Shared domain reversible information hiding method and system based on re-encryption

Abstract

The invention discloses a shared domain reversible information hiding method and system based on re-encryption, and relates to the technical field of information hiding, and the method comprises the steps: carrying out the encryption of a plaintext carrier according to an encryption key and a secret sharing encryption algorithm, and obtaining a plurality of preliminary ciphertext carriers; according to the encryption key and a secret sharing encryption algorithm, encrypting the plurality of preliminary ciphertext carriers to obtain a plurality of final ciphertext carriers; wherein the determination process of each part of the final ciphertext carrier is as follows: selecting a second preset number of preliminary ciphertext carriers, and encrypting the second preset number of preliminary ciphertext carriers according to an encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; and finally, sending the plurality of parts of final ciphertext carriers to a plurality of information hiding parties. The data embedding difficulty of the ciphertext carrier can be reduced, and the generation of the ciphertext carrier can be dynamically adjusted.

Description

Technical Field

[0001] This application relates to the field of information hiding technology, and in particular to a reversible information hiding method and system in a shared domain based on re-encryption. Background Art

[0002] In the ciphertext domain reversible information hiding technology, first, the plaintext carrier is encrypted into a ciphertext carrier and sent to a single information hiding party for data embedding. Secondly, data is embedded into the ciphertext carrier to generate a ciphertext carrier with embedded data. Finally, the embedded data is extracted from the ciphertext carrier with embedded data and the original plaintext carrier is restored. The ciphertext domain reversible information hiding technology is mainly used for tamper detection and integrity authentication of carriers.

[0003] To improve the recoverability of the plaintext carrier, the shared domain reversible information hiding technology is proposed. It first encrypts the plaintext carrier into multiple ciphertext carriers and sends them to multiple different information hiding parties for data embedding. Then, multiple pieces of data are independently embedded into multiple ciphertext carriers respectively to generate corresponding ciphertext carriers with embedded data. Finally, the receiver selects any sufficient number of ciphertext carriers with embedded data from the information hiding parties to extract the embedded data and restore the original plaintext carrier. The shared domain reversible information hiding technology can ensure that even if some information hiding parties are attacked and unable to provide ciphertext carriers with embedded data, the receiver can obtain ciphertext carriers with embedded data from the information hiding parties that have not been attacked to achieve data extraction and plaintext carrier restoration. However, the shared domain reversible information hiding technology still has the following disadvantages: it is difficult to directly use the ciphertext carrier for data embedding, and it is impossible to dynamically adjust the generation of the ciphertext carrier. Summary of the Invention

[0004] The purpose of this application is to provide a reversible information hiding method and system in a shared domain based on re-encryption, which can reduce the difficulty of data embedding in the ciphertext carrier and achieve dynamic adjustment of the generation of the ciphertext carrier.

[0005] To achieve the above purpose, this application provides the following solutions: In a first aspect, this application provides a reversible information hiding method in a shared domain based on re-encryption, including: Obtain a plaintext carrier.

[0006] Encrypt the plaintext carrier according to an encryption key and a secret sharing encryption algorithm to obtain a number of preliminary ciphertext carriers; wherein, the first preset number of the preliminary ciphertext carriers is used to restore the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers.

[0007] Encrypt a number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain a number of final ciphertext carriers; wherein, the number of the final ciphertext carriers is the same as the number of the preliminary ciphertext carriers; the determination process of each final ciphertext carrier is as follows: select a second preset number of the preliminary ciphertext carriers, and encrypt the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of the second preset number is less than the number of the first preset number.

[0008] Send a number of the final ciphertext carriers to a number of information hiding parties; the number of the information hiding parties is the same as the number of the final ciphertext carriers; each information hiding party is used to perform data embedding on one final ciphertext carrier to obtain a ciphertext carrier with embedded data, and send the ciphertext carrier with embedded data to the receiving party; the receiving party is used to perform data extraction and carrier restoration according to a third preset number of the ciphertext carriers with embedded data to obtain the embedded data and the plaintext carrier; the number of the third preset number is equal to the number of the first preset number minus the number of the second preset number plus 1.

