Content resource encryption method and device and content resource recovery method and device based on Pailier cryptosystem

Abstract

The invention relates to a content resource encryption method and device and a content resource recovery method and device based on a Pailier cryptosystem. The method comprises the following steps of: firstly, calculating a reserved space for embedding additional information by utilizing a self-embedding strategy, and operating a subject term vector matrix of a service content resource by using a Pailer password system to construct a corresponding mirror image ciphertext group; and then, the metadata corresponding to the service content resource and the content service information are fused to form additional information, the additional information is encrypted by using a data hiding key, and the additional information is embedded into the reserved space through homomorphic multiplication, so that the encryption of the service content resource is completed, and the corresponding information is transmitted to the user according to the user permission. Therefore, the copyright protection purpose of the content resources is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of data encryption and recovery, and in particular to a content resource encryption method, recovery method and device. Background Art

[0002] AIGC stands for artificial intelligence generated content, which means that artificial intelligence automatically generates various content, such as text, images, audio, video, etc. by learning large amounts of data. It is a new content creation method after expert generated content (PGC, Professional Generated Content) and user generated content (UGC, User Generated Content).

[0003] Although AIGC can customize consumption content for users in real time according to user needs, realize personalized content services, and reconstruct the entire content industry, this personalized generation is selected and reorganized from a large number of content resources, which is prone to infringement, bringing negative impacts to relevant stakeholders, and further affecting the innovative development of the entire content industry.

[0004] The methods described in this section are not necessarily methods that have been previously conceived or employed. Unless otherwise indicated, it should not be assumed that any method described in this section is considered to be prior art simply because it is included in this section. Similarly, unless otherwise indicated, the issues mentioned in this section should not be considered to have been recognized in any prior art. Summary of the invention

[0005] The present invention aims at the technical problems existing in the prior art and provides a content resource encryption method, recovery method and device based on the Pailier cryptographic system.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] In a first aspect, the present invention provides a content resource encryption method based on the Pailier cryptographic system, comprising:

[0008] Extracting service content resources, metadata used to describe the service content resources, and service information corresponding to the service content resources from a content resource library;

[0009] Generate a corresponding theme matrix according to the service content resources, and generate corresponding additional information according to the metadata and service information;

[0010] The self-embedding strategy is used to create the reserved space required for embedding additional information in the subject matrix, and the Pailler cryptographic system is used to operate the subject matrix of the service content resource to construct the corresponding mirror ciphertext group;

[0011] The additional information is encrypted using the data hiding key Kw, and based on the mirror ciphertext group, the encrypted additional information is embedded into the reserved space through homomorphic multiplication to complete the hiding of the additional information in the service content resource.

[0012] Furthermore, the generating of a corresponding theme matrix according to the service content resources includes:

[0013] Performing text structure analysis on the service content resources to generate a set of ordered consumption content resource blocks;

[0014] Traverse all consumption content resource blocks, perform semantic analysis on each consumption content resource block, and generate corresponding topic word vectors;

[0015] A topic matrix with a capacity of L*R is constructed according to the topic word vector.

[0016] Furthermore, the self-embedding strategy is used to create a reserved space in the topic matrix required for embedding additional information, including:

[0017] Divide the topic matrix into I A and I A two non-overlapping parts, and further I A Divided into I C and I B , where I C The capacity is L C *R C , the rest is I B , L C , R C All are multiples of 2;

[0018] to I A Perform grouping, each group contains a reference topic and T main topics, and use the group selection key Kg to select some groups as target groups;

[0019] Extraction I A Reference topics and main topics for each group in I B The value of the least significant bit of each topic in generates the bit set b = {b A ,b B}, where b A = {b r ,b h}, b r , b h The least significant bits of the reference topic and the main topic are represented by b B Indicates I B The least significant bits of each topic in ;

[0020] The bit set b is embedded into IC using the additive prediction error expansion method, and I is retained. A The least significant bits of the reference subject and main subject of each group are embedded in the reserved space required as additional information.

[0021] Furthermore, the Pailler cryptographic system is used to operate the subject matrix of the service content resource to construct the corresponding mirror ciphertext group, including:

[0022] After creating the reserved space for the topic matrix, randomly select an integer Encrypt the subject matrix using the public key (N, g), where i ≤ L, j ≤ R, and (N, g) is the public key generated by the homomorphic encryption algorithm;

[0023] The encrypted reference topic is used to replace the encrypted main topic to construct a mirror ciphertext group.

