A Cross-chain Sharing Method for Notary Blockchains Based on Zero-Knowledge Proof

Abstract

The present invention belongs to the technical field of blockchain, and discloses a cross-chain sharing method for a notary blockchain based on zero-knowledge proof. First, a single data requester publishes a data requirement description, and multiple data providers respond to the requirement simultaneously; then the shared data is chunk-hashed, and the integrity of the shared data is verified through zero-knowledge proof, and then a quality factor is calculated to evaluate the reputation value. Then, the historical reputation value and quality factor of each node are weighted and summed to calculate the reputation value of each node. The nodes are sorted according to the reputation value, and formal notaries are selected. Finally, multiple data providers respectively transmit the shared data to the target chain, and the data requester decrypts the data to complete data sharing. The present application improves the overall efficiency of cross-chain operations and reduces the risk of sensitive information leakage by introducing zero-knowledge proof in cross-chain data verification.

Description

Technical Field

[0001] The present invention belongs to the technical field of blockchain, and specifically relates to a cross-chain sharing method for a notary blockchain based on zero-knowledge proof. Background Art

[0002] In the fields of blockchain and privacy computing, zero-knowledge proof (ZKP) technology is widely used to protect user data privacy while ensuring the verifiability of the computing process. However, in the notary mechanism of cross-chain transactions, simply relying on zero-knowledge proof still has certain limitations, such as: high computational and storage overheads, inability to adapt to dynamic cross-chain environments, lack of a flexible error handling mechanism, etc.

[0003] Chinese Patent Application CN202410629420 discloses a blockchain cross-chain supervision method for a notary group. This application elects and manages the notary group through the PageRank algorithm integrating reputation values, solves the problem of the centralization risk existing in the notary mode, and realizes the effective supervision of the cross-chain supervision transaction system. However, this application has the following deficiencies: (1) The notary group needs to obtain a large amount of storage space for nodes, which affects the operating efficiency of the system; (2) Transaction information may be leaked in the use of the PageRank algorithm; (3) The election result of the notary group loses fairness and transparency, affecting the fairness and security of the entire system.

[0004] Chinese Patent Application CN2023104734817 discloses a privacy protection cross-chain transaction verification method based on zero-knowledge proof, which realizes a privacy protection cross-chain transaction verification method. However, this patent application has the following technical defects: (1) As the number of blockchains increases and the running time grows, it affects the real-time performance and efficiency of cross-chain transactions; (2) Each cross-chain transaction needs to be verified for its authenticity and legality through multiple encryption algorithms, consuming a large amount of computing resources; (3) If there are loopholes in the relay chain's management of the service list, it may lead to illegal transactions passing the review, affecting the trust level of cross-chain transactions and reducing the credibility of the cross-chain transaction system.

[0005] In summary, the existing cross-chain technologies have not fully supported this many-to-one scenario, resulting in limitations in the flexibility and scalability of cross-chain data sharing. It is of great significance to study how to achieve fair calculation and credible verification of notary reputation while protecting the privacy of notaries and efficiently process in a many-to-one scenario. Summary of the Invention

[0006] To solve the above technical problems, the present application provides a cross-chain sharing method for a notary blockchain based on zero-knowledge proof. This method improves the overall efficiency of cross-chain operations and reduces the risk of sensitive information leakage by introducing zero-knowledge proof in cross-chain data verification.

