive and complete, and the concepts of the example embodiments are fully conveyed to those skilled in the art. The described features, structures, or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or other methods, components, devices, steps, etc. may be adopted. In other cases, known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0020] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware units or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0021] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the steps. For example, some steps may be decomposed, while some steps may be combined or partially combined, so the actual execution order may change according to the actual situation.

[0022] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0023] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or sub-modules is not necessarily limited to those steps or sub-modules explicitly listed, but may include other steps or sub-modules not explicitly listed or inherent to these processes, methods, products, or apparatuses.

[0024] Unlike traditional encryption algorithm technology, the chaotic system itself has "periodicity", "ergodicity" and "pseudo-randomness", and has high sensitivity to the set initial conditions and control parameters, so it is very suitable for image encryption. Many researchers use combination permutations and diffusion strategies to reduce the correlation between image components, thereby improving encryption performance. For bit-level permutations, the chaotic system can change the position and value of pixels at the same time. On this basis, the present disclosure proposes a bit-level image encryption algorithm.

[0025] Figure 1 is a flow chart of an image chaos tent mapping encryption method of this exemplary embodiment, such as Figure 1 As shown, an exemplary embodiment of the present disclosure provides an image chaotic tent mapping encryption method, comprising: Decomposing the plaintext image to be encrypted to obtain a high-order face group vector A1 and a low-order face group vector A2; Performing vector conversion processing on the high-order surface group vector A1 and the low-order surface group vector A2 to obtain an odd-numbered surface vector group b1 and an even-numbered surface vector group b2; Performing cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-numbered plane vector group b1 and the even-numbered plane vector group b2 to form a diffusion sequence B1 and a diffusion sequence B2; Perform n rounds of obfuscation processing on the diffusion sequence B1 and the diffusion sequence B2 to obtain the sequence C1 and the sequence C2; The sequence C1 and the sequence C2 are combined by bit plane operation to obtain an encrypted image.

[0026] It is worth noting that the plaintext image to be encrypted in this embodiment is an image in the civil aviation intelligent travel scenario. In image processing, information security and encryption technology, the plaintext image is an image that has not undergone any encryption processing and remains in the original data form before encryption or transmission.

[0027] like Figure 2 As shown, the chaotic tent mapping encryption method for images in the civil aviation intelligent travel scenario provided by this embodiment includes the following steps: Step 1, preparation stage: Decompose the plaintext image in the binary plane into the most significant bits (MSBs) and the least significant bits (LSBs), and then expand the two bit plane groups into vectors A1 and A2 respectively; Use key Tent-map is performed on vectors A1 and A2 respectively, and the number of iterations is Get the sequence Then, the elements of sequence X are rounded to get integer sequence X1, and the range of elements of sequence X1 is specified to be 0~255, where M*N represents the image size. It is worth noting that the key middle , They are the initial values ​​corresponding to the chaotic Tent_map mapping and its control parameters; the number of iterations middle Represents setting the initial iteration number of Tent_map to prevent direct Start iterating to improve encryption security, and only need a sequence of M*N length in the future.

[0028] Use the reshape function (a function used to convert a one-dimensional vector into a two-dimensional pixel matrix) to convert X1 to Type Matrix After that, Type Matrix Decompose the binary bit plane into odd bit plane and even bit plane, and expand them into vector groups b1 and b2 respectively.

[0029] Step 2, diffusion stage: (1) Calculate the sum of the elements of A2 ; (2) Circularly shift A1 right Get an A 11 ; (3) Perform XOR operation: , thus obtaining the sequence B1 after the diffusion of the A1 sequence (A1 vector).

[0030] (4) Calculate the sum of the elements of B1 ; (5) Circularly shift A2 right Get an A 22 ; (6) Perform XOR operation: , thus obtaining the sequence B2 after the diffusion of the A2 sequence (A2 vector).

[0031] Step 3, obfuscation phase: beg ; Use key The y0 in Processing (where L yes A 1 and A The size of 2, L yes ), get the new key ; It is worth noting that the key middle, , They are the initial values ​​corresponding to the chaotic Tent_map mapping and its control parameters respectively.

[0032] Use new key Perform N0+2L Temt-map processing to obtain the sequence ; Split the sequence S into and ; Then we perform element-wise rounding to get and .