[0024] Furthermore, the method of encrypting the additional information using the data hiding key Kw and embedding the encrypted additional information into the reserved space through homomorphic multiplication based on the mirror ciphertext group to complete hiding of the additional information in the service content resource includes:

[0025] The group selection key Kg is replaced by the key Kw of the additional information, and the key is hidden by the data Add additional information w Encrypted as

[0026] By the encrypted main theme And after encryption replacement Multiply them to complete the data hiding work and get the embedded hidden encrypted main theme c' h '; The additional information is embedded into at least three bit planes of the host subject resource in the homomorphic encryption domain; the encrypted subject matrix is ​​partitioned into E[I”] A , E[I”] B , E[I”] C , E[I”] is the encrypted subject content resource after constructing the mirror ciphertext group.

[0027] Furthermore, the generating corresponding additional information according to the metadata and the service information includes: fusing features of the metadata and the service information to obtain the corresponding additional information.

[0028] In a second aspect, the present invention provides a content resource recovery method based on the Pailier cryptographic system, the method is used to recover content resources encrypted using the content resource encryption method based on the Pailier cryptographic system described in the first aspect of the present invention, and is characterized in that:

[0029] Users use different keys to recover different data from encrypted content resources according to their own permissions; permissions include partial permissions and full permissions;

[0030] Users with partial permissions can use private keys to decrypt encrypted content resources and obtain content resources with hidden additional information for consumption;

[0031] A user with full permissions can use the hidden data key and hidden data parameters to extract the original service content resource and additional information of the content resource from the encrypted content resource.

[0032] Furthermore, the user with full authority uses the hidden data key and the hidden data parameter to extract the original service content resource and the additional information of the content resource from the encrypted content resource, including:

[0033] Step 1: Use the decryption method of the Pailler cryptosystem to process the received ciphertext content subject resource and extract the ciphertext pair of hidden data (c' h ',c r );

[0034] Step 2: Apply the modular inverse method to recover the encrypted weights and E[s w ];

[0035] Step 3: Using the homomorphic segmentation method, c r Extract hidden data from the encrypted domain as a reference;

[0036] Step 4: Using the data hiding key and group parameters, the user can obtain the corresponding r sw , and then even without the key, the corresponding ciphertext s can be obtained by looking up the mapping graph w ;

[0037] Step 5: Once the ciphertext s w After being calculated, the n-bit additional data can be obtained using the decryption strategy under the homomorphic encryption framework; by traversing all groups, all the additional data can be obtained, and then the original content resources and additional data can be obtained using the replacement key.

[0038] In a third aspect, the present invention provides a content resource encryption device based on the Pailier cryptographic system, which is used to execute a content resource encryption method based on the Pailier cryptographic system described in the first aspect of the present invention.

[0039] In a fourth aspect, the present invention provides a content resource recovery device based on the Pailier cryptographic system, characterized in that the device is used to execute a content resource recovery method based on the Pailier cryptographic system described in the second aspect of the present invention.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention adopts a data-recoverable content resource encryption method to encrypt service content resources, which can not only realize the copyright protection of service content, but also track and prove the encrypted content, which helps to reduce or avoid the negative impact of AIGC personalized customized content. The present invention first uses a self-embedding strategy to calculate the reserved space for embedding additional information, and uses the Pailler cryptographic system to operate the subject word vector matrix of the service content resource to construct a corresponding mirror ciphertext group. Then the present invention fuses the metadata corresponding to the service content resource and the content service information to form additional information, encrypts the additional information using a data hiding key, and embeds the additional information into the reserved space through homomorphic multiplication, completes the service content resource encryption and transmits the corresponding information to the user according to the user's authority, so as to achieve the purpose of copyright protection of content resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of the principles of a content resource encryption method and a recovery method based on a Pailier cryptographic system provided in an embodiment of the present invention; DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0044] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0045] In the description of the present application, the term "for example" is used to mean "used as an example, illustration or description". Any embodiment described as "for example" in the present application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any technician in the field to implement and use the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid unnecessary details to obscure the description of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0046] like Figure 1 As shown, an embodiment of the present invention provides a content resource encryption and recovery method based on the Pailier cryptographic system, comprising:

[0047] S1, extracting service content resources, metadata used to describe the service content resources, and service information corresponding to the service content resources from a content resource library.