[0009] In a second aspect, the present application provides another reversible information hiding method in a shared domain based on re-encryption, including: The encrypting party obtains a plaintext carrier.

[0010] The encrypting party encrypts the plaintext carrier according to an encryption key and a secret sharing encryption algorithm to obtain a number of preliminary ciphertext carriers; wherein, a first preset number of the preliminary ciphertext carriers are used to restore the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers.

[0011] The encrypting party encrypts a number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain a number of final ciphertext carriers; wherein, the number of the final ciphertext carriers is the same as the number of the preliminary ciphertext carriers; the determination process of each final ciphertext carrier is as follows: select a second preset number of the preliminary ciphertext carriers, and encrypt the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of the second preset number is less than the number of the first preset number.

[0012] The encrypting party sends a number of the final ciphertext carriers to a number of information hiding parties; the number of the information hiding parties is the same as the number of the final ciphertext carriers.

[0013] Each of the information hiding parties embeds data into one of the final ciphertext carriers to obtain an encrypted ciphertext carrier, and sends the encrypted ciphertext carrier to the receiver.

[0014] The receiver extracts data and recovers the carrier based on the third preset number of the encrypted ciphertext carriers to obtain the embedded data and the plaintext carrier; the number of the third preset number is equal to the number of the first preset number minus the number of the second preset number plus 1.

[0015] Thirdly, the present application provides a re-encryption-based reversible information hiding system in a shared domain, including: The encrypting party is used for: Obtaining a plaintext carrier.

[0016] Encrypting the plaintext carrier according to an encryption key and a secret sharing encryption algorithm to obtain a plurality of preliminary ciphertext carriers; wherein, the first preset number of the preliminary ciphertext carriers is used to recover the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers.

[0017] Encrypting a plurality of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain a plurality of final ciphertext carriers; wherein, the number of the final ciphertext carriers is the same as the number of the preliminary ciphertext carriers; the determination process of each of the final ciphertext carriers is: selecting the second preset number of the preliminary ciphertext carriers, and encrypting the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of the second preset number is less than the number of the first preset number.

[0018] Sending a plurality of the final ciphertext carriers to a plurality of information hiding parties; the number of the information hiding parties is the same as the number of the final ciphertext carriers.

[0019] Each of the information hiding parties embeds data into one of the final ciphertext carriers to obtain an encrypted ciphertext carrier, and sends the encrypted ciphertext carrier to the receiver.

[0020] The receiver is used for extracting data and recovering the carrier based on the third preset number of the encrypted ciphertext carriers to obtain the embedded data and the plaintext carrier; the number of the third preset number is equal to the number of the first preset number minus the number of the second preset number plus 1.

[0021] According to the specific embodiments provided by the present application, the present application has the following technical effects: The present application provides a reversible information hiding method and system in a shared domain based on re-encryption. First, according to an encryption key and a secret sharing encryption algorithm, a plaintext carrier is encrypted to obtain several preliminary ciphertext carriers; then, according to the encryption key and the secret sharing encryption algorithm, the several preliminary ciphertext carriers are encrypted to obtain several final ciphertext carriers; wherein, the determination process of each final ciphertext carrier is: select a second preset number of preliminary ciphertext carriers, and according to the encryption key and the secret sharing encryption algorithm, encrypt the second preset number of preliminary ciphertext carriers to obtain the final ciphertext carrier; finally, send the several final ciphertext carriers to several information hiding parties. Through the above technical solution of two-time encryption (i.e., re-encryption), the present application enables each information hiding party to receive a final ciphertext carrier containing the information of the second preset number of preliminary ciphertext carriers. Compared with the prior art that uses one-time encryption, each information hiding party receives a ciphertext carrier containing only one ciphertext carrier information. The present application can effectively reduce the difficulty of data embedding by the information hiding party for the ciphertext carrier; moreover, in the present application, the value of the second preset number can be adjusted according to requirements during the generation process of the ciphertext carrier to balance the difficulty of data embedding and the data volume of each final ciphertext carrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0023] Figure 1 It is a schematic flowchart of a reversible information hiding method in a shared domain based on re-encryption provided by an embodiment of the present application; Figure 2 It is a schematic diagram of a reversible information hiding system in a shared domain based on re-encryption provided by an embodiment of the present application; Figure 3 It is a schematic diagram of a reversible information hiding model in a shared domain based on re-encryption provided by an embodiment of the present application; Figure 4 It is a schematic diagram of the structure of a computer device provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0025] Currently, the following drawbacks exist in shared-domain reversible information hiding: (1) The ciphertext carrier is difficult to directly use for data embedding. The process of encrypting the plaintext carrier into the ciphertext carrier using a secure encryption algorithm will destroy the correlation of the carrier, that is, the correlation of the plaintext carrier is dispersed into different ciphertext carriers; and the generated ciphertext carriers are held by different information hiding parties, that is, the ciphertext carriers cannot achieve data embedding by performing ciphertext operations, which makes it difficult for the information hiding party to directly embed data into the ciphertext carrier.

