A chaotic block encryption method, system and medium based on random selection of models

Abstract

The present invention discloses a chaotic block encryption method, system and medium based on random selection of a model, which belongs to the field of information security technology and is used to solve the technical problems that the existing chaotic encryption algorithm is easily cracked and maliciously attacked when used alone, and relies on the internal characteristics of nonlinear functions, does not expand the secret key space, and has limited improvement on the security of the secret key. The method includes: based on a preset chaotic system, constructing a chaotic system model library; the chaotic system model library contains several chaotic subsystems; based on binary coding, generating a secret key initial field for the original image; according to the secret key initial field, selecting a corresponding target chaotic subsystem in the chaotic system model library; encrypting the original image through the target chaotic subsystem to obtain an encrypted image. The present invention designs a row-level image chaotic encryption algorithm to improve the image encryption speed. It also increases the secret key length, expands the secret key space, and increases the security of the secret key.

Description

Technical Field

[0001] The present invention relates to the field of information security technology, and in particular to a chaotic block encryption method, system and medium based on random selection of models. Background Art

[0002] In recent years, more and more image data has been transmitted and stored in the network. In all walks of life, the privacy of information has become a crucial issue. Traditional encryption algorithms, such as DES, AES, RSA and other algorithms, are only applicable to text structured data and are not suitable for encrypting image data. In order to solve the problem of image encryption, chaotic encryption algorithms have been proposed. The main advantages of chaotic encryption algorithms are that the secret key space is extended from integer space to real number space, and it is extremely sensitive to the initial value of the system. Therefore, chaotic encryption algorithms generally set the initial value of the system as the secret key.

[0003] The current chaos encryption algorithms have weaknesses such as weak chaotic mapping, weak resistance to certain types of attacks, insufficient sensitivity to plaintext and secret keys, and small secret key space. Although various chaos encryption algorithms have emerged in an endless stream and have certain encryption effects, these encryption algorithms are often used alone and are easily cracked and maliciously attacked. Moreover, these algorithms rely heavily on the internal characteristics of nonlinear functions and do not expand the secret key space, which has limited improvement on the security of secret keys. Summary of the invention

[0004] The embodiments of the present invention provide a chaotic block encryption method, system and medium based on random selection of a model, which are used to solve the following technical problems: the existing chaotic encryption algorithm is easy to be cracked and maliciously attacked when used alone, and relies on the internal characteristics of nonlinear functions, and does not expand the key space, and the improvement of the key security is relatively limited.

[0005] The embodiment of the present invention adopts the following technical solutions:

[0006] On the one hand, an embodiment of the present invention provides a chaotic block encryption method based on random selection of models, the method comprising: constructing a chaotic system model library based on a preset chaotic system; the chaotic system model library includes a plurality of chaotic subsystems;

[0007] Generate the initial field of the secret key for the original image based on binary encoding;

[0008] According to the initial field of the secret key, selecting a corresponding target chaotic subsystem in the chaotic system model library;

[0009] The original image is encrypted by the target chaotic subsystem to obtain an encrypted image.

[0010] In a feasible implementation, based on a preset chaotic system, a chaotic system model library is constructed, specifically including:

[0011] Obtain a state space expression of a preset chaotic system; wherein the preset chaotic system at least includes Lorenz Chaotic systems, Chen Chaotic systems and Rossler Chaotic systems;

[0012] Based on different state channels in each preset chaotic system, each preset chaotic system is divided into a plurality of different chaotic subsystems, and corresponding subsystem expressions are obtained respectively;

[0013] All the obtained chaotic subsystems are stored in a preset manner to form the chaotic system model library.

[0014] In a feasible implementation, the preset storage form includes at least a matrix storage form and a row-level storage form; the matrix storage form refers to storing all chaotic subsystems in a matrix arrangement; the row-level storage form refers to arranging all chaotic subsystems into a whole row in a preset order for storage.

[0015] In a feasible implementation, based on binary encoding, a key initial field is generated for the original image, specifically including:

[0016] Based on the storage form of the chaotic subsystem, a corresponding binary code is randomly generated for each row of image data in the original image as the key initial field of this row of image data; wherein the length of the binary code is the same as the total number of chaotic subsystems in the chaotic system model library.

