Digital copyright protection method and system based on exchange password watermark and block chain

Abstract

The invention provides a digital copyright protection method and system based on an exchange password watermark and a block chain. The method comprises the following steps: firstly, enabling data to complete digital watermark embedding and extraction in a ciphertext state by utilizing the exchangeability of an exchange password watermark technology so as to avoid data leakage, and then utilizing a Merkle Tree structure to link and store data and watermark (fingerprint) operation domain information so as to complete data integrity verification and distribution traceability; data forgery is prevented, and the block chain storage overhead is reduced; in the traceability process, an interactive credible traceability algorithm is utilized to complete traceability of illegal distributors, the algorithm reduces a dispute range of a traceability calculation result under a chain through a watermark challenge-response protocol, and a block chain recalculates and verifies a result of the dispute range to realize credible traceability. The block chain records the data distribution information and the verification process in the whole process, it is guaranteed that the traceability evidence obtaining process is open and transparent, and traceability of users who illegally distribute and illegally use data is achieved on the premise that the data security is protected.

Description

Technical Field

[0001] The present invention belongs to the field of multimedia information security protection, and specifically relates to a digital copyright protection method that combines exchange password watermark technology with blockchain technology, which can be used for copyright protection and piracy tracing of digital media content. Background Art

[0002] The rapid development of internet technology has greatly facilitated the dissemination of multimedia data, but it has also led to rampant illegal copying and unauthorized use of data. Consequently, protecting the copyright of digital multimedia content has become a matter of great concern. Digital watermarking technology, by embedding copyright and user information within multimedia data, plays a vital role in digital copyright protection and tracing piracy. However, traditional digital watermarking methods rely heavily on third-party entities to perform digital watermarking operations to protect data copyright and trace piracy. This approach poses challenges in the trustworthiness of third-party entities, potentially leading to data leaks and malicious watermark removal.

[0003] Blockchain is a new distributed infrastructure that combines distributed data storage, cryptographic algorithms, peer-to-peer transmission, consensus mechanisms, and smart contracts. It boasts decentralization, transparency, tamper-resistance, and traceability. The emergence of blockchain technology presents new opportunities for resolving copyright issues. For example, its decentralized operation, consensus mechanism, tamper-resistance, and full traceability make it a fully trusted arbitrator for resolving copyright disputes and tracing illegal users, addressing the untrustworthy nature of traditional third-party approaches. Furthermore, blockchain ensures that copyrights stored on the chain cannot be tampered with and provides an open, transparent, and fully traceable transaction environment for data. In the event of copyright conflicts, the copyright and transaction information recorded on the blockchain can serve as evidence to avoid copyright disputes. To leverage these blockchain characteristics, most current blockchain-based copyright protection solutions rely on smart contracts to verify the authenticity and integrity of transaction data, enabling trusted transactions. They also extract and audit watermark information from pirated data to trace and punish infringers. However, these approaches fail to consider the open and transparent nature of blockchain, which can lead to the exposure of original data content and the confidentiality of watermarks when blockchain directly replaces third parties in performing watermarking operations. Secondly, on-chain computing and storage resources are extremely limited. Storing watermark information and transaction information on-chain, as well as performing watermark operations and traceability, results in significant computational and communication overhead for the system as a whole, reducing the efficiency of the entire blockchain system. Therefore, performing lightweight watermark verification and data integrity verification calculations on-chain in the ciphertext domain is a key and significant technical challenge in achieving secure, reliable, and traceable data security in an environment where both parties lack mutual trust. Summary of the Invention

[0004] This paper aims to propose a digital copyright protection method based on exchange cryptographic watermarks and blockchain. Combining orthogonal decomposition exchange cryptographic watermarking technology with blockchain technology, this method achieves copyright protection and secure, reliable control and traceability of data. A data control and traceability model based on exchange cryptographic watermarking and blockchain technology is studied. The blockchain acts as a trusted third party to perform watermark verification and traceability in the ciphertext domain. While ensuring data security, users who illegally distribute and use data can be traced and traced, achieving copyright protection, control and traceability of the data. Furthermore, the blockchain records the transaction process to ensure the traceability of the data distribution process. Based on this, a data copyright protection, control and traceability method based on orthogonal decomposition exchange cryptographic watermarks and blockchain is designed. An efficient and verifiable watermark verification and traceability algorithm suitable for blockchain environments is proposed to address the high cost of watermark verification and traceability tasks, which are computationally expensive for blockchain platforms. This solution integrates digital watermark technology, blockchain consensus technology and transaction mutual trust technology. It uses blockchain to replace third-party entities to safely and efficiently complete watermark verification and trusted traceability calculation tasks, and solves the problems of data ownership confirmation, traceability and mutual trust faced in scenarios where only data owners and users are non-trusting entities. It provides full-process security protection technology for data, creates a safe and trustworthy data circulation and transaction environment that can be confirmed, traced and secure, and provides technical support and innovative paths for data copyright protection and security.