[0007] To achieve the above object, the present application is implemented through the following technical solutions:

[0008] The present application is a notary blockchain cross-chain sharing method based on zero-knowledge proof. The notary blockchain cross-chain sharing method uses blockchain technology to record and store data, and specifically includes the following steps:

[0009] Step 1: A single data requester publishes a data requirement description, clarifying the data type, scope, and usage rights. Multiple data providers respond to the requirement simultaneously and respectively announce the data format, access policy, and privacy protection conditions of the single data requester and the data format, access policy, and privacy protection conditions of multiple data providers;

[0010] Step 2: Hash the blockchain cross-chain shared data in chunks, verify the integrity of the shared data through zero-knowledge proof, ensure that the data format and usage rights are compliant, declare the authenticity of the shared data, and generate zero-knowledge proof;

[0011] Step 3: Calculate the quality factors of the notary nodes in the blockchain cross-chain sharing to evaluate the reputation value, where the quality factors include accuracy score, stability score, and contribution score;

[0012] Step 4: Perform a weighted sum of the historical reputation values of the notary nodes in each blockchain cross-chain sharing and the quality factors of the notary nodes in each blockchain cross-chain sharing calculated in Step 3, and calculate the reputation value of the notary nodes in each blockchain cross-chain sharing;

[0013] Step 5: According to the reputation value calculated in Step 4, sort all the notary nodes in the blockchain cross-chain sharing from high to low according to the reputation value, and select the top three notary nodes with the highest scores as official notaries;

[0014] Step 6: Multiple data providers encrypt and transmit the shared data to the target chain respectively, and the data requester decrypts the data to complete the many-to-one data sharing of the blockchain cross-chain.

[0015] A further improvement of the present application is that: in Step 3, the accuracy score is the ratio of the correct shared data submitted by the notary nodes in the blockchain cross-chain sharing to the shared data sent by the data providers:

[0016]

[0017] wherein, is the number of correct certified data sharings submitted by the notary nodes in the blockchain cross-chain sharing, is the total number of data sharings submitted by the notary nodes in the blockchain cross-chain sharing;

[0018] To protect privacy, the notary node in blockchain cross-chain sharing generates a zero-knowledge proof π when submitting a proof. Generating the zero-knowledge proof π indicates that the notary node in blockchain cross-chain sharing will only disclose the final accuracy score numerical value and the corresponding zero-knowledge proof π, without exposing the shared content or sharing details.

[0019] A further improvement of this application is that in step 3, the stability score is used to measure the online stability of the notary node in blockchain cross-chain sharing:

[0020]

[0021] where, is the actual online duration of the notary node in blockchain cross-chain sharing, is the total duration of services required by the notary node in blockchain cross-chain sharing. To protect privacy, the notary node in blockchain cross-chain sharing will locally record its own online situation, and define a constraint statement to ensure that the actual online duration of the notary node is less than the total duration of services required by the notary node, ensuring is the actual online duration of the notary node. Then, using , and the public parameter CRS, generate a proof π through the Prove algorithm of ZK-SNARK;

[0022] The notary node in blockchain cross-chain sharing knows its actual online duration and the total duration , and calculates . The notary node in blockchain cross-chain sharing only discloses the stability score and the zero-knowledge proof corresponding to the stability score, without exposing the online log or duration information.

[0023] A further improvement of this application is that in step 3, verify the contribution score :

[0024]

[0025] where, is the set of other nodes except the recognized node i that submit proofs by the recognized nodes in this round, is the reputation score of the recognized node . Each recognized node submits its own reputation value to the data requester, and through the zero-knowledge proof, it shows that the node knows its own reputation value , and this reputation value conforms to the predetermined reputation calculation rule. After verifying the zero-knowledge proof, the smart contract calculates , during this process, the specific approval relationships or reputation details between nodes will not be exposed.

[0026] A further improvement of this application lies in that: the specific steps for calculating the reputation value of the notary nodes in each blockchain cross-chain sharing in step 4 are as follows:

[0027] Step 4.1: Calculate the quality factor of the notary nodes in the blockchain cross-chain sharing: The quality factor of the notary in each blockchain cross-chain sharing is the accuracy score , the stability score and the verification contribution score weighted sum. Calculate the quality factor of the notary nodes in each blockchain cross-chain sharing :

[0028]

[0029] Among them, are all weights, and ;

[0030] Step 4.2: Reputation value calculation and update: Assume that there are notary nodes in the blockchain cross-chain sharing. The initial reputation value of the notary node in the blockchain cross-chain sharing is . The reputation value of the notary node in the cross-chain transaction is :

[0031]

[0032] Among them, is the reputation value of the notary node in the th round. is the quality factor, reflecting the cross-chain service performance of the node in this round. The parameter is the reputation accumulation weight factor, used to control the influence of historical reputation on the current reputation.