[0017] In a feasible implementation manner, when the storage form of the chaotic subsystem is a matrix storage form, a corresponding binary coding matrix is ​​generated according to the matrix formed by the chaotic subsystem; wherein the dimension of the binary coding matrix is ​​the same as the matrix dimension of the chaotic subsystem;

[0018] According to the number of matrix rows of the chaotic subsystem, the original image is divided into rows;

[0019] Each row of binary code in the binary code matrix is ​​determined as a key initial field of the corresponding row of image data.

[0020] In a feasible implementation, when the storage form of the chaotic subsystem is a row-level storage form, a corresponding binary code is generated for each row of image data according to the order of the chaotic subsystem to obtain a key initial field for each row of image data.

[0021] In a feasible implementation, according to the initial field of the secret key, selecting a corresponding target chaotic subsystem in the chaotic system model library specifically includes:

[0022] Traversing all characters in the initial field of the secret key, if the character value read is 1, then according to the order of the characters in the initial field of the secret key, obtaining a chaotic subsystem of a corresponding order in the chaotic system model library, and determining it as a target chaotic subsystem;

[0023] After the traversal is completed, all target chaotic subsystems are obtained and the corresponding subsystem expressions are extracted.

[0024] In a feasible implementation manner, encrypting the original image by the target chaotic subsystem to obtain an encrypted image specifically includes:

[0025] Generate the same number of random weights according to the number of target chaotic subsystems obtained;

[0026] Using the initial value of the system state of each target chaotic subsystem as an encryption key, encrypting the corresponding row data in the original image to obtain multiple initial ciphertexts corresponding to the row data;

[0027] By using the random weight, weighted calculation is performed on multiple initial ciphertexts of the row of data to obtain ciphertext data of the row of data;

[0028] After each row of data of the original image is encrypted, the encrypted image is obtained.

[0029] On the other hand, an embodiment of the present invention further provides a chaotic block encryption system based on random selection of a model, the system comprising:

[0030] A chaotic system model library is used to construct a chaotic system model library based on a preset chaotic system; the chaotic system model library includes a plurality of chaotic subsystems;

[0031] The encryption module is used to generate a secret key initial field for the original image based on binary coding; select a corresponding target chaotic subsystem in the chaotic system model library according to the secret key initial field; encrypt the original image through the target chaotic subsystem to obtain an encrypted image.

[0032] Finally, an embodiment of the present invention also provides a storage medium, which is a non-volatile computer-readable storage medium, and the non-volatile computer-readable storage medium stores at least one program, each of which includes instructions, and when the instructions are executed by a terminal, the terminal executes the chaotic block encryption method based on random selection of a model.

[0033] Compared with the prior art, the chaotic block encryption method, system and medium based on random selection of models provided by the embodiments of the present invention have the following beneficial effects:

[0034] The chaotic encryption algorithm based on random selection of models proposed in the present invention first constructs a chaotic system model library by injecting the original text into different state channels of different chaotic systems, and then in the process of encrypting the image, the image is first grouped at the row level, and then for each row of images, different chaotic subsystems are randomly extracted from the chaotic system model library to encrypt this row of data, and then a random weight matrix is ​​used for linear combination to obtain the encrypted data of each row of images. The present invention uses the properties of the image to design a row-level image chaotic encryption algorithm, which improves the encryption speed of the image. In addition, the present invention adds a random model binary code to the beginning field of the secret key as the initial field of the secret key, thereby increasing the length of the secret key, expanding the secret key space, and increasing the security of the secret key. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0036] Figure 1 A flow chart of a chaotic block encryption method based on random selection of models provided by an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of a chaotic system model library provided by an embodiment of the present invention;

[0038] Figure 3 An example diagram of an initial field of a secret key provided by an embodiment of the present invention;

[0039] Figure 4 An example diagram of an image encryption process of a chaotic block encryption module provided by an embodiment of the present invention;

[0040] Figure 5 An example diagram of an image encryption process of another chaotic block encryption module provided by an embodiment of the present invention;

[0041] Figure 6 A ciphertext parsing flow chart based on system inversion provided by an embodiment of the present invention;

[0042] Figure 7 A schematic diagram of the structure of a chaotic block encryption system based on random selection of models provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] The embodiment of the present invention provides a chaotic block encryption method based on random selection of models, such as Figure 1 As shown, the chaotic block encryption method based on random selection of a model specifically includes steps S101-S104:

[0045] S101. Based on a preset chaotic system, a chaotic system model library is constructed; the chaotic system model library includes a plurality of chaotic subsystems.