[0005] The solution for this program is: Participants in this solution include data owners, users, and the blockchain. The data owner uses exchange cryptographic watermarking technology to embed a digital watermark in ciphertext, stores the watermark information in the blockchain, and sends the watermarked ciphertext data to the user, who decrypts and recovers the watermarked data. During this process, the blockchain records transaction information during the data distribution process, ensuring traceability. In the event of copyright disputes and tracing, the blockchain uses a lightweight watermark verification algorithm to extract the digital watermark from the ciphertext to confirm copyright ownership and track illegal users. Specifically, in the preprocessing phase, the data owner initializes the system and generates relevant keys. Subsequently, the data owner encrypts the data and embeds the copyright information using an exchange cryptographic watermarking technique with orthogonal decomposition, generating a ciphertext containing the copyright information. This ciphertext is then stored in the blockchain. During the data distribution phase, the user initiates a data request from the data owner. The data owner generates and embeds fingerprint information in the ciphertext using an exchange cryptographic watermarking technique with orthogonal decomposition, generating ciphertext containing the fingerprint. The data owner then constructs a Merkle tree based on the fingerprint information and writes the calculated Merkle root as the fingerprint commitment to the blockchain. Finally, the data owner sends the watermarked ciphertext data, the encryption operation matrix, and the decryption key to the user. The user uses the decryption key to recover the plaintext data with the fingerprint. During the piracy tracing phase, the data owner extracts the fingerprint from the pirated data and compares it with each user's original fingerprint to locate the suspected infringer. The extracted fingerprint is then uploaded to the blockchain, requesting the blockchain system to conduct traceability. The blockchain invokes the trusted traceability module to verify the validity of the uploaded fingerprint, calculate the similarity between the pirated data fingerprint and the uploaded embedded fingerprint, and compare it with a preset threshold. If the threshold is exceeded, the source of the data breach is determined by combining the fingerprint information and transaction records. This process enables secure data sharing and use.

[0006] The present invention provides a digital copyright protection method based on exchanging cryptographic watermarks and blockchain, comprising the following steps: In step S1, the data owner completes the initialization parameter setting and constructs the copyright information. The copyright information is embedded into the data using the exchange password watermark, and the copyright information and its copyright watermark domain information are stored on the chain.

[0007] In step S2, the user initiates a data request, the data owner verifies the user's fingerprint information, and uses the orthogonal decomposition exchange cryptographic watermarking technology to embed the fingerprint information in the fingerprint domain coefficients, and generates the watermarked ciphertext through orthogonal fusion.

[0008] In step S3, the data owner stores the fingerprint-related information and its watermark domain information on the chain, records the transaction information in the blockchain, and then transmits the ciphertext data containing the fingerprint, the decryption key, and the decryption-related orthogonal matrix to the user.

[0009] In step S4, when the data owner discovers a pirated copy, he or she extracts a fingerprint from the pirated data locally and calculates the correlation between the extracted fingerprint and the fingerprints of all transaction users. The fingerprint with the highest correlation is considered a suspected infringing fingerprint, and a traceability request is initiated to the blockchain, which then completes the threshold calculation.

[0010] In step S5, the data owner and the user use the interactive watermark challenge response process based on the smart contract to complete the trusted traceability, and use the blockchain to complete the watermark verification calculation and trusted traceability to resolve the dispute between the two parties on the correctness and validity of the uploaded fingerprint, thereby ensuring the rights and interests of both parties.

[0011] In step S6, if the tracked user does not initiate a challenge within the specified time limit, or the blockchain successfully verifies the validity of the uploaded watermark and its correlation with the original fingerprint exceeds the threshold, the smart contract will track and record the illegal distribution and use behavior of the infringing user based on the extracted fingerprint information and transaction records.

[0012] Furthermore, the specific implementation of step S1 is as follows: S11, parameter configuration: the copyright owner selects the encryption algorithm based on the data characteristics and the requirements of the exchange cipher watermark technology based on orthogonal decomposition Watermarking Algorithm , and generate a secret key , watermark key and orthogonal matrices ;in To encrypt the secret key, To decrypt the secret key, Embed the control key for the watermark, Extract the control key for the watermark, is the set of orthogonal basis vectors in the encryption domain, and is a set of orthogonal basis vectors in the watermark domain; S12, Copyright Generation: The data owner generates copyright information , which includes a hash of the data , data owner identity and information used to prove copyright ownership ; S13, Copyright Embedding: The data owner performs orthogonal decomposition on the original data to obtain the encrypted domain coefficients and watermark domain coefficients ( ), where the encryption domain coefficient Will be encrypted to protect the confidentiality of the carrier data, the watermark domain coefficient Will be used to embed copyright information, and the watermark domain coefficient Will be used to embed user fingerprints; in the watermark domain coefficients Embed copyright information , and the encrypted domain coefficients Encryption is performed; then the ciphertext data containing copyright information is obtained through orthogonal fusion ; S14, Copyright Notarization: The data owner uses the watermark operation matrix Each orthogonal basis vector of For leaf nodes, generate a Merkle tree , generate evidence information , and send it to the blockchain for storage. The message includes the identity of the data owner. , data hash value , copyright hash value , Merkle tree Root , used to verify the Merkle tree Auxiliary information , data transaction price and copyright description ; Merkle Tree The calculation formula is as follows: .

