A data authorization sharing method based on blockchain and multi-party secure computing

Abstract

The present invention discloses a data authorization sharing method based on blockchain and multi-party secure computing, comprising the following steps: S1, system initialization; S2, data providers use Paillier homomorphic encryption algorithm to generate encrypted transaction data, and divide it into several shares through Shamir secret sharing scheme; S3, nodes participating in data authorization sharing receive the shares of encrypted transactions, store them locally, perform distributed computing according to optimized GMW protocol, and send the intermediate results of the calculation to the designated merging node through an encrypted channel; S4, after the merging node receives all the intermediate results, it merges the intermediate results through the optimized GMW protocol to obtain the final consensus result; S5, the merging node generates a new block, and broadcasts the new block to the whole network; S6, the transaction in the new block triggers the execution of the smart contract, and the execution result is recorded in the blockchain. The present invention combines blockchain and multi-party secure computing to realize data security sharing and improve computing efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of data security and privacy protection, and in particular to a data authorization sharing method based on blockchain and multi-party secure computing. Background Art

[0002] In the modern information society, data has become an important production factor and strategic resource. With the development of big data technology, the demand for data sharing in various fields is increasing, including finance, medical care, the Internet of Things and other fields. Data sharing can promote resource integration, improve service levels, and promote innovative development. However, data sharing also faces many challenges, especially in terms of privacy protection and data security. Traditional data sharing mainly includes centralized data sharing, data encryption transmission, access control and permission management, and multi-party secure computing. Although existing technical methods have solved the security and privacy issues in the data sharing process to a certain extent, there are still many defects and challenges, which are specifically manifested in the following aspects:

[0003] The first is insufficient privacy protection. The centralized data sharing model easily leads to data leakage and privacy infringement. Even with the use of encryption technology, the privacy protection of data during use and calculation is still insufficient. Existing encryption methods are mainly aimed at the security of data transmission, and have limited privacy protection during data storage and use.

[0004] The second is that security is difficult to guarantee. The centralized data storage and management model has the risk of single point failure and is vulnerable to hacker attacks and data leakage. In addition, the complex permission management system is prone to the risk of permission abuse and leakage, making it difficult to ensure the absolute security of data.

[0005] The third is low computational efficiency. Although multi-party secure computing can ensure data privacy, it has high computational complexity and high communication overhead, making it difficult to meet the needs of large-scale data sharing and computing. Existing MPC protocols have the problem of low computational efficiency in practical applications and cannot meet the requirements of efficient computing in the big data era.

[0006] Fourth, there is a lack of a trust mechanism. Traditional data sharing methods lack an effective trust mechanism, making it difficult to ensure the transparency and credibility of data transactions and sharing processes. The establishment of trust between data providers and users relies on third-party intermediaries, which poses potential trust and moral risks.

[0007] Therefore, how to provide a data authorization sharing method based on blockchain and multi-party secure computing is an urgent problem that technicians in this field need to solve. Summary of the invention

[0008] One purpose of the present invention is to propose a data authorization sharing method based on blockchain and multi-party secure computing. The present invention combines blockchain and multi-party secure computing to provide a safe, reliable and efficient data authorization sharing method, which effectively solves the problems of insufficient privacy protection, difficult security guarantee, low computing efficiency and lack of trusted mechanism in the prior art, and has significant technical advantages and practical application value.

[0009] A data authorization sharing method based on blockchain and multi-party secure computing according to an embodiment of the present invention includes the following steps:

[0010] S1. Initialize the system. Nodes participating in data authorization sharing obtain identity authentication through registration and generate public and private key pairs for multi-party secure computing.

[0011] S2. The data provider encrypts the transaction data using the Paillier homomorphic encryption algorithm to generate encrypted transaction data, and divides the encrypted transaction data into several shares using the Shamir secret sharing scheme;

[0012] S3. The node participating in the data authorization sharing receives the share of the encrypted transaction and stores it locally, performs distributed computing according to the optimized GMW protocol, and sends the intermediate results of the computing to the designated merging node through an encrypted channel;

[0013] S4. After receiving all the intermediate results, the merging node merges the intermediate results through the optimized GMW protocol to obtain the final consensus result;

[0014] S5. After the consensus result is confirmed to be correct, the merged node generates a new block and broadcasts the new block to the entire network;

[0015] S6. The transaction in the new block triggers the execution of the smart contract, which automatically runs in the blockchain network, executes predefined logic, and records the execution results in the blockchain.