[0033] A further improvement of this application lies in that: step 5 specifically includes the following steps:

[0034] Step 5.1: First, perform zero-knowledge proof on the shared data to confirm the authenticity and availability of the shared data, receive the public parameters and proofs , and call the verification function

[0035]

[0036] Among them, It is the public reference string of the zero-knowledge succinct non-interactive argument of knowledge (zk-SNARK). It is the root hash of the hash tree, i.e., the public data fingerprint. It is the zero-knowledge proof generated by the data provider. The verifier uses the public parameters and the proof , and checks whether all zero-knowledge proofs are valid through the verification function. If the verification is successful, it returns 1, indicating that the zero-knowledge proof is valid; otherwise, it returns 0, indicating that the zero-knowledge proof is invalid.

[0037] Step 5.2: The data requester sorts the reputation values of all notary nodes in the blockchain cross-chain sharing in descending order to generate a sorted list. If the reputation values of multiple nodes are the same, the node with more historical service times is preferentially selected. The top three notaries with the highest scores are selected as the official notaries from the sorted list. If there are offline nodes among the top 3, they will be filled in sequentially.

[0038] The beneficial effects of this application are as follows:

[0039] Compared with the traditional solution that needs to retain the complete historical sharing records, by introducing zero-knowledge proofs in cross-chain data verification, this application can store only small-scale data such as hash values and zero-knowledge proofs on the chain, effectively reducing the storage and bandwidth pressure of the blockchain network and improving the overall efficiency of cross-chain operations.

[0040] This application adds the scenario of multiple data providers, emphasizing the advantages of zero-knowledge proofs when multiple data providers participate simultaneously.

[0041] The notaries of this application perform verification based on zero-knowledge proofs, and can review the legality and data compliance of cross-chain data sharing, etc. Use zero-knowledge proofs to confirm the authenticity and integrity of the data, avoid the exposure of the original data, and reduce the risk of sensitive information leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is the flowchart of the method of this application.

[0043] Figure 2 It is the schematic diagram of the blockchain cross-chain data sharing method of this application.

[0044] Figure 3 It is the flowchart of the zero-knowledge proof of this application.

[0045] Figure 4 It is the flowchart of the reputation value calculation of this application.

[0046] Figure 5 It is the time comparison chart for sharing a batch of data all at once and sharing them one by one in batches in sequence. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] The following will disclose the embodiments of the present invention with drawings. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. That is to say, in some embodiments of the present invention, these practical details are not necessary.

[0048] like Figure 1 - Figure 2 As shown, the present application is a notary blockchain cross-chain sharing method based on zero-knowledge proof. The notary blockchain cross-chain sharing method uses blockchain technology to record and store data. The notary blockchain cross-chain sharing method specifically includes the following steps:

[0049] Step 1: A single data demander publishes a data demand description, clearly defining the data type, scope, and usage rights. Multiple data providers respond to the demand at the same time and publish the data format, access policy, and privacy protection conditions of the single data demander and the data format, access policy, and privacy protection conditions of multiple data providers respectively;

[0050] Data demanders: Data demanders are users, smart contracts, or applications that want to access or use certain data. Data demanders make data demands and obtain data based on the system's permissions and rules.

[0051] Description of the required data: clarify the type, scope and usage rights of the required data. Applied to industrial scenarios, the data types are divided into equipment sensor data, production log data, production energy consumption data, etc.; the data scope specifies the time range, equipment range, and parameter range of the data requirements; data usage rights distinguish between the subjects of read and write permissions.