[0026] (2) The generation of the ciphertext carrier cannot be dynamically adjusted. The generation of the ciphertext carrier is determined by the encryption algorithm and the plaintext carrier. When a specific encryption algorithm is used to encrypt the plaintext carrier, the generated ciphertext carrier is determined, and then the dependence relationship between information hiding and the ciphertext carrier is determined.

[0027] To make the above objects, features, and advantages of the present application more obvious and understandable, the following further detailed description of the present application will be made with reference to the accompanying drawings and specific embodiments.

[0028] In an exemplary embodiment, as Figure 1 shown, the present application provides a shared-domain reversible information hiding method based on re-encryption, including the following steps: Step S101: Obtain a plaintext carrier.

[0029] Step S102: Encrypt the plaintext carrier according to an encryption key and a secret sharing encryption algorithm (abbreviated as the secret sharing algorithm) to obtain a plurality of preliminary ciphertext carriers (also referred to as ciphertext carriers in this article); wherein, the first preset number of the preliminary ciphertext carriers is used to recover the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers.

[0030] Step S103: Encrypt several copies of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain several copies of final ciphertext carriers; wherein, the number of copies of the final ciphertext carriers is the same as that of the preliminary ciphertext carriers; the determination process of each copy of the final ciphertext carrier is as follows: Select a second preset number of the preliminary ciphertext carriers, and encrypt the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of copies of the second preset number is less than the number of copies of the first preset number.

[0031] Step S102 and Step S103 together constitute the re-encryption technology (abbreviated as re-encryption), also known as the re-encryption technology of double secret sharing.

[0032] Step S104: Send several copies of the final ciphertext carriers to several information hiding parties; the number of information hiding parties is the same as the number of copies of the final ciphertext carriers; each information hiding party is used to perform data embedding on a copy of the final ciphertext carrier to obtain a ciphertext carrier with embedded data, and send the ciphertext carrier with embedded data to the receiving party; the receiving party is used to perform data extraction and carrier recovery according to a third preset number of the ciphertext carriers with embedded data to obtain the embedded data and the plaintext carrier; the number of copies of the third preset number is equal to the number of copies of the first preset number minus the number of copies of the second preset number plus 1.

[0033] As an optional implementation manner, the determination process of each copy of the final ciphertext carrier is as follows: Determine the final ciphertext carrier by using the following mathematical model: ; Wherein, represents the th copy of the final ciphertext carrier; represents the secret sharing encryption algorithm; represents the encryption key; represents the second preset number of preliminary ciphertext carriers; represents the th copy of the preliminary ciphertext carrier; ; represents taking the modulus; represents the second preset number; represents the number of copies of the final ciphertext carrier, which is also the number of copies of the preliminary ciphertext carrier.

[0034] In this embodiment, in terms of performing data embedding on a copy of the final ciphertext carrier, the operations performed by the information hiding party specifically include: According to the hidden key and the data to be embedded, use the ciphertext operation embedding algorithm to embed data into the final ciphertext carrier, so as to obtain the encrypted ciphertext carrier containing the data.