[0046] Specifically, firstly, a state space expression of a preset chaotic system is obtained; wherein the preset chaotic system at least includes Lorenz Chaotic systems, Chen Chaotic systems and Rossler Chaotic system.

[0047] Then, based on different state channels in each preset chaotic system, each preset chaotic system is divided into a plurality of different chaotic subsystems, and the corresponding subsystem expressions are obtained respectively. All the obtained chaotic subsystems are stored in a preset form to form a chaotic system model library.

[0048] As a feasible implementation method, the chaotic system model library provided by the present invention is mainly composed of Lorenz chaotic system, Chen chaotic system and Rossler chaotic system. Specifically, the Lorenz nonlinear system is a typical chaotic system, and its state space expression is as follows:

[0049] ;in, , , are different state expressions of the system, is the output of the system. , , When , the Lorenz system exhibits chaotic phenomena.

[0050] The state space expression of Chen chaotic system is as follows:

[0051] ;in, , , are different state expressions of the system, is the output of the system. , , When , the Chen system exhibits chaotic phenomena.

[0052] Finally, the state space expression of the Rossler chaotic system is as follows:

[0053] ;in, , , are different state expressions of the system, is the output of the system. , , , When , the Rossler system exhibits chaotic phenomena.

[0054] For each type of chaotic system mentioned above, since plaintext can be injected into different state channels, each type of chaotic system can be divided into three different chaotic subsystems, namely:

[0055] The Lorenz chaotic system is divided into three Lorenz subsystems , , :

[0056] : ;

[0057] : ;

[0058] : .

[0059] The Chen chaotic system is divided into three Chen chaotic subsystems , , :

[0060] : ;

[0061] : ;

[0062] : .

[0063] The Rossler chaotic system is divided into three Rossler chaotic subsystems , , :

[0064] : ;

[0065] : ;

[0066] : .

[0067] Furthermore, the preset storage form of the chaotic subsystem includes at least a matrix storage form and a row storage form. The matrix storage form refers to storing all chaotic subsystems in a matrix arrangement; the row storage form refers to arranging all chaotic subsystems in a preset order into a whole row for storage. Figure 2 A schematic diagram of a chaotic system model library provided by an embodiment of the present invention, Figure 2 The storage method shown is in matrix form. The above nine chaotic subsystems are stored as follows: Figure 2 The matrix arrangements shown constitute a chaotic system model library.

[0068] S102: Generate a secret key initial field for the original image based on binary encoding.

[0069] Specifically, the encryption module randomly generates a corresponding binary code for each row of image data in the original image based on the storage form of the chaotic subsystem, which serves as the initial field of the secret key for this row of image data; wherein the length of the binary code is the same as the total number of chaotic subsystems in the chaotic system model library.

[0070] As a feasible implementation, when the storage form of the chaotic subsystem is a matrix storage form, a corresponding binary coding matrix is ​​generated according to the matrix formed by the chaotic subsystem; wherein the dimension of the binary coding matrix is ​​the same as the matrix dimension of the chaotic subsystem.

[0071] Then, the original image is divided into rows according to the number of matrix rows of the chaotic subsystem; and each row of binary code in the binary coding matrix is ​​determined as the key initial field of the corresponding row of image data.

[0072] Furthermore, each chaotic subsystem in the chaotic system model library corresponds to two binary values, a value of 0 indicates that it is not selected, and a value of 1 indicates that it is selected. Based on the sequential arrangement of the chaotic subsystems in the chaotic system model library, the corresponding binary codes are randomly generated.

[0073] In one embodiment, when the subsystem storage form in the chaotic system model library is in matrix form, the randomly generated initial field of the secret key is also in matrix form of the same dimension. Figure 3 An example diagram of an initial field of a secret key provided by an embodiment of the present invention is shown in FIG. Figure 3 As shown, the randomly generated binary code is 101011100 and is arranged in a matrix form. Figure 4 An example diagram of an image encryption process of a chaotic block encryption module provided by an embodiment of the present invention is shown in FIG. Figure 4 As shown, since the matrix dimension of the chaotic subsystem is 3×3, the original image is divided into images of size 3×3, and then the first row of images is encrypted based on the first row code "101" of the initial field of the secret key, the second row of images is encrypted based on the second row code "011", and the third row of images is encrypted based on the third row code "100".