[0052] Data provider: A data provider is a node or organization that owns and can share data. In cross-chain data sharing, the data provider is responsible for storing data and providing data to qualified data demanders based on access policies and permission management rules.

[0053] Provide data description: specify the format and access policy of each data. Applied to industrial scenarios, the format describes the data input format, such as encoding format, JSON format, CSV format, which is convenient for the recipient to parse the data; the access policy describes the access rights of the data, such as different levels of access rights for equipment suppliers, data analysts, and third-party auditors.

[0054] Blockchain network: A distributed system consisting of multiple blockchain nodes that uses blockchain technology to record and store data. Each blockchain network usually has its own consensus mechanism, data structure, and smart contract rules. Each data sharing involves a source chain responsible for providing data, a notarization chain that verifies data, and a target chain that receives data.

[0055] Source Chain: The blockchain where the data is initially stored, which is responsible for providing the data. When the data requester requests data, the system extracts the corresponding data from the source chain and prepares for cross-chain transmission.

[0056] Notary Chain: A blockchain specifically used for cross-chain data verification and notarization. Its main role is to ensure the authenticity, integrity, and consistency of the data. In cross-chain data sharing, the notary chain usually consists of multiple notaries. These nodes are responsible for verifying the authenticity of the cross-chain data and providing zero-knowledge proofs to ensure that the data is not tampered with or leaked during transmission between different blockchains.

[0057] Target Chain: The blockchain where the data is finally stored or used. It is responsible for receiving the data requested by the data requester and performing corresponding processing or storage.

[0058] Step 2: Hash the cross-chain shared data of the blockchain in chunks, verify the integrity of the shared data through zero-knowledge proof, ensure that the data format and usage permissions are compliant, declare the authenticity of the shared data, and generate a zero-knowledge proof;

[0059] Zero-Knowledge Proof: Allows the prover to prove the truth of a statement to the verifier without revealing specific information. In the fields of blockchain and privacy computing, zero-knowledge proof technology is widely used to protect user data privacy while ensuring the verifiability of the computing process. The zero-knowledge proof is proven by the ZK-SNARK algorithm, as Figure 3 shown.

[0060] Construction Constraints: First, hash the data input by the data provider in chunks, construct a hash tree to generate a root hash as the global data fingerprint. Then construct a data compliance statement, which includes data existence, format compliance, and permission compliance.

[0061] Generate Proof: Convert the statement into an arithmetic circuit as the public parameter part, and combine it with the private data part of the knowledge composed of the complete content of the original shared data and the key verified after data encryption to generate a proof .

[0062] Step 3: Under zero-knowledge proof, calculate the quality factor of the notary nodes in the blockchain cross-chain sharing to evaluate the reputation value, where the quality factor includes accuracy score, stability score, and contribution score, as Figure 4 shown. The specific operations are as follows:

[0063] Accuracy Score is the ratio of the correct shared data submitted by the notary nodes in the blockchain cross-chain sharing to the shared data sent by the data provider:

[0064]

[0065] Among them, is the data sharing number of the correct proof submitted by the notary node in blockchain cross-chain sharing, is the total data sharing number submitted by the notary node in blockchain cross-chain sharing;

[0066] To protect privacy, the notary node in blockchain cross-chain sharing generates a zero-knowledge proof π when submitting a proof. Generating the zero-knowledge proof π indicates that the notary node in blockchain cross-chain sharing will only disclose the final accuracy score value and the corresponding zero-knowledge proof π, without exposing the shared content or sharing details.

[0067] Stability score is used to measure the stability of the notary node online in blockchain cross-chain sharing:

[0068]

[0069] Among them, is the actual online duration of the notary node in blockchain cross-chain sharing, is the total duration required for the services of the notary node in blockchain cross-chain sharing. To protect privacy, the notary node in blockchain cross-chain sharing will locally record its own online situation, and define a constraint statement to ensure that the actual online duration of the notary node is less than the total duration required for the services of the notary node, ensuring is the actual online duration of the notary node. Then, use 、 and the public parameter CRS to generate a proof π through the Prove algorithm of ZK-SNARK.