[0035] Further, in terms of extracting the embedded data according to the third preset number of copies of the encrypted ciphertext carrier containing the data, the operations performed by the receiving party specifically include: According to the hidden key, use the ciphertext operation extraction algorithm to extract data from each copy of the encrypted ciphertext carrier containing the data, so as to obtain the embedded data corresponding to each copy of the encrypted ciphertext carrier containing the data.

[0036] In this embodiment, in terms of restoring the plaintext carrier according to the third preset number of copies of the encrypted ciphertext carrier containing the data, the operations performed by the receiving party specifically include: According to the decryption key and the secret sharing decryption algorithm, perform a decryption operation on the third preset number of copies of the encrypted ciphertext carrier containing the data to obtain the fourth preset number of copies of the preliminary ciphertext carrier; the fourth preset number of copies is greater than or equal to the first preset number of copies; wherein, among the fourth preset number of copies of the preliminary ciphertext carriers, each preliminary ciphertext carrier is different from other preliminary ciphertext carriers.

[0037] Select the first preset number of copies of the preliminary ciphertext carriers from the fourth preset number of copies of the preliminary ciphertext carriers.

[0038] According to the decryption key and the secret sharing decryption algorithm, perform a decryption operation on the first preset number of copies of the preliminary ciphertext carriers to obtain the plaintext carrier.

[0039] That is, the receiving party restores the plaintext carrier through the above double secret sharing decryption technology.

[0040] As an optional implementation manner, the secret sharing encryption algorithm includes Shamir threshold secret sharing encryption algorithm and secret sharing encryption algorithm based on the Chinese Remainder Theorem.

[0041] Further, when the secret sharing encryption algorithm is the Shamir threshold secret sharing encryption algorithm, the secret sharing decryption algorithm is the Lagrange polynomial interpolation algorithm. When the secret sharing encryption algorithm is the secret sharing encryption algorithm based on the Chinese Remainder Theorem, the secret sharing decryption algorithm is the algorithm for solving congruence equations.

[0042] In another exemplary embodiment of the present application, another reversible information hiding method in the shared domain based on re-encryption is provided, including the following steps: Step S201: The encrypting party obtains the plaintext carrier.

[0043] Step S202: The encrypting party encrypts the plaintext carrier according to the encryption key and the secret sharing encryption algorithm to obtain several preliminary ciphertext carriers; among them, the first preset number of the preliminary ciphertext carriers is used to recover the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers.

[0044] Step S203: The encrypting party encrypts several of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain several final ciphertext carriers; among them, the number of the final ciphertext carriers is the same as the number of the preliminary ciphertext carriers; the determination process of each final ciphertext carrier is: select the second preset number of the preliminary ciphertext carriers, and encrypt the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of the second preset number is less than the number of the first preset number.

[0045] Step S204: The encrypting party sends several of the final ciphertext carriers to several information hiding parties; the number of the information hiding parties is the same as the number of the final ciphertext carriers.

[0046] Step S205: Each information hiding party embeds data into one of the final ciphertext carriers to obtain a ciphertext carrier with embedded data, and sends the ciphertext carrier with embedded data to the receiving party.

[0047] Step S206: The receiving party performs data extraction and carrier recovery according to the third preset number of the ciphertext carriers with embedded data to obtain the embedded data and the plaintext carrier; the number of the third preset number is equal to the number of the first preset number minus the number of the second preset number plus 1.

[0048] Based on the same inventive concept, an embodiment of the present application further provides a re-encryption-based reversible information hiding system in a shared domain for implementing the above-mentioned re-encryption-based reversible information hiding method in a shared domain. The implementation solutions provided by the system to solve problems are similar to the implementation solutions described in the above method. Therefore, the specific limitations in one or more embodiments of the re-encryption-based reversible information hiding system provided below can refer to the limitations on the re-encryption-based reversible information hiding method in the above text, and will not be repeated here.

[0049] In an exemplary embodiment, as Figure 2 shown, a re-encryption-based reversible information hiding system in a shared domain is provided, including: The encrypting party M1 is used for: Obtain a plaintext carrier.