[0016] Furthermore, the system initialization settings include Shamir secret sharing scheme parameters, Paillier homomorphic encryption parameters, and multi-party computing protocol configuration of the optimized GMW protocol;

[0017] The Shamir secret sharing scheme parameters include the number of split shares N and the minimum number of shares K required to recover data, and satisfy 1≤K≤N;

[0018] The Paillier homomorphic encryption parameters include two large prime numbers p and q;

[0019] The multi-party computing protocol configuration of the optimized GMW protocol includes the communication port and IP address of each node, and the random number generator seed required in each round of calculation.

[0020] Furthermore, the S2 specifically includes:

[0021] S21, the data provider selects transaction data D and pre-processes D;

[0022] S22. The data provider encrypts the transaction data D using the Paillier homomorphic encryption algorithm to generate encrypted transaction data E(D); the Paillier homomorphic encryption algorithm includes:

[0023] Select two large prime numbers p and q, and calculate the modulus n = p·q;

[0024] Calculate λ=lcm(p-1,q-1), where lcm represents the least common multiple;

[0025] Pick a random number Let the order of g be n;

[0026] Pick a random number

[0027] Calculate the encrypted data E(D):

[0028] E(D)=(g m ·r n )modn 2 ;

[0029] Where m is the plaintext representation of the transaction data D, g and r are the parameters required for encryption, and E(D) represents the result of homomorphic encryption;

[0030] S23. The data provider divides the encrypted transaction data E(D) into several shares according to the Shamir secret sharing scheme, including:

[0031] Choose a large prime number w as the modulus;

[0032] Choose a polynomial f(x) of degree t-1, where t is the minimum number of shares required to recover the secret and f(0) = E(D);

[0033] Calculate each share S i , the formula is:

[0034] S i =f(i)modp(i=1,2,…,n);

[0035] Where, f(x) = a0+a1x+a2x 2 +…+at-1 x t-1 , a0=E(D), a1, a2, …, a t-1 is a randomly selected coefficient, i represents a unique identifier assigned to a node;

[0036] S24, each share S i Securely distributed to each node participating in data authorization sharing.

[0037] Furthermore, the optimized GMW protocol specifically includes:

[0038] Set the number of protocol calculation rounds N;

[0039] Each node uses secret-sharing shares and homomorphically encrypted data to perform local calculations according to the optimized GMW protocol. Multiple rounds of communication and data exchange are required during the calculation process to ensure the consistency and correctness of the calculation results.

[0040] In each round of calculation, each node sends the intermediate results of the calculation to other nodes through an encrypted channel. After receiving the intermediate results sent by other nodes, each node performs further calculations and repeats this process until the number of protocol calculation rounds N is reached;

[0041] During the calculation process, each node compresses the communication data according to the preset optimization scheme to reduce the communication overhead, and uses the encryption algorithm based on Paillier homomorphic encryption to encrypt the intermediate results to ensure the security of the data during transmission;

[0042] After calculating the protocol calculation rounds N times, each node sends the final intermediate result to the designated merging node through an encrypted channel. The merging node is responsible for summarizing the intermediate results of all nodes.

[0043] Furthermore, the S4 specifically includes:

[0044] S41, aggregate the intermediate results sent by each node, expressed as:

[0045] R={r1,r2,…,r n}

[0046] Among them, r i Represents the intermediate result of the i-th node;

[0047] S42. Apply the characteristics of homomorphic encryption to perform weighted sum calculation on the intermediate results. The combined result C is expressed as:

[0048]

[0049] Among them, E(x) represents the homomorphic encryption of x, w irepresents the pre-set weight coefficient, g represents the common base number, t i represents the random number generated for the i-th node, the w i satisfy

[0050] S43, the merging node decrypts the merging result C, using the private key sk of the merging node merge Perform homomorphic decryption operations to obtain the final plaintext consensus result M;

[0051] S44, performing data verification on the plaintext consensus result M, wherein the data verification includes recalculating the hash value H(M) of M and comparing it with the hash value before decryption. If they are consistent, the result is considered correct;

[0052] S45. Record the final plaintext consensus result M in the local storage of the merging stage, and generate a transaction hash value H(M) for the generation and verification of the new block.