[0013] in is the Merkle tree generation algorithm, is the watermark matrix The orthogonal basis vectors of is the watermark matrix The number of orthogonal basis vectors in .

[0014] Furthermore, the calculation formulas for the orthogonal decomposition and orthogonal fusion processes are as follows: .

[0015] Furthermore, the specific implementation of step S2 is as follows: S21, request data: the user constructs fingerprint information according to actual application requirements , which includes the user identity Hash value of the requested data , and the hash value of the fingerprint information Save to the blockchain; then, the user requests the data sent to the data owner; S22, Fingerprint Embedding: The data owner compares and verifies the user's fingerprint information to ensure that the hash value of the fingerprint information matches the fingerprint hash value stored on the chain. If the verification fails, the request is rejected; if the verification passes, the watermark domain coefficient is embedded using the orthogonal decomposition exchange password watermarking technology. Embed fingerprint information And generate fingerprint ciphertext through orthogonal fusion. The fingerprint embedding calculation formula is as follows:

[0016] in is the encrypted domain coefficient, is the watermark domain coefficient that embeds copyright information, It is encrypted data containing copyright information.

[0017] Furthermore, in practical applications, fingerprints are repeatedly embedded in the orthogonal decomposition coefficients of the data:

[0018] in is the watermark domain coefficient that embeds copyright information, , and are all orthogonal basis vector sets in the fingerprint domain, used to repeatedly embed user fingerprints to enhance the robustness of the watermark. 、 and is the fingerprint embedding control key. The above formula shows that by controlling the division of the orthogonal matrix in the fingerprint domain, the user fingerprint can be repeatedly embedded in different orthogonal coefficient areas.

[0019] Furthermore, the specific implementation of step S3 is as follows: S31, fingerprint operation information storage: the data owner uses the copyright watermark operation matrix Each orthogonal basis vector of For leaf nodes, build a Merkle tree , the calculation process is as follows:

[0020] in is the Merkle tree generation algorithm, is the watermark matrix The orthogonal basis vectors of is the watermark matrix The number of orthogonal basis vectors in ; Data owner generates transaction information , and store evidence on the chain; transaction information includes user identity , fingerprint hash value 、Merkle tree root , construct a Merkle tree Auxiliary information , and transaction description ; The transaction information is described as follows:

[0021] S32, Transmit Ciphertext Data: The data owner encrypts the message Sent to user, key Can be transmitted through a secure channel, and the user uses the decryption key after receiving it Decryption can restore the plaintext data containing fingerprints .

[0022] Furthermore, the specific implementation of step S4 is as follows: S41, tracing request: After discovering pirated data, the data owner extracts fingerprints from the pirated data locally ; Then, the data owner calculates and extracts the fingerprint The correlation between all transaction user fingerprints related to the data and the fingerprint with the highest correlation The data owner then divides the pirated data into blocks and generates a Merkle tree with each block of data as a leaf node:

[0023] in For pirated data, yes Pirated data blocks after block processing, There is no overlap between them, is the number of blocks; Data owner constructs traceability request and send it to the blockchain for traceability; the request contains the suspected infringement fingerprint extracted by the data owner , the fingerprint with the highest correlation , Merkle tree Root and auxiliary information ; S42, threshold calculation: After receiving the traceability request, the blockchain first calculates the fingerprint The hash value is compared with the hash stored on the chain to ensure the evidence Correctness; Blockchain computation fingerprint and uploaded suspected infringing fingerprints If the correlation value exceeds the preset threshold, the smart contract will trigger an event and notify the tracked user to verify the validity of the uploaded fingerprint; otherwise, if it is lower than the correlation infringement judgment threshold, the tracing request will be terminated.

[0024] Furthermore, the specific implementation of step S5 is as follows: S51, verify data transmission: the data owner compares the pirated data with the fingerprint key ( )Send user; S52, challenge tracing results: the user locally based on the pirated data and the received watermark operation matrix , to determine the fingerprint information uploaded by the data owner to the smart contract First, the watermark operation matrix is ​​verified using the verifiable property of the Merkle tree. The correctness of the pirated data Perform orthogonal decomposition to obtain the watermark operation domain coefficients and extract the fingerprint from the watermark operation domain coefficients , by comparing the extracted fingerprints Fingerprint information uploaded to the smart contract by the data owner , locate the specific watermark dispute position, that is, obtain the fingerprint extracted by the user himself Fingerprint information uploaded to the smart contract by the data owner Different bit position indexes as challenge sets Send to smart contract for challenge; S53, respond and upload data: the data owner locally responds to the challenge set uploaded by the user Get the corresponding response data and send it to the smart contract to complete the verification; first, according to the challenge set The index in , using the Merkle tree search algorithm Get the corresponding challenge set The location index node hash and the hash value of the sibling node on its path, that is, the algorithm obtains the sibling node value in the Merkle verification path, and then compares it with the pirated data Composing a response collection Send to smart contract; S54, Verifying Infringement Data: A Collection of Smart Contract Computation and Comparison Challenges The index corresponds to the watermark bit value; first, through the Merkle tree verification algorithm Verify the response collection uploaded by the data owner The authenticity of the pirated data and orthogonal basis vectors in , if the verification fails, the response set is considered Invalid, the traceability ends; then, perform orthogonal decomposition and extract the disputed watermark bit, and compare it with the fingerprint information stored on the chain Compare the corresponding watermark bits. If they are equal, it means the fingerprint information uploaded by the data owner Is authentic and valid, otherwise, it indicates that the uploaded fingerprint information is suspected of infringement invalid.