[0033] Use the obtained obfuscated sequence to obfuscate again ; , the same applies to Z sequence; ; Finally, the obfuscated C1 and C2 sequences are obtained. It is worth noting that the Y and Z sequences generated here are used to confuse the B1 and B2 sequences in the second diffusion process. The specific obfuscation method is to set the loop variable i to [0, L-1], and then traverse the B1 and B2 sequences respectively. The traversal process is: temp_1, B1[i], B1[Y[i]]= B1[i], B1[Y[i]], temp_1;temp_2, B2[i], B2[Z[i]]= B2[i], B2[Z[i]], temp_2; This process uses temp_1 and temp_2 as zero-time variables to store the values ​​of B1[i] and B2[i], and finally makes the values ​​of B1[i] and B1[Y[i]] and B2[i] and B2[Z[i]] exchanged to achieve the purpose of obfuscation.

[0034] The two keys used in the experimental results of this embodiment are represented and The two control parameters in and The average value is 1.9.

[0035] Step 4: Generate encrypted image: Perform bit-plane combination operation on C1 and C2 sequences and merge them into an encrypted image.

[0036] This embodiment provides an image chaos tent mapping encryption scheme for civil aviation intelligent travel scenarios, which can utilize the high sensitivity of chaos mapping to initial conditions, system parameter values ​​and simple structures to effectively realize digital image data information encryption and provide good support for passenger personal privacy protection.

[0037] Specifically, the plaintext image to be encrypted is decomposed to obtain the high-order face group vector A1 and the low-order face group vector A2, including: Decomposing the plaintext image to be encrypted into a high-order face group and a low-order face group; The high-order face group and the low-order face group are expanded respectively to obtain the high-order face group vector A1 and the low-order face group vector A2.

[0038] Specifically, decomposing the plaintext image to form a high-order face group and a low-order face group includes: The plaintext image is divided into 8 binary bit planes using the binary bit plane decomposition method to form an 8-bit binary matrix a1~a8; The eight-bit binary matrices a1~a8 are divided into two groups, where a1~a4 are the low-order surface group and a5~a8 are the high-order surface group.

[0039] Specifically, the high-order plane group vector A1 and the low-order plane group vector A2 are subjected to vector conversion processing to obtain an odd-numbered plane vector group b1 and an even-numbered plane vector group b2, including: Using Keys Perform tent-map mapping on the high-order face group vector A1 and the low-order face group vector A2 respectively, and iterate the target number of times to obtain the sequence , , represents the elements in the sequence X, Indicates the size of the image; Round the elements of sequence X to obtain integer sequence X1; Convert the integer sequence X1 to Type Matrix ; Will Type Matrix Decompose to form odd-numbered planes and even-numbered planes; The odd bit planes and the even bit planes are expanded into an odd bit plane vector group b1 and an even bit plane vector group b2 respectively.

[0040] Specifically, performing cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-numbered plane vector group b1, and the even-numbered plane vector group b2 to form the diffusion sequence B1 and the diffusion sequence B2 includes: Calculate the sum of the elements of the low-order face group vector A2 ; Circularly shift the high-order face group vector A1 to the right bits, and we get vector A 11 ; Vector A 11, perform an XOR operation on the low-order face group vector A2 and the odd-order face group vector b1 to obtain a diffusion sequence B1 of the high-order face group vector A1; Calculate the sum of the elements of vector B1 ; Circularly shift right the low-order face group vector A2 Get vector A 22 ; Vector A 22 , vector B1 and the even-bit plane vector group b2 are XORed to obtain the diffusion sequence B2 of the low-bit plane group vector A2.

[0041] Specifically, decomposing the plaintext image to form a high-order face group and a low-order face group includes: The plaintext image is divided into 8 binary bit planes using the binary bit plane decomposition method to form an 8-bit binary matrix a1~a8; The eight-bit binary matrices a1~a8 are divided into two groups, where a1~a4 are the low-order surface group and a5~a8 are the high-order surface group.

[0042] Specifically, the image chaotic tent mapping encryption method of this embodiment includes a preparation stage, a diffusion stage, and an encrypted image merging stage. The specific steps of each stage are as follows: Preparation stage: 1) Binary face decomposition: In the field of image processing, it has been defined that each pixel value represents its color transparency, ranging from 0 to 255. Specifically, in a grayscale image, 0 represents the darkest pixel, and 255 represents the brightest pixel. This embodiment changes the decimal pixel value into an 8-bit binary pixel. After the data conversion process, 8 binary images are formed, whose pixel values ​​are composed of only 0 and 1.