[0053] Furthermore, the predefined logic of the smart contract includes data access permission management and data sharing rules.

[0054] The beneficial effects of the present invention are:

[0055] (1) Improve the level of data privacy protection: The Paillier homomorphic encryption algorithm is used to encrypt transaction data, and the Shamir secret sharing scheme is used to split the encrypted data to ensure the privacy of data during sharing and calculation. The application of the multi-party secure computing (MPC) protocol enables each node to jointly participate in calculation and verification without leaking private data, further protecting data privacy.

[0056] (2) Enhanced data security: Blockchain technology is used to build a distributed ledger, and each node saves a complete copy of the ledger. Once the data is recorded, it cannot be tampered with. The decentralized architecture avoids the risk of single point failure and data leakage. At the same time, smart contracts automatically execute data authorization and sharing rules to ensure the security and credibility of data operations.

[0057] (3) Improve computing and consensus efficiency: Through the optimized GMW protocol, efficient distributed computing and consensus processes are achieved. In the process of calculating intermediate results, each node uses communication data compression and encryption technology, which significantly reduces communication overhead, improves computing efficiency, and meets the needs of large-scale data sharing and computing.

[0058] (4) Ensure the transparency and traceability of data sharing: By utilizing the transparency and traceability of blockchain, each data sharing and calculation process is recorded on the chain, and all operations are traceable. After a new block is generated, it is broadcast to the entire network to ensure that all nodes can synchronize the latest data, thereby enhancing the transparency and credibility of data sharing. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0060] Figure 1 A flowchart of a data authorization sharing method based on blockchain and multi-party secure computing proposed by the present invention;

[0061] Figure 2 This is a flowchart of data submission and segmentation for a data authorization sharing method based on blockchain and multi-party secure computing proposed by the present invention. DETAILED DESCRIPTION

[0062] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0063] refer to Figure 1 and Figure 2 , a data authorization sharing method based on blockchain and multi-party secure computing, comprising the following steps:

[0064] S1. Initialize the system. Nodes participating in data authorization sharing obtain identity authentication through registration and generate public and private key pairs for multi-party secure computing.

[0065] S2. The data provider encrypts the transaction data using the Paillier homomorphic encryption algorithm to generate encrypted transaction data, and divides the encrypted transaction data into several shares using the Shamir secret sharing scheme;

[0066] S3. The node participating in the data authorization sharing receives the share of the encrypted transaction and stores it locally, performs distributed computing according to the optimized GMW protocol, and sends the intermediate results of the computing to the designated merging node through an encrypted channel;

[0067] S4. After receiving all the intermediate results, the merging node merges the intermediate results through the optimized GMW protocol to obtain the final consensus result;

[0068] S5. After the consensus result is confirmed to be correct, the merged node generates a new block and broadcasts the new block to the entire network;

[0069] S6. The transaction in the new block triggers the execution of the smart contract, which automatically runs in the blockchain network, executes predefined logic, and records the execution results in the blockchain.

[0070] In this embodiment, the system initialization settings include Shamir secret sharing scheme parameters, Paillier homomorphic encryption parameters, and multi-party computing protocol configuration of the optimized GMW protocol;

[0071] The Shamir secret sharing scheme parameters include the number of split shares N and the minimum number of shares K required to recover data, and satisfy 1≤K≤N;

[0072] The Paillier homomorphic encryption parameters include two large prime numbers p and q;

[0073] The multi-party computing protocol configuration of the optimized GMW protocol includes the communication port and IP address of each node, and the random number generator seed required in each round of calculation.