[0025] Furthermore, the specific implementation of step S6 is as follows: If the tracked user does not initiate a challenge within the specified time limit, or the blockchain successfully verifies the validity of the uploaded watermark and its correlation with the original fingerprint exceeds the threshold, the smart contract will track and record the illegal distribution and use of the infringing user based on the extracted fingerprint information and transaction records. Otherwise, it does not constitute infringement.

[0026] The present invention also provides a digital copyright protection system based on exchange password watermarks and blockchain, comprising: A processor and a memory, the memory is used to store program instructions, and the processor is used to call the stored instructions in the memory to execute a digital copyright protection method based on exchange password watermarks and blockchain as described in the above technical solution.

[0027] Compared with other methods, the advantages of this invention are as follows: the digital copyright protection method based on exchanging cryptographic watermarks and blockchain proposed in this invention protects data security by exchanging cryptographic watermarks, allowing the blockchain to complete watermark verification calculations in the ciphertext domain. A Merkle tree-based evidence storage algorithm is proposed to complete the on-chain evidence storage of data, orthogonal matrices, fingerprint operation information, and transaction information, effectively reducing blockchain storage overhead and preventing both parties from falsifying data during data integrity verification and piracy traceability verification. Furthermore, an interactive trusted traceability algorithm is proposed to trace illegal distributors. This algorithm uses a watermark challenge-response protocol to narrow the scope of disputes in off-chain traceability calculation results, and the blockchain recalculates and verifies the results of the disputed scope, effectively reducing the computational overhead of verification calculations and achieving trusted traceability, thus realizing trusted traceability for data copyright security protection and illegal distribution behavior. This solution can complete trusted traceability tracking in two-party blockchain-based scenarios. It has the advantages of fewer participating entities, security and trustworthiness, low computing overhead and scalability. It breaks through the bottlenecks of data ownership confirmation, data traceability and mutual trust faced in the scenario where only the data owner and the user are non-trusting entities. It provides full-process security protection technology for data, creates a safe and trustworthy data circulation and transaction environment that can be confirmed, traced and secure, and provides technical support and innovative paths for data copyright protection and security. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a general schematic diagram of the digital copyright protection method according to an embodiment of the present invention.

[0029] Figure 2 This is a specific processing flow chart of Merkle information notarization according to an embodiment of the present invention.

[0030] Figure 3 This is a specific processing flow chart of the blockchain-based interactive trusted traceability process in an embodiment of the present invention.

[0031] Figure 4This is a specific processing flow chart of the smart contract verification response process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is described in detail below with reference to the accompanying drawings.

[0033] The embodiment of the present invention provides a digital copyright protection method based on exchange password watermark and blockchain, combined with the attached Figure 1 , 2, 3, 4 describe the implementation steps of the present invention in detail: Step S1: The data owner completes the initialization parameter settings and constructs the copyright information. The copyright information is embedded into the data using the exchange password watermark, and the copyright information and its copyright watermark operation domain information are stored on the chain. Step S2: The user initiates a data request, the data owner verifies the user's fingerprint information, and uses the orthogonal decomposition exchange cryptographic watermarking technology to embed the fingerprint information in the fingerprint domain coefficients, and generates the watermarked ciphertext through orthogonal fusion; Step S3: The data owner stores the fingerprint-related information and its watermark operation domain information on the blockchain, records the transaction information in the blockchain, and then transmits the ciphertext data containing the fingerprint, the decryption key, and the decryption-related orthogonal matrix to the user; Step S4: When the data owner discovers a pirated copy, they extract a fingerprint from the pirated data locally and calculate the correlation between the extracted fingerprint and the fingerprints of all transaction users. The fingerprint with the highest correlation is considered a suspected infringing fingerprint, and a traceability request is initiated to the blockchain, which then completes the threshold calculation. Step S5: The data owner and the user complete the trusted traceability through the interactive watermark challenge response process based on the smart contract, and use the blockchain to complete the watermark verification calculation and trusted traceability; In step S6, if the tracked user does not initiate a challenge within the specified time limit, or the blockchain successfully verifies the validity of the uploaded watermark and its correlation with the original fingerprint exceeds the threshold, the smart contract will track and record the illegal distribution and use behavior of the infringing user based on the extracted fingerprint information and transaction records.