[0074] In another embodiment, Figure 5 Another example diagram of the image encryption process of the chaotic block encryption module provided by the embodiment of the present invention is shown in FIG. Figure 5 As shown in the figure, when the subsystems in the chaotic system model library are arranged in a row, the original image is divided into several rows of data, and a corresponding binary code is generated for each row of data as the initial field of the secret key of the current row of data. If the initial field of the secret key randomly generated for the first row of image data is 100010000, the Lorenz subsystem is selected. and Chen subsystem To encrypt the first row of images, random weights are introduced for linear combination to obtain the ciphertext image of the first row of images. This process is repeated until each row of images is encrypted.

[0075] Image data is generally in matrix form. The present invention first groups the original image at the row level and divides the image into several rows of data. Then, for each row of data, different chaotic subsystems are randomly selected from the chaotic system model library to encrypt each row of data respectively. Then, the encryption results of each chaotic subsystem are linearly combined using random weights to obtain the encrypted data of each row of image data, and then the encrypted image is obtained.

[0076] S103. According to the initial field of the secret key, a corresponding target chaotic subsystem is selected from the chaotic system model library.

[0077] Specifically, the encryption module traverses all characters in the initial field of the secret key. If the character value read is 1, the chaotic subsystem of the corresponding order is obtained in the chaotic system model library according to the order of the characters in the initial field of the secret key, and is determined as the target chaotic subsystem; after the traversal is completed, all target chaotic subsystems are obtained, and the corresponding subsystem expressions are extracted.

[0078] Furthermore, the encryption module uses the determined initial value of the system state of the target chaotic subsystem as the encryption key to encrypt each line of image data and obtain the initial ciphertext. Then, using binary coding, the selected chaotic subsystem is constructed as the initial field of the key, and the initial field is placed at the beginning of the encryption key and sent to the decryption module together.

[0079] S104, encrypting the original image through the target chaotic subsystem to obtain an encrypted image.

[0080] Specifically, according to the number of target chaotic subsystems obtained, the same number of random weights is generated. The initial value of the system state of each target chaotic subsystem is used as the encryption key to encrypt the corresponding row data in the original image to obtain multiple initial ciphertexts corresponding to the row data.

[0081] Furthermore, a weighted calculation is performed on multiple initial ciphertexts of the row of data by random weights to obtain the ciphertext data of the row of data. After each row of data of the original image is encrypted, an encrypted image is obtained.

[0082] In one embodiment, Figure 4 As shown, the first line of the secret key initial field is 101, which means the Lorenz subsystem is selected. and subsystems Encrypt the first row of images separately and introduce corresponding random weights and After introducing random weights, the ciphertext data of the first row of images is The second line of the key initial field 011 indicates that the Chen subsystem is selected. and subsystems The second row of the image is encrypted separately, and so on, until the encryption of the entire image is completed.

[0083] Furthermore, during decryption, the decryption module parses the received initial field of the secret key to determine the target chaotic subsystem used during encryption.

[0084] Specifically, after receiving the encrypted image and the secret key in the decryption stage, the secret key initial field in the secret key is obtained, and all characters in the secret key initial field are traversed.

[0085] Furthermore, according to the sequence value of the character value of 1, the chaotic subsystems of the corresponding sequence are determined in the chaotic system model library, and all target chaotic subsystems used in encrypting the encrypted image are obtained.

[0086] In one embodiment, after receiving the secret key, the decryption module can determine which chaotic subsystems the encryption module randomly selected for encryption based on the beginning field of the secret key. For example, when the beginning field of the secret key received by the decryption module is 100010000, the decryption module knows that the encryption module selected the Lorenz subsystem. and Chen subsystem To encrypt the original image.

[0087] Then the encrypted image is decrypted according to the target chaotic subsystem to obtain the original image.

[0088] Specifically, according to the total number of target chaotic subsystems used when encrypting the encrypted image n , determine the number of random weights to be solved n . Then randomly generate n -1 groups of auxiliary weight vectors; each group of auxiliary weight vectors contains n auxiliary weights. Finally, the random weights to be solved and the n-1 groups of auxiliary weight vectors are constructed into a weight matrix; the dimension of the weight matrix is n × n .

[0089] As a feasible implementation, after determining the n chaotic subsystems used by the encryption module, the remaining work is to determine the random weights in the secret key. When decrypting the ciphertext image, the decryption module sends a decryption request to the encryption module. The encryption module randomly generates n-1 sets of auxiliary weights and forms a n × n The non-singular weight matrix of .