[0070] The notary node in blockchain cross-chain sharing knows its actual online duration and the total duration , and calculates . The notary node in blockchain cross-chain sharing only discloses the stability score and the zero-knowledge proof corresponding to the stability score, without exposing detailed online logs or duration information.

[0071] Verify the contribution score :

[0072]

[0073] Among them, is the set of other nodes except the recognized node i that submit proofs by the recognized nodes in this round, is the reputation score of the recognized node is the recognized node , and each recognized node Submit one's own reputation value to the smart contract and prove through zero-knowledge proof that the node knows its own reputation value , and this reputation value conforms to the predetermined reputation calculation rules. After the smart contract verifies the zero-knowledge proof, it calculates . During this process, the specific approval relationships or reputation details between nodes will not be exposed.

[0074] Step 4: Perform a weighted sum of the historical reputation values of the notary nodes in each blockchain cross-chain sharing and the quality factors of the notary nodes in each blockchain cross-chain sharing calculated in Step 3 to calculate the reputation value of the notary nodes in each blockchain cross-chain sharing;

[0075] Define the quality factor as the weighted sum of the accuracy score , stability score and verification contribution score , and calculate the quality factor of the notary nodes in each blockchain cross-chain sharing :

[0076]

[0077] Among them, are all weights, and . The specific score of the notary nodes in each blockchain cross-chain sharing is calculated according to the performance of the notary nodes in that blockchain cross-chain sharing. The accuracy score reflects the correct rate of the cross-chain proofs provided by the nodes, the stability score measures the online rate of the node's services, and the verification contribution score represents the recognition degree of the proofs submitted by the node by other nodes.

[0078] Reputation value calculation and update: Assume that there are notary nodes in the blockchain cross-chain sharing of the blockchain network, and the initial reputation value of the notary node in the blockchain cross-chain sharing is , and the reputation value of the notary node in the cross-chain transaction is :

[0079]

[0080] Among them, is the reputation value of the notary node in the th round, is the quality factor, reflecting the cross-chain service performance of the node in this round. The parameter is the reputation accumulation weight factor, used to control the influence of historical reputation on the current reputation. In this embodiment, it is set as The value between 0.7 and 0.9 indicates that the historical reputation has a strong impact on the current reputation, while the new service performance will have an updated impact on the reputation.

[0081] Step 5: According to the reputation values calculated in Step 4, sort all the notary nodes in the blockchain cross-chain sharing in descending order of reputation values, and select the top three notary nodes with the highest scores as official notaries.

[0082] Before officially selecting the notaries, first perform zero-knowledge proof on the shared data to confirm the authenticity and availability of the shared data, and receive the public parameters and proofs , and call the verification function

[0083]

[0084] Among them, is the public parameter of the zero-knowledge succinct non-interactive knowledge argument zk-SNARK, is the root hash of the hash tree, i.e., the public data fingerprint, is the zero-knowledge proof generated by the data provider. The verifier uses the public parameters and proofs , and checks whether all the zero-knowledge proofs are valid through the verification function. If the verification is successful, return 1, indicating that the zero-knowledge proof is valid; otherwise, return 0, indicating that the zero-knowledge proof is invalid.

[0085] The data requester, i.e., the smart contract, sorts the reputation values of all the notary nodes in the blockchain cross-chain sharing in descending order to generate a sorted list. If the reputation values of multiple nodes are the same, the node with more historical service times is preferred.

[0086] Select the top three notary nodes with the highest scores from the sorted list as official notaries. If there are offline nodes among the top 3, they will be filled in sequentially.

[0087] Step 6: Multiple data providers respectively encrypt the shared data and transmit it to the target chain, and the data requester decrypts the data to complete the data sharing.