[0034] The preprocessing process is as follows: Step 1a: Parameter configuration: The copyright owner selects a suitable encryption algorithm based on the data characteristics and the requirements of the exchange cipher watermark technology based on orthogonal decomposition. Watermarking Algorithm , such as using the symmetric encryption AES algorithm and the quantized index modulation watermark algorithm, and generating a secret key , watermark key ,in To encrypt the secret key, To decrypt the secret key, Embed the control key for the watermark, Extract the control key for the watermark, and the orthogonal matrix ,in is the set of orthogonal basis vectors in the encryption domain, and is a set of orthogonal basis vectors in the watermark domain.

[0035] Step 1b: Copyright generation: Data owner generates copyright information , which includes a hash of the data , data owner identity and information used to prove copyright ownership .

[0036] Step 1c: Copyright embedding: The data owner performs orthogonal decomposition on the original data to obtain the encrypted domain coefficients and watermark domain coefficients ( ), where the encryption domain coefficient Will be encrypted to protect the confidentiality of the carrier data, the watermark domain coefficient Will be used to embed copyright information, and the watermark domain coefficient Will be used to embed the user's fingerprint. In the watermark domain coefficient Embed copyright information , and the encrypted domain coefficients Encryption is performed; then the ciphertext data containing copyright information is obtained through orthogonal fusion This process can spread the encryption effect of part of the data to the entire data, thereby achieving privacy protection of the entire data. The calculation formula of the orthogonal decomposition and orthogonal fusion process is as follows:

[0037] Step 1d: Copyright notarization: The data owner uses a watermark matrix Each orthogonal basis vector of Generate a Merkle tree for the leaf nodes , generate evidence information , and send it to the blockchain for storage. The message includes the identity of the data owner , data hash value , copyright hash value , Merkle Tree Root , used to verify the Merkle tree Auxiliary information , data transaction price and copyright description The timestamp of the message on the blockchain can be used to determine the embedding order of copyright watermarks, thereby effectively resolving copyright ownership disputes. The calculation formula is as follows, where is the Merkle tree generation algorithm, is the watermark matrix The orthogonal basis vectors of is the watermark matrix The number of orthogonal basis vectors in .

[0038]

[0039] The fingerprint construction and embedding process is as follows: Step 2a: Request data: The user constructs fingerprint information based on actual application requirements , which includes the user identity Hash value of the requested data , and the hash value of the fingerprint information Save to the blockchain. Later, the user will request the data Sent to the data owner.

[0040] Step 2b: Fingerprint embedding: The data owner compares and verifies the user's fingerprint information to ensure that the hash value of the fingerprint information matches the fingerprint hash value stored on the chain. If the verification fails, the request is rejected. If the verification passes, the watermark domain coefficients are embedded using the orthogonal decomposition exchange password watermarking technology. Embed fingerprint information And generate fingerprint ciphertext through orthogonal fusion. The fingerprint embedding calculation formula is as follows:

[0041] in is the encrypted domain coefficient, is the watermark domain coefficient that embeds copyright information, It is the encrypted data containing copyright information. It is worth noting that in practical applications, the fingerprint will be repeatedly embedded in the orthogonal decomposition coefficients of the data to enhance the robustness of the watermark and the accuracy of the extraction process.

[0042]

[0043] in is the watermark domain coefficient that embeds copyright information, , and are all orthogonal basis vector sets in the fingerprint domain, used to repeatedly embed user fingerprints to enhance the robustness of the watermark. 、 and is the fingerprint embedding control key. The above formula shows that by controlling the division of the orthogonal matrix in the fingerprint domain, the user fingerprint can be repeatedly embedded in different orthogonal coefficient areas.

[0044] The process of storing transaction information and fingerprint operation information on the chain and distributing data is as follows: Step 3a: Fingerprint operation information storage: the data owner uses the copyright watermark operation matrix Each orthogonal basis vector of For leaf nodes, build a Merkle tree , the calculation process is as follows:

[0045] in is the Merkle tree generation algorithm, is the watermark matrix The orthogonal basis vectors of is the watermark matrix The number of orthogonal basis vectors in .

[0046] Data owner generates transaction information , and store the evidence on the chain. Transaction information includes user identity , fingerprint hash value 、Merkle tree root , construct a Merkle tree Auxiliary information , and transaction description The transaction information is described as follows:

[0047] Step 3b: Transmitting ciphertext data: The data owner will encrypt the message Sent to user, key Can be transmitted through a secure channel, and the user uses the decryption key after receiving it Decryption can restore the plaintext data containing fingerprints .

[0048] The traceability request process is as follows: Step 4a: Origin Request: After discovering pirated data, the data owner extracts fingerprints from the pirated data locally Next, the data owner calculates the extracted fingerprint The correlation between all transaction user fingerprints related to the data and the fingerprint with the highest correlation The data owner then divides the pirated data into blocks and generates a Merkle tree with each block of data as a leaf node:

[0049] in For pirated data, yes Pirated data blocks after block processing, There is no overlap between them, is the number of blocks.