[0074] In this implementation, S2 specifically includes:

[0075] S21, the data provider selects transaction data D and pre-processes D;

[0076] S22. The data provider encrypts the transaction data D using the Paillier homomorphic encryption algorithm to generate encrypted transaction data E(D); the Paillier homomorphic encryption algorithm includes:

[0077] Select two large prime numbers p and q, and calculate the modulus n = p·q;

[0078] Calculate λ=lcm(p-1,q-1), where lcm represents the least common multiple;

[0079] Pick a random number Let the order of g be n;

[0080] Pick a random number

[0081] Calculate the encrypted data E(D):

[0082] E(D)=(g m ·r n )modn 2 ;

[0083] Where m is the plaintext representation of the transaction data D, g and r are the parameters required for encryption, and E(D) represents the result of homomorphic encryption;

[0084] S23. The data provider divides the encrypted transaction data E(D) into several shares according to the Shamir secret sharing scheme, including:

[0085] Choose a large prime number w as the modulus;

[0086] Choose a polynomial f(x) of degree t-1, where t is the minimum number of shares required to recover the secret and f(0) = E(D);

[0087] Calculate each share S i , the formula is:

[0088] S i =f(i)modp(i=1,2,…,n);

[0089] Where, f(x) = a0+a1x+a2x 2 +…+a t-1 x t-1 , a0=E(D), a1, a2, …, a t-1 is a randomly selected coefficient, i represents a unique identifier assigned to a node;

[0090] S24, each share S i Securely distributed to each node participating in data authorization sharing.

[0091] In this implementation, the optimized GMW protocol specifically includes:

[0092] Set the number of protocol calculation rounds N;

[0093] Each node uses secret-sharing shares and homomorphically encrypted data to perform local calculations according to the optimized GMW protocol. Multiple rounds of communication and data exchange are required during the calculation process to ensure the consistency and correctness of the calculation results.

[0094] In each round of calculation, each node sends the intermediate results of the calculation to other nodes through an encrypted channel. After receiving the intermediate results sent by other nodes, each node performs further calculations and repeats this process until the number of protocol calculation rounds N is reached;

[0095] During the calculation process, each node compresses the communication data according to the preset optimization scheme to reduce the communication overhead, and uses the encryption algorithm based on Paillier homomorphic encryption to encrypt the intermediate results to ensure the security of the data during transmission;

[0096] After calculating the protocol calculation rounds N times, each node sends the final intermediate result to the designated merging node through an encrypted channel. The merging node is responsible for summarizing the intermediate results of all nodes.

[0097] In this implementation manner, the S4 specifically includes:

[0098] S41, aggregate the intermediate results sent by each node, expressed as:

[0099] R={r1,r2,…,r n}

[0100] Among them, r i Represents the intermediate result of the i-th node;

[0101] S42. Apply the characteristics of homomorphic encryption to perform weighted sum calculation on the intermediate results. The combined result C is expressed as:

[0102]

[0103] Among them, E(x) represents the homomorphic encryption of x, w i represents the pre-set weight coefficient, g represents the common base number, t i represents the random number generated for the i-th node, the w i satisfy

[0104] S43, the merging node decrypts the merging result C, using the private key sk of the merging node merge Perform homomorphic decryption operations to obtain the final plaintext consensus result M;

[0105] S44, performing data verification on the plaintext consensus result M, wherein the data verification includes recalculating the hash value H(M) of M and comparing it with the hash value before decryption. If they are consistent, the result is considered correct;

[0106] S45. Record the final plaintext consensus result M in the local storage of the merging stage, and generate a transaction hash value H(M) for the generation and verification of the new block.

[0107] In this implementation, the predefined logic of the smart contract includes data access permission management and data sharing rules.

[0108] Embodiment 1:

[0109] In order to verify the feasibility of the present invention in implementation, the present invention was applied to three large hospitals and two research institutions in a certain city to establish a medical data sharing network. Each institution acts as a node, and the nodes participating in data sharing are interconnected through the blockchain network. The whole process includes system initialization, data encryption and segmentation, multi-party computing consensus, result verification and smart contract execution.