[0088] The data provider obtains the data D on the source chain, encrypts it using the symmetric encryption algorithm to generate the encrypted data, and generates the data hash commitment H(D) to ensure that the data is not tampered with during the transmission process. The data provider encrypts the symmetric key using the public key of the data requester on the target chain to generate the key ciphertext. Only the data requester with the corresponding private key can decrypt and obtain the corresponding symmetric key.

[0089] The data requester uses its own private key to decrypt the key ciphertext to obtain the data.

[0090] Calculate the reputation value of the current notary according to the notary reputation score calculation formula and update it dynamically. Notaries with high reputation values can receive a share of the cross-chain transaction fees, or receive additional incentive tokens, and can participate in cross-chain data verification with priority.

[0091] To verify the cost and effectiveness of the method proposed in this application, a simulation experiment was conducted on this application.

[0092] Compare the time and Gas costs respectively. The time comparison is as Figure 5 .

[0093] In terms of time efficiency, many-to-one data sharing is significantly better than one-to-one data sharing.

[0094] Many-to-one sharing batches the existence verification of multiple data in the source chain into one on-chain operation by constructing a global Merkle tree, avoiding multiple independent hash path verifications and reducing the number of on-chain interactions. The simulation results prove that when the data volume ≥ 50, the time efficiency of the many-to-one mode is higher than that of the traditional one-to-one mode, and the larger the data volume, the more obvious this advantage is.

[0095] In terms of Gas cost, the difference in Gas consumption between the one-to-one mode and the many-to-one mode for different data volumes is shown in Table 1.

[0096] Table 1 Gas cost comparison

[0097]

[0098] Under the same data volume, the Gas consumption of the many-to-one mode is lower than that of the one-to-one mode. And whether it is a small data volume (10 - 50) or a large data volume (100 and above), the Gas optimization effect of the many-to-one mode is always stable at 48% - 54%.

[0099] Since the Merkle tree template and zero-knowledge circuit pre-generated in the initialization stage in the many-to-one mode can be reused for subsequent data updates, avoiding the multiple repeated processes in the one-to-one mode and reducing the resource overhead. It can be seen that the many-to-one mode is more suitable for high-frequency and large-data-volume sharing requirements, which can significantly reduce the computing and storage costs on the blockchain and improve the efficiency of data sharing.