[0050] Encrypt the plaintext carrier according to the encryption key and the secret sharing encryption algorithm to obtain several preliminary ciphertext carriers; wherein, the first preset number of the preliminary ciphertext carriers is used to recover the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers.

[0051] Encrypt several of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain several final ciphertext carriers; wherein, the number of the final ciphertext carriers is the same as the number of the preliminary ciphertext carriers; the determination process of each final ciphertext carrier is: select the second preset number of the preliminary ciphertext carriers, and encrypt the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of the second preset number is less than the number of the first preset number.

[0052] Send several of the final ciphertext carriers to several information hiding parties M2; the number of the information hiding parties is the same as the number of the final ciphertext carriers.

[0053] Each information hiding party M2 is used to perform data embedding on one of the final ciphertext carriers to obtain a ciphertext carrier with embedded data, and send the ciphertext carrier with embedded data to the receiving party M3.

[0054] The receiving party M3 is used to perform data extraction and carrier recovery according to the third preset number of the ciphertext carriers with embedded data to obtain the embedded data and the plaintext carrier; the number of the third preset number is equal to the number of the first preset number minus the number of the second preset number plus 1.

[0055] In another exemplary embodiment, the encrypting party is the owner of the plaintext carrier (referred to as the owner). In this embodiment, the reversible information hiding system in the shared domain based on re-encryption is also referred to as the reversible information hiding model in the shared domain based on re-encryption. That is, this model consists of carrier encryption, data embedding, and data extraction and carrier recovery, which are respectively executed by the owner, the information hiding party, and the receiving party. See Figure 3 。

[0056] In the process of carrier encryption, the owner encrypts the plaintext carrier into multiple final ciphertext carriers by using the re-encryption technology of double secret sharing according to the encryption key. The generated multiple final ciphertext carriers are sent to multiple different information hiding parties for data embedding. Specifically, the owner first encrypts the plaintext carrier into ciphertext carriers by using the secret sharing algorithm, wherein, ciphertext carriers can recover the plaintext carrier. For the plaintext carrier , the mathematical expression of its secret sharing encryption process is as follows: ; Among them, is the secret sharing algorithm using the encryption key , is the generated copies of ciphertext carriers. The secret sharing algorithm here can be selected such as the Shamir threshold secret sharing algorithm, the secret sharing algorithm based on the Chinese Remainder Theorem, etc. Then select copies of the ciphertext carriers with a safe quantity as the input, and use the secret sharing algorithm again for encryption to generate copies of the final ciphertext carriers. For the selected copies of ciphertext carriers , the secret sharing encryption process is referred to the previous embodiments. Finally, send the generated copies of the final ciphertext carriers to different information hiding parties for data embedding.

[0057] In the data embedding process, each information hiding party embeds the data into the final ciphertext carrier according to the hiding key to generate the encrypted ciphertext carrier with data (realize data embedding), and authorizes part of the encrypted ciphertext carrier with data to the receiver for data extraction and carrier recovery. Suppose the data to be embedded into the th (copy) of the final ciphertext carrier is . For the final ciphertext carrier , the mathematical expression of data embedding is as follows: ; Among them, represents the th hiding key, represents the ciphertext operation embedding algorithm using the hiding key, represents the generated th copy of the encrypted ciphertext carrier with data.

[0058] In the data extraction and carrier recovery process, the receiver performs data extraction and carrier recovery according to the selected sufficient number of encrypted ciphertext carriers with data. Among them, on the one hand, the receiver extracts the embedded data according to the hiding key and uses the ciphertext operation; on the other hand, the receiver decrypts the key and uses the double secret sharing decryption to recover the plaintext carrier.