[0043] (1) The plaintext image is decomposed by using the binary bitplane decomposition (BBD) method. The BBD method can divide a grayscale image into 8 binary bit planes. i Bits are used to form the i Decompose into eight-bit binary matrices (a1~a8), and then divide them into two groups, where a1~a4 is the low-order plane group and a5~a8 is the high-order plane group. Expand the two groups to obtain the high-order plane group vector A1 (MSBS) and the low-order plane group A2 vector (LSBS).

[0044] 2) Encryption processing: Assume the image size is Setting initial parameters and initial value x0 to iterate the mapping process times and discard the previous N 0 value to avoid harmful effects. Chaotic sequences have elements, Using formula (2) Convert to a sequence of integers .

[0045] (2) The range of elements in is 0 to 255. Using BBD Decompose into eight bit planes. In fact, there are eight binary sequences. Then, the sequences are flexibly divided into two groups. As an example, four odd bit planes are selected as one group, and four even bit planes are selected as the other group. By transforming these two groups of keys into binary sequences b 1 and b 2, get the binary key stream sequence. The elements of the bit plane are arranged from left to right and from high bit plane to low bit plane to form b 1 and b 2.

[0046] Diffusion stage: In the diffusion stage, chaos, cyclic shift and XOR operations are used to change the bit values ​​in A1 and A2 to generate B1 and B2.

[0047] Step 1: Calculate according to formula (3) A The sum of the elements in 2.

[0048] (3) in, L yes A 1 and A The size of 2, L yes .

[0049] Step 2: Use circular shift operation to obtain A 11 .here, A 11 yes A 1 Matrix circular shift right sum 1 bit.

[0050] Step 3: According to formula (4), by using A 11 The last element in A 2 and b 1 to encrypt the first element A 11The first element in .

[0051] (4) Step 4: Setup i＝2 , using formula (5) through formal element encryption A 11 The i elements, A 2 and b 1 of 1 i elements.

[0052] (5) Step 5: Setup i=i+1 , and return to step 4 until i achieve L . Use the same encryption method A 2.

[0053] Step 6: Calculate according to formula (6) B The sum of the elements in 1.

[0054] (6) Step 7: Use circular shift operation to obtain A 22 . A 22 yes A 2 Matrix circular shift to the right Bit.

[0055] Step 8: According to formula (7), by using A 22 The last element in B 1 and b 2 to encrypt the first element A 22 The first element in .

[0056] (7) Step 9: Setup , using formula (8) by A 22 The formal elements in B 1 and b 2 of 2 i Elements to encrypt A 22 Middle i elements.

[0057] (8) Step 10: Settings , and return to step 9 until i Reach L.

[0058] Encrypted image merging stage: In this stage, the obtained new B1 and B2 sequences are subjected to n rounds of confusion to obtain sequences C1 and C2. After obtaining the C1 and C2 sequences, they are converted into an image of size M*N after a bit-merging operation, and the obtained image is the encrypted image.

[0059] Key space analysis of this embodiment: Key space refers to the sum of all different keys that can be used in the process of encryption algorithm. A secure encryption algorithm should have a large enough key space to resist brute force attacks. When evaluating the security of an encryption algorithm, the key space is usually larger than 2. 100 In the algorithm proposed in this embodiment, the key selection includes the key used when obtaining the random image. key 1 (x0,u1) And the key required to obtain the obfuscation sequence during the obfuscation phase key 2 (y0,u2) The initial value and control parameters of the encryption round n and the number of iterations N 0. The calculation accuracy for this embodiment is 10 -14 For the initial value of the key space H x0 = H y0 = 10 14 , control parameters H u1 = H u2 = 10 14 , therefore, the total key space H = n·N0·H x0 ·H y0 ·H u1 ·H u2 = 10 48 ·n·N0≈ 2 159 ·n·N0. Even if the number of encryption rounds n = 1 And the number of chaos iterations N 0 = 1 When the total key space of the proposed scheme is 2 159 Sufficient to achieve a safety index value greater than 2 100 ,It is obvious that the algorithm proposed in this embodiment is sufficient to resist brute force attacks.

[0060] Correlation analysis: The correlation of an image mainly reflects the degree of correlation between pixels in the image. In the original image, adjacent pixels have extremely high correlation in the horizontal, vertical and diagonal directions. Therefore, the correlation between adjacent pixels in the encrypted image should be as low as possible to enable it to resist statistical attacks. In order to be able to intuitively compare the correlation difference between the plaintext image and the encrypted image, this embodiment randomly selects 1000 pairs of pixels in adjacent directions for the plaintext image and the encrypted image for comparison experiments. This experiment compares the diagonal pixels of the plaintext image with the diagonal pixels of the encrypted image. The results are as follows: Figure 3 shown.