[0050] Data owner constructs traceability request The request contains the suspected infringement fingerprint extracted by the data owner. , the fingerprint with the highest correlation , Merkle tree Root and auxiliary information .

[0051] Step 4b: Threshold calculation: After receiving the traceability request, the blockchain first calculates the fingerprint The hash value is compared with the hash stored on the chain to ensure the evidence The correctness of blockchain computing fingerprint. and uploaded suspected infringing fingerprints If the correlation value exceeds the preset threshold, the smart contract will trigger an event and notify the tracked user to verify the validity of the uploaded fingerprint; otherwise, if it is lower than the relevance infringement determination threshold, the tracing request will be terminated.

[0052] The interactive trusted traceability process is as follows: Step 5a: Verify data transmission: As direct stakeholders, both parties may have some malicious behaviors to forge or deny the traceability process in a two-party scenario based on blockchain, resulting in ambiguity and invalidation of the traceability results. Both parties need to use blockchain to complete watermark verification calculation to resolve disputes and protect the rights and interests of both parties. Therefore, the data owner will use the pirated data and the fingerprint key ( )Send user.

[0053] It is worth noting that even if the data owner does not transmit or transmits pirated data and fingerprint keys ( ), users can still continue to randomly challenge to verify the correctness of the uploaded fingerprint.

[0054] Step 5b: Challenge the traceability result: The user can locally and the received watermark operation matrix , to determine the fingerprint information uploaded by the data owner to the smart contract First, the watermark operation matrix is ​​verified using the verifiable property of the Merkle tree. Then the pirated data Perform orthogonal decomposition to obtain watermark domain coefficients and extract fingerprints from watermark domain coefficients , by comparing the extracted fingerprints and fingerprint information uploaded to the smart contract by the data owner , locate the specific watermark dispute position, that is, obtain the fingerprint extracted by the user himself Fingerprint information uploaded to the smart contract by the data owner Different bit position indexes as challenge sets Send to the smart contract for challenge. It is worth noting that even if the data owner does not transmit or transmits tampered pirated data and fingerprint keys ( ) to the user, the user can still perform random challenges (random location indexes) to allow the blockchain to verify the correctness of the uploaded fingerprint.

[0055] Step 5c: Respond and upload data: The data owner locally responds to the challenge set uploaded by the user. Get the corresponding response data and send it to the smart contract to complete the verification. First, according to the challenge set The index in , using the Merkle tree search algorithm , you can get the target node hash and its sibling node hashes on the path, and apply this algorithm to get the corresponding challenge set The hash value of the location index node and its sibling node hash value on the path, that is, the algorithm obtains the sibling node value in the Merkle verification path. Then, the pirated data Composing a response collection Send to the smart contract.

[0056] Step 5d: Verify infringement data: Smart contract calculation and comparison challenge set The index corresponds to the watermark bit value. First, the Merkle tree verification algorithm is used , reconstruct the root hash through hash calculation and compare it with the Merkle root hash Merkle Root stored on the chain. If they are consistent, it proves that the target node exists. ‌‌ Apply this algorithm to verify the response set uploaded by the data owner The authenticity of the pirated data and orthogonal basis vectors in , if the verification fails, the response set is considered Invalid, the traceability ends. Then, perform orthogonal decomposition and extract the disputed watermark bit, and compare it with the fingerprint information stored on the chain. Compare the corresponding watermark bits. If they are equal, it means the fingerprint information uploaded by the data owner Is authentic and valid, otherwise, it indicates that the uploaded fingerprint information is suspected of infringement invalid.

[0057] The process of determining the traceability results is as follows: Step 6a: Trusted traceability: If the tracked user does not initiate a challenge within the specified time limit, or the blockchain successfully verifies the validity of the uploaded watermark and its correlation with the original fingerprint exceeds the threshold, the smart contract will track and record the illegal distribution and use of the infringing user based on the extracted fingerprint information and transaction records. Otherwise, no infringement is constituted.

[0058] In summary, this paper proposes a digital copyright protection method based on exchange cryptographic watermarking and blockchain technology. First, the exchangeability of exchange cryptographic watermarking technology enables digital watermark embedding and extraction in encrypted form to prevent data leakage. A Merkle tree structure is then used to store data and watermark (fingerprint) domain information on the blockchain for data integrity verification and distribution traceability, preventing data forgery and reducing blockchain storage overhead. The blockchain records data distribution information and watermark information throughout the entire process, ensuring the transparency of the traceability process. While protecting data security, users who illegally distribute or use data can be traced. The proposed solution provides a robust, low-entity, secure, reliable, low-computational-cost, and scalable solution for digital copyright protection. It provides end-to-end data security protection technology, creating a secure and trustworthy data circulation and transaction environment with verifiable ownership, traceability, and security. This approach can be widely applied in digital copyright protection, trusted data transaction and circulation, and data security control and traceability, promoting secure data sharing and application.