[0059] In the data extraction and carrier recovery process, the receiver needs to use any copies of ciphertext carriers to recover the plaintext carrier. Since each encrypted ciphertext carrier with data contains copies of ciphertext carrier information, it is possible to select copies of encrypted ciphertext carriers with data for recovering the plaintext carrier and extracting the data embedded therein at the same time. Suppose any selected The encrypted text carrier is . For data extraction, the receiver uses the encrypted text operation extraction algorithm to extract the embedded data from the encrypted text carrier, and its mathematical expression is as follows: ; where represents the encrypted text operation extraction algorithm using the hidden key , is the th extracted data, . For carrier recovery, the receiver first performs secret sharing decryption on the encrypted text carrier to obtain the ciphertext carrier, and its mathematical expression is as follows: ; where represents the secret sharing decryption algorithm using the decryption key , is the th ciphertext carrier generated by decryption. Secondly, the receiver performs secret sharing decryption on the ciphertext carriers generated by decryption to recover the plaintext carrier , and its mathematical expression is as follows: .

[0060] If the Shamir threshold secret sharing algorithm is used to encrypt the plaintext carrier during the carrier encryption process, the corresponding secret sharing decryption algorithm is Lagrangian polynomial interpolation; if the secret sharing algorithm based on the Chinese Remainder Theorem is used to encrypt the plaintext carrier during the carrier encryption process, the corresponding secret sharing decryption algorithm is solving congruence equations.

[0061] To facilitate the understanding of the above process, the following example is given for further illustration: For the plaintext carrier , after the first encryption, 10 (i.e., ) (preliminary) ciphertext carriers are obtained; among them, any 5 (i.e., ) ciphertext carriers can be used to recover the plaintext carrier. During the second encryption, each final ciphertext carrier is generated based on any 3 (i.e., ) ciphertext carriers; for example, the first final ciphertext carrier is generated based on the first to third ciphertext carriers, the second final ciphertext carrier is generated based on the second to fourth ciphertext carriers,..., and the tenth final ciphertext carrier is generated based on the tenth to second (i.e., the tenth, first, and second) ciphertext carriers.

[0062] Each information hiding party embeds data into a final ciphertext carrier to obtain a corresponding encrypted ciphertext carrier. For example, the 1st information hiding party embeds data into the 1st final ciphertext carrier to obtain the 1st encrypted ciphertext carrier, the 2nd information hiding party embeds data into the 2nd final ciphertext carrier to obtain the 2nd encrypted ciphertext carrier, and so on. The 10th information hiding party embeds data into the 10th final ciphertext carrier to obtain the 10th encrypted ciphertext carrier.

[0063] The receiver can perform data extraction or carrier recovery based on any 3 (i.e., ) encrypted ciphertext carriers. For example, for the 1st - 3rd encrypted ciphertext carriers, on the one hand, data extraction is performed respectively to obtain the corresponding data. On the other hand, based on the decryption key and the 1st - 3rd encrypted ciphertext carriers, decryption can be performed to obtain the 1st - 5th ciphertext carriers, and then the plaintext carrier can be recovered based on the 1st - 5th ciphertext carriers. Of course, in other cases, such as for the 1st, 3rd, and 5th encrypted ciphertext carriers, the 1st - 7th ciphertext carriers can be obtained, and then any 5 ciphertext carriers can be selected from these 1st - 7th ciphertext carriers to recover the plaintext carrier. .

[0064] The present application has the following beneficial effects: (1) The ciphertext carrier is easy for data embedding. Under the condition of ensuring security, the final ciphertext carrier generated by each execution of the double - secret - sharing encryption is sent to a single information hiding party. That is, each information hiding party can independently perform ciphertext operations on the corresponding final ciphertext carrier, which makes it easy for each information hiding party to embed data into the ciphertext carrier. For each information hiding party, the more plaintext carrier information contained in the ciphertext carrier used for data embedding (corresponding to the final ciphertext carrier of the present application), the easier it is to embed data. In the present application, when encrypting for the second time, each obtained final ciphertext carrier is generated based on ciphertext carriers, so it contains more plaintext carrier information, and thus can effectively reduce the difficulty of data embedding.

[0065] (2) Adaptive ciphertext carrier control. During the double - secret - sharing encryption process, the generation of the final ciphertext carrier is adaptively controlled by dynamically adjusting the input parameters. That is, by selecting secure - quantity ciphertext carriers as input and encrypting again using the secret - sharing algorithm to generate final ciphertext carriers. The input parameters refer to secure - quantity ciphertext carriers, where can be dynamically adjusted, and selecting different parameters will generate different final ciphertext carriers. However, The larger the value of , the larger the data volume of each final ciphertext carrier obtained.