[0110] First, during the system initialization phase, all participating institutions obtain identity authentication through registration and generate public-private key pairs for multi-party secure computation. The system initialization settings include Shamir secret sharing scheme parameters, Paillier homomorphic encryption parameters, and the multi-party computation protocol configuration of the optimized GMW protocol.

[0111] Next, the data provider (such as a hospital) encrypts the patient's health data using the Paillier homomorphic encryption algorithm to generate encrypted transaction data. Then, the encrypted data is divided into several shares through the Shamir secret sharing scheme and distributed to each node participating in the data authorization sharing.

[0112] After each node receives a share of the encrypted transaction, it performs distributed computing according to the optimized GMW protocol. During the computing process, the nodes communicate and exchange data through encrypted channels. Each node sends the intermediate results of the calculation to the designated merging node. After the merging node receives all the intermediate results, it merges these results through the optimized GMW protocol to obtain the final consensus result.

[0113] After the consensus result is confirmed to be correct, the merged nodes generate a new block and broadcast the new block to the entire network. The transactions in the new block trigger the execution of the smart contract, which automatically runs in the blockchain network, executes the predefined logic, and records the execution results in the blockchain.

[0114] We conducted a six-month actual application test in the above-mentioned medical data sharing network. During the test, a total of 3,000 patient data were processed, including electronic medical records, diagnostic records, and medical images. The following table shows the data collected during the test and the analysis results:

[0115] Table 1 Test data and result analysis table of the present invention

[0116]

[0117]

[0118] All data remain encrypted during sharing and calculation, and no data leakage has occurred. The security of data storage and transmission of each node has been verified through regular security audits. The privacy protection of patients has achieved 100% coverage, and both data providers and users are satisfied with the privacy protection capabilities of the system. After using the optimized GMW protocol, the calculation time of each node has been significantly shortened. The average calculation time for each piece of data has been reduced from 2 hours in traditional methods to 30 minutes, and the efficiency has increased by 4 times. After receiving the intermediate results, the merging node takes an average of 5 minutes to merge and verify the results through the optimized GMW protocol, and an average of 3 minutes to generate a new block and broadcast it to the entire network, which takes less than 40 minutes in total. During the six-month test period, the system maintained 99.9% of the operating time without major failures. All participating nodes can stably share and calculate data. At the same time, blockchain technology ensures the transparency and immutability of each transaction and calculation result. All data operations are recorded on the chain, and the operation logs and transaction records are clear. Smart contracts automatically execute data authorization and sharing rules, avoiding human intervention and ensuring the fairness and compliance of data operations.

[0119] In summary, the data authorization sharing method based on blockchain and multi-party secure computing provided by the present invention has significant advantages in protecting data privacy, improving computing efficiency, enhancing system stability and achieving data transparency. This method not only solves the problems of insufficient privacy protection, difficult security guarantee, low computing efficiency and lack of trust mechanism in the prior art, but also provides a strong guarantee for the safe sharing and efficient use of medical data, and has broad application prospects.

[0120] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A data authorization sharing method based on blockchain and multi-party secure computing, characterized in that: The steps include: S1. Initialize the system. Nodes participating in data authorization sharing obtain identity authentication through registration and generate public and private key pairs for multi-party secure computing. S2. The data provider encrypts the transaction data using the Paillier homomorphic encryption algorithm to generate encrypted transaction data, and divides the encrypted transaction data into several shares using the Shamir secret sharing scheme; S3. The node participating in data authorization sharing receives the share of the encrypted transaction data and stores it locally, performs distributed computing according to the optimized GMW protocol, and sends the intermediate results of the computing to the designated merging node through an encrypted channel; S4. After receiving all the intermediate results, the merging node merges the intermediate results through the optimized GMW protocol to obtain the final consensus result; S5. After the consensus result is confirmed to be correct, the merged node generates a new block and broadcasts the new block to the entire network; S6. The transaction in the new block triggers the execution of the smart contract, which automatically runs in the blockchain network, executes predefined logic, and records the execution results in the blockchain.