[0090] In one embodiment, when decrypting the first row of images, since the key starts with 100010000, the ciphertext of the first row of images can be determined to be ,in, and are the two random weights required. Since two chaotic subsystems are selected, the encryption module generates a set of auxiliary weights . However, the weight matrix is ​​defined as: .

[0091] Furthermore, the corresponding row data of the original image is auxiliary encrypted by the auxiliary weight vector to obtain the corresponding auxiliary ciphertext. Then, based on the ciphertext data of the original image and the auxiliary ciphertext, a ciphertext vector is defined. According to the initial ciphertext output by each subsystem, an initial ciphertext vector is defined.

[0092] Furthermore, based on the ciphertext vector, the weight matrix and the initial ciphertext vector, a ciphertext linear equation system is constructed, and the unique solution of the decrypted linear equation system is obtained to obtain the inverse matrix of the weight matrix. Finally, the corresponding row data of the encrypted image is parsed by the inverse matrix. After all the row data are parsed, the original image is obtained.

[0093] As a feasible implementation method, based on the ciphertext vector, the weight matrix and the initial ciphertext vector, a ciphertext linear equation system is constructed, and a unique solution of the deciphertext linear equation system is obtained to obtain the inverse matrix of the weight matrix, which specifically includes:

[0094] when t ≥0, the ciphertext linear equation system is obtained ;in, C ( t ) is the ciphertext vector, Y ( t ) is the initial ciphertext vector, W is the weight matrix. Let the weight matrix W Rank rank ( W )= n , at this time the weight matrix is ​​a non-singular matrix, the ciphertext linear equations have a unique solution, and the inverse matrix of the weight matrix is ​​obtained by solving W -1 .

[0095] In one embodiment, Figure 5 As shown, in the encryption module, after the first row of the original image is encrypted by the auxiliary weight, the auxiliary ciphertext generated is defined as .

[0096] Then define the ciphertext vector as ,in, c ( t ) is the ciphertext data of the first row of image received by the decryption module, c 1 ( t ) is the auxiliary ciphertext sent by the encryption module. The initial ciphertext vector is defined as .

[0097] Therefore, when When , the linear equations of the ciphertext are: .

[0098] When the rank When the weight matrix W is a non-singular matrix. At this time, the unique solution of the above linear equations can be found at a certain time, that is, , find the inverse matrix of the weight matrix W .

[0099] Figure 6 A ciphertext parsing flow chart based on system inversion provided by an embodiment of the present invention is as follows: Figure 6 As shown, based on the element values ​​in the inverse matrix, the initial ciphertext can be parsed as:

[0100] ;

[0101] Then, any initial ciphertext parsed is derived. y L1 ( t ) and we get .

[0102] Therefore, the original text can be decrypted as: .

[0103] By using the characteristic that if the coefficient matrix of the linear equation system is not full rank, then the system solution will be infinite, and using random weights to linearly combine the ciphertexts of multiple chaotic subsystems, even if the attacker obtains the ciphertext, he will only get an infinite number of sets of weight values, and cannot find a unique solution or crack the original text. In order to ensure that the decryption module can successfully decrypt the image, the present invention introduces the idea of ​​auxiliary ciphertext, and the encryption module cooperates to randomly generate n-1 groups of auxiliary ciphertexts, which form a full-rank coefficient matrix with the unknown weights that need to be solved, so that the unique weight combination can be found, the original text can be parsed, and the security of image encryption is improved.

[0104] In addition, the embodiment of the present invention also provides a chaotic block encryption system based on random selection of models, such as Figure 7 As shown, the chaotic block encryption system 700 based on random selection of models specifically includes:

[0105] A chaotic system model library 710 is used to construct a chaotic system model library based on a preset chaotic system; the chaotic system model library includes a plurality of chaotic subsystems;

[0106] The encryption module 720 is used to generate a secret key initial field for the original image based on binary coding; select a corresponding target chaotic subsystem from the chaotic system model library according to the secret key initial field; encrypt the original image through the target chaotic subsystem to obtain an encrypted image.

[0107] As a feasible implementation, the system also includes a decryption module 730, which is used to parse the received initial field of the secret key during the decryption stage to determine the target chaotic subsystem used for encryption; decrypt the encrypted image according to the target chaotic subsystem to obtain the original image.