[0066] It can also be understood in this way: The ciphertext carrier in the existing method is determined by the input (plaintext carrier) and the encryption algorithm; the re-encryption technology used in this method changes the input, that is, the plaintext carrier becomes multiple secure quantity ciphertext carriers, which can be dynamically adjusted, so the output final ciphertext carrier will also change.

[0067] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structural diagram can be as Figure 4 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store plaintext carrier data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a reversible information hiding method in a shared domain based on re-encryption.

[0068] Those skilled in the art can understand that Figure 4 the structure shown in

[0069] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, it implements a reversible information hiding method in a shared domain based on re-encryption.

[0070] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, it implements a reversible information hiding method in a shared domain based on re-encryption.

[0071] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0072] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the various embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0073] The databases involved in the various embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the various embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0074] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0075] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on the present application.

Claims

1. A reversible information hiding method in a shared domain based on re-encryption, characterized in that, The reversible information hiding method in a shared domain based on re-encryption includes: Obtain a plaintext carrier; Encrypt the plaintext carrier according to an encryption key and a secret sharing encryption algorithm to obtain several preliminary ciphertext carriers; wherein, the first preset number of the preliminary ciphertext carriers is used to recover the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers; Encrypt several of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain several final ciphertext carriers; wherein, the number of the final ciphertext carriers is the same as the number of the preliminary ciphertext carriers; the determination process of each final ciphertext carrier is: select the second preset number of the preliminary ciphertext carriers, and encrypt the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of the second preset number is less than the number of the first preset number; Send several of the final ciphertext carriers to several information hiding parties; the number of the information hiding parties is the same as the number of the final ciphertext carriers; each information hiding party is used to perform data embedding on one of the final ciphertext carriers to obtain an encrypted ciphertext carrier containing data, and send the encrypted ciphertext carrier containing data to a receiving party; the receiving party is used to perform data extraction and carrier recovery according to the third preset number of the encrypted ciphertext carriers containing data to obtain the embedded data and the plaintext carrier; the number of the third preset number is equal to the number of the first preset number minus the number of the second preset number plus 1.

2. The reversible information hiding method in a shared domain based on re-encryption according to claim 1, characterized in that, The determination process of each final ciphertext carrier is: Determine the final ciphertext carrier by using the following mathematical model: ； Among them, represents the th final ciphertext carrier; represents the secret sharing encryption algorithm; represents the encryption key; represents the preliminary ciphertext carriers of the second preset number; represents the th preliminary ciphertext carrier; represents the th preliminary ciphertext carrier; represents the th preliminary ciphertext carrier; represents the th preliminary ciphertext carrier; ; represents modulo operation; represents the second preset number; represents the number of final ciphertext carriers.

3. The reversible information hiding method in a shared domain based on re-encryption according to claim 1, wherein In terms of performing data embedding on one of the final ciphertext carriers, the operations performed by the information hiding party specifically include: Perform data embedding on the final ciphertext carrier according to a hiding key and the embedded data by using a ciphertext operation embedding algorithm to obtain the encrypted ciphertext carrier containing data.

4. The reversible information hiding method in a shared domain based on re-encryption according to claim 3, characterized in that, In terms of performing data extraction to obtain the embedded data according to the third preset number of the encrypted ciphertext carriers containing data, the operations performed by the receiving party specifically include: Perform data extraction on each of the encrypted ciphertext carriers containing data according to the hiding key by using a ciphertext operation extraction algorithm to obtain the embedded data corresponding to each of the encrypted ciphertext carriers containing data.