[0048] Among them, service content resources are text content with complete chapter structure suitable for user consumption. Metadata is data stored in the content resource library to describe consumer content resources, including but not limited to content providers, core themes, claims (referring to the rights of intellectual property content agreed upon by consumers and content providers), charging strategies, etc. Service information is the information that should be provided when providing consumer content resources to users, including but not limited to user information, service time, and consumer content product form; the user information should include but not limited to user type, user name, and content consumption permissions.

[0049] S2, generating a corresponding theme matrix according to the service content resources, and generating corresponding additional information according to the metadata and service information.

[0050] The generating of the corresponding theme matrix according to the service content resources includes:

[0051] Performing chapter structure and semantic analysis on the service content resources to generate a set of ordered consumer content resource blocks; traversing all consumer content resource blocks, performing semantic analysis on each consumer content resource block to generate a corresponding theme word vector; constructing a theme matrix with a capacity of L*R based on the theme word vector.

[0052] The chapter structure analysis refers to dividing the consumption content generation resources into chapters using but not limited to a depth-first search spanning tree algorithm.

[0053] The generating corresponding additional information according to the metadata and the service information includes: fusing features of the metadata and the service information to obtain the corresponding additional information.

[0054] S3, utilizes the self-embedding strategy to create the reserved space required for embedding additional information in the subject matrix, and uses the Pailler cryptographic system to operate on the subject matrix of the service content resource to construct the corresponding mirror ciphertext group.

[0055] Specifically, this step includes the following sub-steps:

[0056] S3.1, divide the subject matrix into I A and I A two non-overlapping parts, and further I A Divided into I C and I B , where I C The capacity is L C *R C , the rest is I B , L C , R C All are multiples of 2;

[0057] S3.2, to I A The target groups are grouped, each group contains a reference topic and T main topics, and the group selection key Kg is used to select some groups as target groups; the target group selection method includes but is not limited to random selection; the main topic T should be as close to the reference topic as possible. When there are many reference topics, the minimum mean square error method can be used to determine it, but it is not limited to it.

[0058] S3.3, Extraction I A Reference topics and main topics for each group in I B The value of the least significant bit of each topic in generates the bit set b = {b A ,b B}, where b A = {b r ,b h}, b r 、b h The least significant bits of the reference topic and the main topic are represented by b B I B The least significant bit set of each topic in . This substep includes the following:

[0059] Step 1: Put I C There are two types of topics: reserved topics and reserved topic I wThe reserved topics remain unchanged throughout the self-embedding and resource recovery process and are used to predict the corresponding reserved topics I w ;

[0060] Step 2: Pass the reserved topic I w The four neighbor topics are used to estimate the reserved topic

[0061] Using but not limited to interpolation techniques to calculate I w The predicted value of I wp ;

[0062] Step 3: Calculate I w The prediction error e w =I wp -I w ;

[0063] Step 4: Wheel shift prediction error e w Histogram of the bit b is inserted into I C The specific steps of this process are as follows:

[0064] For each round of embedding, find the top two points in the prediction error histogram, and the left point is recorded as L p , the point on the right is denoted as R p , use these two points to divide the error histogram into the left part, the middle part and the right part;

[0065] Find the zero points of the left and right parts, denoted by L z and R z , using but not limited to the additive prediction error extension method to embed the bit b into I C ;

[0066] Step 5: L z , R z , L p , R p , shift times n e The boundary map is first permuted using the self-embedding key and embedded into I by replacing the LSB b middle.

[0067] S3.4, Retention I A The least significant bits of the reference subject and main subject of each group are embedded in the reserved space required as additional information.

[0068] S3.5, for the topic matrix I(i,j)′ after creating the reserved space, randomly select an integer The topic matrix is ​​encrypted using the public key (N, g) as shown below:

[0069] c(i,j)=E[I(i,j)′,r(i,j)]=g I(i,j)′ r(i,j) N mod N 2

[0070] Where i≤L, j≤R, (N,g) is the public key generated by the homomorphic encryption algorithm; where c(i,j) is the ciphertext corresponding to I(i,j)′, i=1,2,…,L,j=1,2,…,R, and the encrypted information resource is E[I′];

[0071] S3.6, replace the encrypted main subject with the encrypted reference subject to construct a mirror ciphertext group.