[0061] From the experimental results, it can be concluded that the pixels of the plaintext image are highly concentrated, indicating that they are highly correlated, but the pixels of the encrypted ciphertext image are evenly distributed, indicating that the encrypted image has very low correlation. Pixel correlation is calculated using formulas (10)-(13): r xy = cov(x,y) / (10) E(x) = · (11) D(x) = · (12) cov(x,y) = · (13) In formulas (10) and (11), r xy represents the mutual correlation coefficient of x and y, E(x) and D(x) represent the mean and variance of x, E(y) and D(y) represent the mean and variance of y, cov(x, y) represents the cross-covariance of x and y, and S represents the size of the image for which the correlation is to be calculated.

[0062] The correlation coefficients between plaintext images and encrypted images are shown in Table 1.

[0063] Table 1. Correlation between adjacent pixels of plaintext image and ciphertext image

[0064] Between two pixels, a correlation coefficient of 1 indicates positive correlation, a correlation coefficient of -1 indicates negative correlation, and a correlation coefficient of 0 indicates no correlation. The experimental results show that the pixel values ​​of the plaintext image in each direction are around 0.9, indicating that the pixels in each direction of the plaintext image have a high correlation, while the absolute value of the correlation coefficient of the ciphertext image in each direction is basically close to 0.01, indicating that the pixels in each direction of the ciphertext image show very weak correlation. This comparative experiment shows that the proposed encryption algorithm has good obfuscation and diffusion characteristics and can resist pixel statistical attacks.

[0065] In summary, the security of data transmission over the network is very important, especially in the transportation industry. Therefore, encryption is a challenging and important task in network security. In recent years, chaos-based image encryption algorithms have been widely studied at the pixel level, but there are few studies on encryption algorithms at the bit level. The present invention proposes an encryption scheme of chaotic tent mapping. First, the ordinary image is converted into two binary bit planes of the same size, and the binary bit planes are expanded into vectors for operation, which eliminates the correlation between adjacent pixels. The two sequences are mutually diffused by designing a diffusion strategy. Then, a chaotic sequence with good distribution and randomness is generated by controlling the tent mapping. The encryption scheme only requires one round of encryption and has good encryption performance. Simulation results and performance analysis show that the algorithm is a safe and reliable image encryption algorithm. The present invention can be widely used in the field of image transmission encryption communication. The binary elements in the two sequences are exchanged, which can replace the position in one bit plane to any other bit plane. The algorithm only requires one round of encryption and has good encryption performance. Simulation results and performance analysis show that the algorithm is a safe and reliable image encryption algorithm. The present invention can be widely used in the field of image transmission encryption communication. The binary elements in the two sequences are exchanged, which can replace the position in one bit plane to any other bit plane. The algorithm only requires one round of encryption and has good encryption performance. Simulation results and performance analysis show that the algorithm is a safe and reliable image encryption algorithm.

[0066] Figure 4 is a block diagram of an image chaos tent mapping encryption system of the present exemplary embodiment, such as Figure 4 As shown, an exemplary embodiment of the present disclosure provides an image chaos tent mapping encryption system, comprising: A decomposition unit 10 is used to decompose the plaintext image to be encrypted to obtain a high-order face group vector A1 and a low-order face group vector A2; A conversion unit 20, configured to perform vector conversion processing on the high-order surface group vector A1 and the low-order surface group vector A2 to obtain an odd-order surface vector group b1 and an even-order surface vector group b2; A diffusion unit 30, configured to perform cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-numbered plane vector group b1 and the even-numbered plane vector group b2 to form a diffusion sequence B1 and a diffusion sequence B2; The obfuscation unit 40 is used to perform n rounds of obfuscation processing on the diffusion sequence B1 and the diffusion sequence B2 to obtain the sequence C1 and the sequence C2; The bit plane combining unit 50 is used to perform a bit plane combining operation on the sequence C1 and the sequence C2 to obtain an encrypted image.

[0067] Specifically, the decomposition unit includes: A first decomposition module is used to decompose the plaintext image to be encrypted to form a high-order surface group and a low-order surface group; The first expansion module is used to expand the high-order surface group and the low-order surface group respectively to obtain the high-order surface group vector A1 and the low-order surface group vector A2.