[0059] On the other hand, an embodiment of the present invention further provides a digital copyright protection system based on exchanged cryptographic watermarks and blockchain, comprising: A processor and a memory, the memory is used to store program instructions, and the processor is used to call the stored instructions in the memory to execute a digital copyright protection method based on exchange password watermarks and blockchain as described in the above technical solution.

[0060] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A digital copyright protection method based on exchange password watermark and blockchain, characterized in that: The steps include: Step S1: The data owner completes the initialization parameter settings and constructs the copyright information. The copyright information is embedded into the data using the exchange password watermark, and the copyright information and its copyright watermark operation domain information are stored on the chain. Step S2: The user initiates a data request, the data owner verifies the user's fingerprint information, and uses the orthogonal decomposition exchange cryptographic watermarking technology to embed the fingerprint information in the fingerprint domain coefficients, and generates the watermarked ciphertext through orthogonal fusion; In step S3, the data owner stores the fingerprint-related information and its watermark operation domain information on the blockchain, records the transaction information in the blockchain, and then transmits the ciphertext data containing the fingerprint, the decryption key, and the decryption-related orthogonal matrix to the user; Step S4: When the data owner discovers a pirated copy, they extract a fingerprint from the pirated data locally and calculate the correlation between the extracted fingerprint and the fingerprints of all transaction users. The fingerprint with the highest correlation is considered a suspected infringing fingerprint, and a traceability request is initiated to the blockchain, which then completes the threshold calculation. Step S5: The data owner and the user complete the trusted traceability through the interactive watermark challenge response process based on the smart contract, and use the blockchain to complete the watermark verification calculation and trusted traceability; Step S6: Determine the traceability result.

2. The digital copyright protection method based on exchanging password watermarks and blockchain as claimed in claim 1, characterized in that: The specific implementation of step S1 is as follows: S11, parameter configuration: the copyright owner selects the encryption algorithm based on the data characteristics and the requirements of the exchange cipher watermark technology based on orthogonal decomposition Watermarking Algorithm , and generate a secret key , watermark key and orthogonal matrices ;in To encrypt the secret key, To decrypt the secret key, Embed the control key for the watermark, Extract the control key for the watermark, is the set of orthogonal basis vectors in the encryption domain, and is a set of orthogonal basis vectors in the watermark domain; S12, Copyright Generation: The data owner generates copyright information , which includes a hash of the data , data owner identity and information used to prove copyright ownership ; S13, Copyright Embedding: The data owner performs orthogonal decomposition on the original data to obtain the encrypted domain coefficients and watermark domain coefficients ( ), where the encryption domain coefficient Will be encrypted to protect the confidentiality of the carrier data, the watermark domain coefficient Will be used to embed copyright information, and the watermark domain coefficient Will be used to embed user fingerprints; in the watermark domain coefficients Embed copyright information , and the encrypted domain coefficients Encryption is performed; then the ciphertext data containing copyright information is obtained through orthogonal fusion ; S14, Copyright Notarization: The data owner uses the watermark operation matrix Each orthogonal basis vector of For leaf nodes, generate a Merkle tree , generate evidence information , and send it to the blockchain for storage. The message includes the identity of the data owner. , data hash value , copyright hash value , Merkle tree Root , used to verify the Merkle tree Auxiliary information , data transaction price and copyright description ; Merkle Tree The calculation formula is as follows: 。 in is the Merkle tree generation algorithm, is the watermark matrix The orthogonal basis vectors of is the watermark matrix The number of orthogonal basis vectors in .

3. A digital copyright protection method based on exchanging password watermarks and blockchain as described in claim 2, characterized in that: The calculation formulas for orthogonal decomposition and orthogonal fusion processes are as follows: 。 4. The digital copyright protection method based on exchanging password watermarks and blockchain as claimed in claim 1, characterized in that: The specific implementation of step S2 is as follows: S21, request data: the user constructs fingerprint information according to actual application requirements , which includes the user identity Hash value of the requested data , and the hash value of the fingerprint information Save to blockchain; The user then requests the data sent to the data owner; S22, Fingerprint Embedding: The data owner compares and verifies the user's fingerprint information to ensure that the hash value of the fingerprint information matches the fingerprint hash value stored on the chain. If the verification fails, the request is rejected; if the verification passes, the watermark domain coefficient is embedded using the orthogonal decomposition exchange password watermarking technology. Embed fingerprint information And generate fingerprint ciphertext through orthogonal fusion. The fingerprint embedding calculation formula is as follows: in is the encrypted domain coefficient, is the watermark domain coefficient that embeds copyright information, It is encrypted data containing copyright information.

5. A digital copyright protection method based on exchanging password watermarks and blockchain as claimed in claim 4, characterized in that: In practical applications, fingerprints are repeatedly embedded in the orthogonal decomposition coefficients of the data: in is the watermark domain coefficient that embeds copyright information, , and are all orthogonal basis vector sets in the fingerprint domain, used to repeatedly embed user fingerprints to enhance the robustness of the watermark. 、 and is the fingerprint embedding control key. The above formula shows that by controlling the division of the orthogonal matrix in the fingerprint domain, the user fingerprint can be repeatedly embedded in different orthogonal coefficient areas.