[0108] Each embodiment of the present invention is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, system, and non-volatile computer storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0109] The above describes specific embodiments of the present invention. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0110] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention should be included in the protection scope of the present invention.

Claims

1. A chaotic block encryption method based on random selection of models, characterized in that: The method comprises: Based on the preset chaotic system, a chaotic system model library is constructed; the chaotic system model library includes a plurality of chaotic subsystems; Based on binary encoding, generate the initial field of the secret key for the original image, including: Based on the storage form of the chaotic subsystem, for each row of image data in the original image, a corresponding binary code is randomly generated as the key initial field of this row of image data; wherein the length of the binary code is the same as the total number of chaotic subsystems in the chaotic system model library; In the case where the storage form of the chaotic subsystem is a matrix storage form, a corresponding binary coding matrix is ​​generated according to the matrix formed by the chaotic subsystem; wherein the dimension of the binary coding matrix is ​​the same as the matrix dimension of the chaotic subsystem; According to the number of matrix rows of the chaotic subsystem, the original image is divided into rows; and each row of binary code in the binary code matrix is ​​determined as a key initial field of the corresponding row of image data; In the case where the storage form of the chaotic subsystem is a row-level storage form, a corresponding binary code is generated for each row of image data according to the order of the chaotic subsystem to obtain a key initial field of each row of image data; According to the initial field of the secret key, selecting a corresponding target chaotic subsystem in the chaotic system model library; The original image is encrypted by the target chaotic subsystem to obtain an encrypted image.

2. The chaotic block encryption method based on random selection of models according to claim 1 is characterized in that: Based on the preset chaotic system, a chaotic system model library is constructed, including: Obtain a state space expression of a preset chaotic system; wherein the preset chaotic system at least includes Lorenz Chaotic systems, Chen Chaotic systems and Rossler Chaotic systems; Based on different state channels in each preset chaotic system, each preset chaotic system is divided into a plurality of different chaotic subsystems, and corresponding subsystem expressions are obtained respectively; All the obtained chaotic subsystems are stored in a preset manner to form the chaotic system model library.

3. The chaotic block encryption method based on random selection of models according to claim 2 is characterized in that: The preset storage form includes at least a matrix storage form and a row-level storage form; the matrix storage form refers to storing all chaotic subsystems in a matrix arrangement; the row-level storage form refers to arranging all chaotic subsystems into a whole row in a preset order for storage.

4. The chaotic block encryption method based on random selection of models according to claim 1 is characterized in that: According to the initial field of the secret key, a corresponding target chaotic subsystem is selected in the chaotic system model library, specifically including: Traversing all characters in the initial field of the secret key, if the character value read is 1, then according to the order of the characters in the initial field of the secret key, obtaining a chaotic subsystem of a corresponding order in the chaotic system model library, and determining it as a target chaotic subsystem; After the traversal is completed, all target chaotic subsystems are obtained and the corresponding subsystem expressions are extracted.

5. The chaotic block encryption method based on random selection of models according to claim 4 is characterized in that: Encrypting the original image by the target chaotic subsystem to obtain an encrypted image specifically includes: Generate the same number of random weights according to the number of target chaotic subsystems obtained; Using the initial value of the system state of each target chaotic subsystem as an encryption key, encrypting the corresponding row data in the original image to obtain multiple initial ciphertexts corresponding to the row data; By using the random weight, weighted calculation is performed on multiple initial ciphertexts of the row of data to obtain ciphertext data of the row of data; After each row of data of the original image is encrypted, the encrypted image is obtained.

6. A chaotic block encryption system based on random selection of a model, using a chaotic block encryption method based on random selection of a model as described in any one of claims 1 to 5, characterized in that: The system comprises: A chaotic system model library is used to construct a chaotic system model library based on a preset chaotic system; the chaotic system model library includes a plurality of chaotic subsystems; The encryption module is used to generate a secret key initial field for the original image based on binary coding; select a corresponding target chaotic subsystem in the chaotic system model library according to the secret key initial field; encrypt the original image through the target chaotic subsystem to obtain an encrypted image.

7. A storage medium, characterized in that: The storage medium is a non-volatile computer-readable storage medium, which stores at least one program, each of which includes instructions. When the instructions are executed by the terminal, the terminal executes a chaotic block encryption method based on random selection of a model according to any one of claims 1-5.

Images