[0068] Specifically, the conversion unit includes: A mapping module is used to use the key to perform tent-map mapping on the high-order face group vector A1 and the low-order face group vector A2 respectively, and iterate the target number of times to obtain the sequence , , represents the elements in the sequence X, Indicates the size of the image; The rounding module is used to round the elements of the sequence X to obtain an integer sequence X1; Transformation module, used to transform the integer sequence X1 into Type Matrix ; The second decomposition module is used to Type Matrix Decompose to form odd-numbered planes and even-numbered planes; The second expansion module is used to expand the odd bit planes and the even bit planes into an odd bit plane vector group b1 and an even bit plane vector group b2 respectively.

[0069] Specifically, the diffusion unit includes: The first calculation module is used to calculate the sum of the elements of the low-order face group vector A2 ; The first circular shift module is used to circularly shift the high-order face group vector A1 to the right bits, and we get vector A 11 ; The first XOR operation module is used to operate vector A 11 , perform an XOR operation on the low-order face group vector A2 and the odd-order face group vector b1 to obtain a diffusion sequence B1 of the high-order face group vector A1; The second calculation module is used to calculate the sum of the elements of vector B1 ; The second circular shift module is used to circularly shift the low-order face group vector A2 to the right Get vector A 22 ; The second XOR operation module is used to operate vector A 22 , vector B1 and the even-bit plane vector group b2 are XORed to obtain the diffusion sequence B2 of the low-bit plane group vector A2.

[0070] Figure 5 Schematic diagram of the structure of a device of this exemplary embodiment. Figure 5As shown, corresponding to the image chaotic tent mapping encryption method provided above, the present disclosure also provides a device. Since the embodiment of the device is similar to the above method embodiment, the description is relatively simple. For the relevant parts, please refer to the description of the above method embodiment part. The device described below is only schematic. The device may include: a processor (processor) 1, a memory (memory) 2 and a communication bus (i.e., the above device bus) and a search engine, wherein the processor 1 and the memory 2 complete mutual communication through the communication bus and communicate with the outside through the communication interface. The processor 1 can call the logic instructions in the memory 2 to execute the image chaotic tent mapping encryption method.

[0071] In addition, the logic instructions in the above-mentioned memory 2 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present disclosure is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present disclosure. The aforementioned storage medium includes: a storage chip, a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and other media that can store program codes.

[0072] On the other hand, the embodiment of the present disclosure further provides a processor-readable storage medium, on which a computer program 3 is stored. When the computer program 3 is executed by the processor 1, the image chaotic tent mapping encryption method provided in the above embodiments is implemented.

[0073] The processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor 1, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NANDFLASH), solid-state drive (SSD)), etc.

[0074] The above are only preferred implementations of the present disclosure, and the protection scope of the present disclosure is not limited to the above embodiments. All technical solutions under the concept of the present disclosure belong to the protection scope of the present disclosure. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present disclosure should be regarded as the protection scope of the present disclosure.

Claims

1. An image chaos tent mapping encryption method, characterized in that: include: Decomposing the plaintext image to be encrypted to obtain a high-order face group vector A1 and a low-order face group vector A2; Performing vector conversion processing on the high-order surface group vector A1 and the low-order surface group vector A2 to obtain an odd-numbered surface vector group b1 and an even-numbered surface vector group b2; Performing cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-numbered plane vector group b1 and the even-numbered plane vector group b2 to form a diffusion sequence B1 and a diffusion sequence B2; Perform n rounds of obfuscation processing on the diffusion sequence B1 and the diffusion sequence B2 to obtain the sequence C1 and the sequence C2; The sequence C1 and the sequence C2 are combined by bit plane operation to obtain an encrypted image.

2. The image chaotic tent mapping encryption method according to claim 1, characterized in that: The plaintext image to be encrypted is decomposed to obtain the high-order face group vector A1 and the low-order face group vector A2, including: Decomposing the plaintext image to be encrypted into a high-order face group and a low-order face group; The high-order face group and the low-order face group are expanded respectively to obtain the high-order face group vector A1 and the low-order face group vector A2.