2. According to claim 1, a data authorization sharing method based on blockchain and multi-party secure computing is characterized in that: The system initialization settings include Shamir secret sharing scheme parameters, Paillier homomorphic encryption parameters and optimized GMW protocol multi-party computing protocol configuration; The Shamir secret sharing scheme parameters include the number of split shares N and the minimum number of shares K required to recover data, and satisfy 1≤K≤N; The Paillier homomorphic encryption parameters include two large prime numbers p and q; The multi-party computing protocol configuration of the optimized GMW protocol includes the communication port and IP address of each node, and the random number generator seed required in each round of calculation.

3. According to claim 1, a data authorization sharing method based on blockchain and multi-party secure computing is characterized in that: The S2 specifically includes: S21, the data provider selects transaction data D and pre-processes D; S22. The data provider encrypts the transaction data D using the Paillier homomorphic encryption algorithm to generate encrypted transaction data E(D); the Paillier homomorphic encryption algorithm includes: Select two large prime numbers p and q, and calculate the modulus n = p·q; Calculate λ=lcm(p-1,q-1), where lcm represents the least common multiple; Pick a random number Let the order of g be n; Pick a random number Calculate the encrypted data E(D): E(D)(g m ·r n )modn 2 100. Where m is the plaintext representation of the transaction data D, g and r are the parameters required for encryption, and E(D) represents the result of homomorphic encryption; S23. The data provider divides the encrypted transaction data E(D) into several shares according to the Shamir secret sharing scheme, including: Choose a polynomial f(x) of degree t-1, where t is the minimum number of shares required to recover the secret and f(0) = E(D); Calculate each share S i , the formula is: S i =f(i)modp,i=1,2,…,n1; Where, f(x) = a0+a1x+a2x 2 +…+a t-1 x t-1 , a0=E(D), a1, a2, …, a t-1 is a randomly selected coefficient, i represents a unique identifier assigned to a node; S24, each share S i Securely distributed to each node participating in data authorization sharing.

4. According to claim 1, a data authorization sharing method based on blockchain and multi-party secure computing is characterized in that: The optimized GMW protocol specifically includes: Set the number of protocol calculation rounds N; Each node uses the secret-sharing shares and homomorphically encrypted data to perform local calculations according to the optimized GMW protocol. Multiple rounds of communication and data exchange are required during the calculation process. In each round of calculation, each node sends the intermediate results of the calculation to other nodes through an encrypted channel. After receiving the intermediate results sent by other nodes, each node performs further calculations and repeats this process until the number of protocol calculation rounds N is reached; During the calculation process, each node compresses the communication data according to the preset optimization scheme, and encrypts the intermediate results using the Paillier homomorphic encryption algorithm; After calculating the protocol calculation rounds N times, each node sends the final intermediate result to the designated merging node through an encrypted channel. The merging node is responsible for summarizing the intermediate results of all nodes.

5. According to claim 1, a data authorization sharing method based on blockchain and multi-party secure computing is characterized in that: The S4 specifically includes: S41, aggregate the intermediate results sent by each node participating in data authorization sharing, expressed as: R＝{r1,r2,…,r n} Among them, r i Represents the intermediate result of the i-th node; S42. Apply the characteristics of homomorphic encryption to perform weighted sum calculation on the intermediate results. The combined result C is expressed as: Among them, E(x) represents the homomorphic encryption of x, w i represents the pre-set weight coefficient, g represents the common base number, t i represents the random number generated for the i-th node, the w i satisfy S43, the merging node decrypts the merging result C, using the private key sk of the merging node merge Perform homomorphic decryption operations to obtain the final plaintext consensus result M; S44, performing data verification on the plaintext consensus result M, wherein the data verification includes recalculating the hash value H(M) of M and comparing it with the hash value before decryption. If they are consistent, the result is considered correct; S45. Record the final plaintext consensus result M in the local storage of the merging stage of step S42, and generate a transaction hash value H(M) for the generation and verification of the new block.

6. According to claim 1, a data authorization sharing method based on blockchain and multi-party secure computing is characterized in that: The predefined logic of the smart contract includes data access permission management and data sharing rules.

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