[0100] The above is only the implementation manner of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A cross-chain sharing method for a notary blockchain based on zero-knowledge proof. The cross-chain sharing method for the notary blockchain uses blockchain technology to record and store data, and is characterized in that: The notary blockchain cross-chain sharing method specifically includes the following steps: Step S1: A single data demander publishes a data demand description, and multiple data providers respond to the demand at the same time, and publish the data format, access policy and privacy protection conditions of the single data demander and the data format, access policy and privacy protection conditions of multiple data providers respectively; Step S2: hash the cross-chain shared data in blocks, verify the integrity of the shared data through zero-knowledge proof, declare the authenticity of the shared data, and generate a zero-knowledge proof; Step S3, calculating the quality factor of the notary node in the cross-chain sharing of the blockchain to evaluate the reputation value, where the quality factor includes accuracy score, stability score and contribution score; Step S4: weighted sum the historical reputation value of the notary node in each blockchain cross-chain sharing and the quality factor of the notary node in each blockchain cross-chain sharing calculated in step S3 to calculate the reputation value of the notary node in each blockchain cross-chain sharing; Step S5: According to the reputation value calculated in step S4, all notary nodes in the cross-chain sharing of blockchain are sorted from high to low according to the reputation value, and the three notaries with the highest scores are selected as official notaries; Step S6: Multiple data providers encrypt the shared data and transmit it to the target chain respectively, and the data demander decrypts the data to complete the many-to-one data sharing across blockchains; Among them, the accuracy score is the ratio of the correct shared data submitted by the notary nodes in blockchain cross-chain sharing to the shared data sent by the data provider: Among them, C correct is the data sharing number of the correct proof submitted by the notary node in blockchain cross-chain sharing, and C total is the total data sharing number submitted by the notary node in blockchain cross-chain sharing; For privacy protection, the notary node in blockchain cross-chain sharing generates a zero-knowledge proof π when submitting a proof, indicating that the notary node in blockchain cross-chain sharing will only disclose the final accuracy score value and the corresponding zero-knowledge proof π, without exposing the shared content or sharing details; Stability Score Used to measure the stability of the notary nodes being online in blockchain cross-chain sharing: Among them, T online is the actual online duration of the notary node in blockchain cross-chain sharing, and T total is the total duration of services required by the notary node in blockchain cross-chain sharing. The notary node in blockchain cross-chain sharing will locally record its own online situation. Defining a constraint statement means ensuring that the actual online duration of the notary node is less than the total duration of services required by the notary node, ensuring that T online is the actual online duration of the notary node, and a proof π is generated through the Prove algorithm of ZK-SNARK; The notary node in blockchain cross-chain sharing knows its actual online duration T online and the total duration T total , and calculates The notary node in blockchain cross-chain sharing only discloses the stability score and the corresponding zero-knowledge proof of the stability score, without exposing the online log or duration information; Verify contribution score Among them, U i is the set of other nodes except the recognized node i that recognize the proof submitted by the recognized node i, is the reputation score of the recognized node j. Each recognized node j submits its own reputation value to the data requester and proves through zero-knowledge proof that the node j knows its own reputation value and this reputation value conforms to the predetermined reputation calculation rule. After verifying the zero-knowledge proof, the smart contract calculates During this process, the specific recognition relationships or reputation details between nodes will not be exposed; The step S4 of calculating the reputation value of the notary node in each blockchain cross-chain sharing specifically includes the following steps: Step 4.

1. Calculate the quality factor of the notary nodes in blockchain cross-chain sharing: The quality factor of each notary node in blockchain cross-chain sharing is the accuracy score stability score and verification contribution score which is the weighted sum of, and calculate the quality factor of each notary node in blockchain cross-chain sharing Among them, w1, w2, w3 are all weights, and w1+w2+w3=1; Step 4.

2. Reputation value calculation and update: Assume that there are N notary nodes in the blockchain network for cross-chain sharing. The initial reputation value of notary node i in the blockchain cross-chain sharing is The reputation value of notary node i in the blockchain cross-chain sharing in a cross-chain transaction is Among them, is the reputation value of the notary node i in the t-th round of blockchain cross-chain sharing, is the quality factor, and the parameter α ∈ (0, 1) is the reputation accumulation weight factor, which is used to control the influence of historical reputation on the current reputation.

2. The cross-chain sharing method of a notary blockchain based on zero-knowledge proof according to claim 1, characterized in that: Step S5 specifically includes the following steps: Step 5.1: Perform zero-knowledge proof on the shared data to confirm the authenticity and availability of the shared data, receive the public parameters and zero-knowledge proof π, and call the verification function. Among them, CRS is the public reference string of zero-knowledge succinct non-interactive knowledge argument zk-SNARK, R is the root hash of the hash tree, that is, the public data fingerprint, π is the zero-knowledge proof generated by the data provider, and the verifier uses the public parameters and zero-knowledge proof π to check whether all zero-knowledge proofs are established through the verification function. If the verification is successful, it returns 1, indicating that the zero-knowledge proof is valid, otherwise it returns 0, indicating that the zero-knowledge proof is invalid; Step 5.2: The data demander sorts the reputation values ​​of all notary nodes in the cross-chain sharing of the blockchain in descending order, generates a sorted list, and selects the three notaries with the highest scores from the sorted list as official notaries. If there are offline nodes among the top three, they will be replaced in due course.

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