[0072] S4, using the data hiding key Kw to encrypt the additional information, and based on the mirror ciphertext group, embed the encrypted additional information into the reserved space through homomorphic multiplication to complete the hiding of the additional information in the service content resource.

[0073] The group selection key Kg is replaced by the key Kw of the additional information, and the key is hidden by the data Add additional information w Encrypted as

[0074] By the encrypted main theme And after encryption replacement Multiply them to complete the data hiding work and get the embedded hidden encrypted main theme c' h '; The additional information is embedded into at least three bit planes of the host subject resource in the homomorphic encryption domain; the encrypted subject matrix is ​​partitioned into E[I”] A , E[I”] B , E[I”] C , E[I”] is the encrypted subject content resource after constructing the mirror ciphertext group.

[0075] S6: The user end can receive different information according to its authority, and restore different types of data according to the received information, so as to realize the hierarchical and classified authorization of service content, which specifically includes:

[0076] Illegal users can only receive encrypted content resources, but without the key and content resource related parameters, they cannot restore the encrypted service content resources;

[0077] Legitimate users will receive different data and keys according to their permissions, and then use the received data and keys to recover different information from the encrypted service content resources;

[0078] The above permissions include partial permissions and full permissions. The partial permissions can only restore service content resources, and the full permissions can not only restore service content resources, but also restore additional hidden information for subsequent use;

[0079] The partially authorized user uses the received private key to directly decrypt the received encrypted service content resource information, and obtains content resources that are highly similar to the original service content resources for consumption;

[0080] After receiving the hidden data key and the hidden data parameter, the full-power user can extract not only the service content resource but also the related additional information of the content resource from the received encrypted content resource for subsequent use. The specific steps include:

[0081] Step 1: Use the decryption method of the Pailler cryptosystem to process the received ciphertext content subject resource and extract the ciphertext pair of hidden data (c' h ',c r );

[0082] Step 2: Apply the modular inverse method to recover the encrypted weights and E[s w ];

[0083] Step 3: Using the homomorphic segmentation method, c r Extract hidden data from the encrypted domain as a reference;

[0084] Step 4: Using the data hiding key and group parameters, the user can obtain the corresponding r sw , and then even without the key, the corresponding ciphertext s can be obtained by looking up the mapping graph w ;

[0085] Step 5: Once the ciphertext s w After being calculated, the n-bit additional data can be obtained using the decryption strategy under the homomorphic encryption framework; by traversing all groups, all the additional data can be obtained, and then the original content resources and additional data can be obtained using the replacement key.

[0086] Although the embodiments or examples of the present disclosure have been described with reference to the accompanying drawings, it should be understood that the above-mentioned methods, systems and devices are merely exemplary embodiments or examples, and the scope of the present invention is not limited by these embodiments or examples, but only by the claims after authorization and their equivalent scope. Various elements in the embodiments or examples can be omitted or replaced by their equivalent elements. In addition, each step can be performed in an order different from that described in the present disclosure. Further, the various elements in the embodiments or examples can be combined in various ways. It is important that with the evolution of technology, many elements described herein can be replaced by equivalent elements that appear after the present disclosure.

Claims

1. A content resource encryption method based on the Pailier cryptographic system, characterized in that: include: Extracting service content resources, metadata used to describe the service content resources, and service information corresponding to the service content resources from a content resource library; Generate a corresponding theme matrix according to the service content resources, and generate corresponding additional information according to the metadata and service information; The self-embedding strategy is used to create the reserved space required for embedding additional information in the subject matrix, and the Pailler cryptographic system is used to operate the subject matrix of the service content resource to construct the corresponding mirror ciphertext group; The additional information is encrypted using the data hiding key Kw, and based on the mirror ciphertext group, the encrypted additional information is embedded into the reserved space through homomorphic multiplication to complete the hiding of the additional information in the service content resource.

2. The encryption method according to claim 1, characterized in that: The generating of the corresponding theme matrix according to the service content resources includes: Performing text structure analysis on the service content resources to generate a set of ordered consumption content resource blocks; Traverse all consumption content resource blocks, perform semantic analysis on each consumption content resource block, and generate corresponding topic word vectors; A topic matrix with a capacity of L*R is constructed according to the topic word vector.