5. The reversible information hiding method in a shared domain based on re-encryption according to claim 1, characterized in that In terms of performing carrier recovery to obtain the plaintext carrier according to the third preset number of the encrypted ciphertext carriers containing data, the operations performed by the receiving party specifically include: Perform a decryption operation on the third preset number of the encrypted ciphertext carriers containing data according to a decryption key and a secret sharing decryption algorithm to obtain the fourth preset number of the preliminary ciphertext carriers; the fourth preset number is greater than or equal to the first preset number; Select the first preset number of the preliminary ciphertext carriers from the fourth preset number of the preliminary ciphertext carriers; Perform a decryption operation on the first preset number of the preliminary ciphertext carriers according to the decryption key and the secret sharing decryption algorithm to obtain the plaintext carrier.

6. The reversible information hiding method in a shared domain based on re-encryption according to claim 5, wherein The secret sharing encryption algorithm includes the Shamir threshold secret sharing encryption algorithm and the secret sharing encryption algorithm based on the Chinese Remainder Theorem.

7. The reversible information hiding method for a shared domain based on re-encryption according to claim 6, wherein When the secret sharing encryption algorithm is the Shamir threshold secret sharing encryption algorithm, the secret sharing decryption algorithm is the Lagrange polynomial interpolation algorithm.

8. The reversible information hiding method in a shared domain based on re-encryption according to claim 6, characterized in that When the secret sharing encryption algorithm is the secret sharing encryption algorithm based on the Chinese Remainder Theorem, the secret sharing decryption algorithm is the congruence equation solving algorithm.

9. A reversible information hiding method in a shared domain based on re-encryption, characterized in that, The re-encryption-based reversible information hiding method in the shared domain includes: The encrypting party obtains the plaintext carrier. The encrypting party encrypts the plaintext carrier according to the encryption key and the secret sharing encryption algorithm to obtain several preliminary ciphertext carriers; among them, the first preset number of the preliminary ciphertext carriers is used to recover the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers. The encrypting party encrypts several of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain several final ciphertext carriers; among them, the number of the final ciphertext carriers is the same as the number of the preliminary ciphertext carriers; the determination process of each final ciphertext carrier is: select the second preset number of the preliminary ciphertext carriers, and encrypt the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of the second preset number is less than the number of the first preset number. The encrypting party sends several of the final ciphertext carriers to several information hiding parties; the number of the information hiding parties is the same as the number of the final ciphertext carriers. Each information hiding party embeds data into one of the final ciphertext carriers to obtain the encrypted ciphertext carrier with data embedded, and sends the encrypted ciphertext carrier with data embedded to the receiving party. The receiving party extracts data and recovers the carrier according to the third preset number of the encrypted ciphertext carriers with data embedded to obtain the embedded data and the plaintext carrier; the number of the third preset number is equal to the number of the first preset number minus the number of the second preset number plus 1.

10. A reversible information hiding system in a shared domain based on re-encryption, characterized in that, The re-encryption-based reversible information hiding system in the shared domain includes: The encrypting party is used for: Obtaining the plaintext carrier. Encrypting the plaintext carrier according to the encryption key and the secret sharing encryption algorithm to obtain several preliminary ciphertext carriers; among them, the first preset number of the preliminary ciphertext carriers is used to recover the plaintext carrier; the number of the first preset number is greater than or equal to 2 and less than or equal to the number of the preliminary ciphertext carriers. Encrypt a number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain a number of final ciphertext carriers; wherein, the number of the final ciphertext carriers is the same as the number of the preliminary ciphertext carriers; the determination process of each final ciphertext carrier is as follows: select a second preset number of the preliminary ciphertext carriers, and encrypt the second preset number of the preliminary ciphertext carriers according to the encryption key and the secret sharing encryption algorithm to obtain the final ciphertext carrier; the number of the second preset number is less than the number of the first preset number. Send a number of the final ciphertext carriers to a number of information hiding parties; the number of the information hiding parties is the same as the number of the final ciphertext carriers. Each information hiding party is used to perform data embedding on one final ciphertext carrier to obtain an encrypted ciphertext carrier with data embedded therein, and send the encrypted ciphertext carrier with data embedded therein to the receiving party. The receiving party is used to perform data extraction and carrier restoration according to a third preset number of the encrypted ciphertext carriers with data embedded therein to obtain the embedded data and the plaintext carrier; the number of the third preset number is equal to the number of the first preset number minus the number of the second preset number plus 1.

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