3. The image chaotic tent mapping encryption method according to claim 1, characterized in that: Performing vector conversion processing on the high-order plane group vector A1 and the low-order plane group vector A2 to obtain an odd-numbered plane vector group b1 and an even-numbered plane vector group b2 includes: Use the key to perform tent-map mapping on the high-order face group vector A1 and the low-order face group vector A2 respectively, and iterate the target number of times to obtain the sequence , , represents the elements in the sequence X, Indicates the size of the image; Round the elements of sequence X to obtain integer sequence X1; Convert the integer sequence X1 to Type Matrix ; Will Type Matrix Decompose to form odd-numbered planes and even-numbered planes; The odd bit planes and the even bit planes are expanded into an odd bit plane vector group b1 and an even bit plane vector group b2 respectively.

4. The image chaotic tent mapping encryption method according to claim 1, characterized in that: Performing cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-numbered plane vector group b1, and the even-numbered plane vector group b2 to form diffusion sequences B1 and B2 includes: Calculate the sum of the elements of the low-order face group vector A2 ; Circularly shift the high-order face group vector A1 to the right bits, and we get vector A 11 ; Vector A 11 , perform an XOR operation on the low-order face group vector A2 and the odd-order face group vector b1 to obtain a diffusion sequence B1 of the high-order face group vector A1; Calculate the sum of the elements of vector B1 ; Circularly shift right the low-order face group vector A2 Get vector A 22 ; Vector A 22 , vector B1 and the even-numbered bit plane vector group b2 are XORed to obtain the diffusion sequence B2 of the low-numbered bit plane group vector A2.

5. An image chaos tent mapping encryption system, characterized in that: include: A decomposition unit, used for decomposing the plaintext image to be encrypted to obtain a high-order face group vector A1 and a low-order face group vector A2; A conversion unit, used for performing vector conversion processing on the high-order surface group vector A1 and the low-order surface group vector A2 to obtain an odd-numbered surface vector group b1 and an even-numbered surface vector group b2; A diffusion unit, configured to perform cyclic shift and XOR operations based on the high-order plane group vector A1, the low-order plane group vector A2, the odd-numbered plane vector group b1, and the even-numbered plane vector group b2 to form a diffusion sequence B1 and a diffusion sequence B2; A confusion unit, used for performing n rounds of confusion processing on the diffusion sequence B1 and the diffusion sequence B2 to obtain the sequence C1 and the sequence C2; The bit plane combination unit is used to perform a bit plane operation on the sequence C1 and the sequence C2 to obtain an encrypted image.

6. The image chaos tent mapping encryption system according to claim 5, characterized in that: Decomposition unit, including: A first decomposition module is used to decompose the plaintext image to be encrypted to form a high-order surface group and a low-order surface group; The first expansion module is used to expand the high-order surface group and the low-order surface group respectively to obtain the high-order surface group vector A1 and the low-order surface group vector A2.

7. The image chaos tent mapping encryption system according to claim 5, characterized in that: The conversion unit includes: A mapping module is used to use the key to perform tent-map mapping on the high-order face group vector A1 and the low-order face group vector A2 respectively, and iterate the target number of times to obtain the sequence , , represents the elements in the sequence X, Indicates the size of the image; The rounding module is used to round the elements of the sequence X to obtain an integer sequence X1; Transformation module, used to transform the integer sequence X1 into Type Matrix ; The second decomposition module is used to Type Matrix Decompose to form odd-numbered planes and even-numbered planes; The second expansion module is used to expand the odd bit planes and the even bit planes into an odd bit plane vector group b1 and an even bit plane vector group b2 respectively.

8. The image chaos tent mapping encryption system according to claim 5, characterized in that: The diffusion unit includes: The first calculation module is used to calculate the sum of the elements of the low-order face group vector A2 ; The first circular shift module is used to circularly shift the high-order face group vector A1 to the right bits, and we get vector A 11 ; The first XOR operation module is used to operate vector A 11 , perform an XOR operation on the low-order face group vector A2 and the odd-order face group vector b1 to obtain a diffusion sequence B1 of the high-order face group vector A1; The second calculation module is used to calculate the sum of the elements of vector B1 ; The second circular shift module is used to circularly shift the low-order face group vector A2 to the right Get vector A 22 ; The second XOR operation module is used to operate vector A 22 , vector B1 and the even-numbered bit plane vector group b2 are XORed to obtain the diffusion sequence B2 of the low-numbered bit plane group vector A2.

9. A device, characterized in that: include: Processor and memory; The memory is used to store a computer program, and the processor calls the computer program stored in the memory to execute the image chaotic tent mapping encryption method according to any one of claims 1 to 4.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor is enabled to execute the image chaotic tent mapping encryption method according to any one of claims 1 to 4.

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