3. The encryption method according to claim 2, characterized in that: The self-embedding strategy described above is used to create a reserved space in the topic matrix required for embedding additional information, including: Divide the topic matrix into I A and I A two non-overlapping parts, and further I A Divided into I C and I B , where I C The capacity is L C *R C , the rest is I B , L C , R C All are multiples of 2; to I A Perform grouping, each group contains a reference topic and T main topics, and use the group selection key Kg to select some groups as target groups; Extraction I A Reference topics and main topics for each group in I B The value of the least significant bit of each topic in generates the bit set b = {b A ,b B }, where b A = {b r ,b h }, b r , b h The least significant bits of the reference topic and the main topic are represented by b B I B The least significant bits of each topic in ; The bit set b is embedded into IC using the additive prediction error expansion method, and I is retained. A The least significant bits of the reference subject and main subject of each group are embedded in the reserved space required as additional information.

4. The encryption method according to claim 3, characterized in that: The Pailler cryptographic system is used to operate the subject matrix of the service content resource to construct the corresponding mirror ciphertext group, including: After creating the reserved space for the topic matrix, randomly select an integer Encrypt the subject matrix using the public key (N, g), where i ≤ L, j ≤ R, and (N, g) is the public key generated by the homomorphic encryption algorithm; The encrypted reference topic is used to replace the encrypted main topic to construct a mirror ciphertext group.

5. The encryption method according to claim 4, characterized in that: The method of encrypting the additional information using the data hiding key Kw and embedding the encrypted additional information into the reserved space through homomorphic multiplication based on the mirror ciphertext group to complete hiding of the additional information in the service content resource includes: The group selection key Kg is replaced by the key Kw of the additional information, and the key is hidden by the data Add additional information w Encrypted as By the encrypted main topic And after encryption replacement Multiply them to complete the data hiding work and get the embedded hidden encrypted main theme c' h '; The additional information is embedded into at least three bit planes of the host subject resource in the homomorphic encryption domain; the encrypted subject matrix is ​​partitioned into E[I”] A , E[I”] B , E[I”] C , E[I”] is the encrypted subject content resource after constructing the mirror ciphertext group.

6. The encryption method according to claim 1, characterized in that: The generating corresponding additional information according to the metadata and the service information includes: fusing features of the metadata and the service information to obtain the corresponding additional information.

7. A content resource recovery method based on the Pailier cryptographic system, the method being used to recover content resources encrypted using the content resource encryption method based on the Pailier cryptographic system as claimed in any one of claims 1 to 6, characterized in that: Users use different keys to recover different data from encrypted content resources according to their own permissions; permissions include partial permissions and full permissions; Users with partial permissions can use private keys to decrypt encrypted content resources and obtain content resources with hidden additional information for consumption; A user with full permissions can use the hidden data key and hidden data parameters to extract the original service content resource and additional information of the content resource from the encrypted content resource.

8. The content resource recovery method according to claim 7, characterized in that: The user with full authority uses the hidden data key and the hidden data parameter to extract the original service content resource and additional information of the content resource from the encrypted content resource, including: Step 1: Use the decryption method of the Pailler cryptosystem to process the received ciphertext content subject resource and extract the ciphertext pair of hidden data (c' h ',c r ); Step 2: Apply the modular inverse method to recover the encrypted weights and E[s w ]; Step 3: Using the homomorphic segmentation method, c r Extract hidden data from the encrypted domain as a reference; Step 4: Using the data hiding key and group parameters, the user can obtain the corresponding r sw , and then even without the key, the corresponding ciphertext s can be obtained by looking up the mapping graph w ; Step 5: Once the ciphertext s w After being calculated, the n-bit additional data can be obtained using the decryption strategy under the homomorphic encryption framework; by traversing all groups, all the additional data can be obtained, and then the original content resources and additional data can be obtained using the replacement key.

9. A content resource encryption device based on the Pailier cryptographic system, characterized in that: The device is used to execute a content resource encryption method based on the Pailier cryptographic system as described in any one of claims 1-6.

10. A content resource recovery device based on the Pailier cryptographic system, characterized in that: The device is used to execute a content resource recovery method based on the Pailier cryptographic system as described in any one of claims 7-8.

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