6. The digital copyright protection method based on exchanging password watermarks and blockchain as claimed in claim 1, characterized in that: The specific implementation of step S3 is as follows: S31, fingerprint operation information storage: the data owner uses the copyright watermark operation matrix Each orthogonal basis vector of For leaf nodes, build a Merkle tree , the calculation process is as follows: in is the Merkle tree generation algorithm, is the watermark matrix The orthogonal basis vectors of is the watermark matrix The number of orthogonal basis vectors in ; Data owner generates transaction information , and store evidence on the chain; transaction information includes user identity , fingerprint hash value 、Merkle tree root , construct a Merkle tree Auxiliary information , and transaction description ; The transaction information is described as follows: S32, Transmit Ciphertext Data: The data owner encrypts the message Sent to user, key Can be transmitted through a secure channel, and the user uses the decryption key after receiving it Decryption can restore the plaintext data containing fingerprints .

7. The digital copyright protection method based on exchanging password watermarks and blockchain as claimed in claim 1, characterized in that: The specific implementation of step S4 is as follows: S41, tracing request: After discovering pirated data, the data owner extracts fingerprints from the pirated data locally ; Then, the data owner calculates and extracts the fingerprint The correlation between all transaction user fingerprints related to the data and the fingerprint with the highest correlation The data owner then divides the pirated data into blocks and generates a Merkle tree with each block of data as a leaf node: in For pirated data, yes Pirated data blocks after block processing, There is no overlap between them, is the number of blocks; Data owner constructs traceability request and send it to the blockchain for traceability; the request contains the suspected infringement fingerprint extracted by the data owner , the fingerprint with the highest correlation , Merkle tree Root and auxiliary information ; S42, threshold calculation: After receiving the traceability request, the blockchain first calculates the fingerprint The hash value is compared with the hash stored on the chain to ensure the evidence Correctness; Blockchain computation fingerprint and uploaded suspected infringing fingerprints If the correlation value exceeds the preset threshold, the smart contract will trigger an event and notify the tracked user to verify the validity of the uploaded fingerprint; otherwise, if it is lower than the correlation infringement judgment threshold, the tracing request will be terminated.

8. The digital copyright protection method based on exchanging password watermarks and blockchain as claimed in claim 1, characterized in that: The specific implementation of step S5 is as follows: S51, verify data transmission: the data owner compares the pirated data with the fingerprint key ( )Send user; S52, challenge tracing results: the user locally based on the pirated data and the received watermark operation matrix , to determine the fingerprint information uploaded by the data owner to the smart contract First, the watermark operation matrix is ​​verified using the verifiable property of the Merkle tree. The correctness of the pirated data Perform orthogonal decomposition to obtain the watermark operation domain coefficients and extract the fingerprint from the watermark operation domain coefficients , by comparing the extracted fingerprints Fingerprint information uploaded to the smart contract by the data owner , locate the specific watermark dispute position, that is, obtain the fingerprint extracted by the user himself Fingerprint information uploaded to the smart contract by the data owner Different bit position indexes as challenge sets Send to smart contract for challenge; S53, respond and upload data: the data owner locally responds to the challenge set uploaded by the user Get the corresponding response data and send it to the smart contract to complete the verification; first, according to the challenge set The index in , using the Merkle tree search algorithm Get the corresponding challenge set The location index node hash and the hash value of the sibling node on its path, that is, the algorithm obtains the sibling node value in the Merkle verification path, and then compares it with the pirated data Composing a response collection Send to smart contract; S54, Verifying Infringement Data: A Collection of Smart Contract Computation and Comparison Challenges The index corresponds to the watermark bit value; first, through the Merkle tree verification algorithm Verify the response collection uploaded by the data owner The authenticity of the pirated data and orthogonal basis vectors in , if the verification fails, the response set is considered Invalid, the traceability ends; then, perform orthogonal decomposition and extract the disputed watermark bit, and compare it with the fingerprint information stored on the chain Compare the corresponding watermark bits. If they are equal, it means the fingerprint information uploaded by the data owner Is authentic and valid, otherwise, it indicates that the uploaded fingerprint information is suspected of infringement invalid.

9. The digital copyright protection method based on exchanging password watermarks and blockchain as claimed in claim 1, characterized in that: The specific implementation of step S6 is as follows: If the tracked user does not initiate a challenge within the specified time limit, or the blockchain successfully verifies the validity of the uploaded watermark and its correlation with the original fingerprint exceeds the threshold, the smart contract will track and record the illegal distribution and use of the infringing user based on the extracted fingerprint information and transaction records. Otherwise, it does not constitute infringement.

10. A digital copyright protection system based on exchange password watermark and blockchain, characterized in that: include: A processor and a memory, the memory being used to store program instructions, and the processor being used to call the stored instructions in the memory to execute a digital copyright protection method based on exchange password watermarks and blockchain as described in any one of claims 1 to 9.

Images