Multi-party real-time auditing method and system for privacy calculation based on block chain

Abstract

The invention discloses a multi-party real-time auditing method and system for privacy calculation based on a block chain, and relates to the technical field of block chains, and the method comprises the steps: obtaining encrypted data, and transmitting the encrypted data to a calculation task based on a verifiable casual transmission mode, according to encryption of the encrypted data, the data provider encrypts the data and then carries out uplink evidence storage, a task initiator describes a calculation task by using a verifiable confusion circuit represented by Three-Halves and provides the calculation task to each data provider for calculation, and the circuit supports splitting. And zero-knowledge proof about the calculation task and encrypted data transmission is generated based on the encrypted data and the calculation task, and the auditing party verifies all the zero-knowledge proof about the calculation task and encrypted data transmission on the upload chain and publicizes an auditing result.

Description

Technical Field

[0001] The present invention relates to the technical field of blockchain, specifically a multi-party real-time auditing method and system for privacy computing based on blockchain. Background Technique

[0002] With the rapid development of digitalization, the amount of data of enterprises and institutions has exploded, and traditional auditing methods face many challenges such as efficiency and trust. In this context, blockchain technology emerges with its characteristics of distributed ledger, immutability, transparency and traceability. It can securely record data such as transactions, and all parties can access the same and trusted data copies within the permitted scope, which provides the possibility for multi-party real-time auditing, enabling different auditing entities to carry out auditing work simultaneously on the blockchain network, greatly improving the timeliness and credibility of auditing.

[0003] The blockchain technology provides support for information interaction in multi-party real-time auditing. Currently, blockchains are mainly divided into two categories, one is the public chain and the other is the consortium chain. In China, the consortium chain is the mainstream of current research. In recent years, various domestic research institutes and Internet companies have attached great importance to the development of China's consortium chain, and various key components applicable to the consortium chain have been developed and put into application.

[0004] How to design the process of multi-party real-time auditing and implement it for the digital asset circulation scenario is the research significance of this patent.

[0005] There are many drawbacks in existing multi-party real-time auditing. On the one hand, it is difficult to ensure the authenticity and integrity of data because the data may be tampered with during transmission or there may be input errors, and the data formats and standards of each auditing party may be different, making data integration difficult and easily leading to data inconsistency. On the other hand, the collaborative efficiency between different auditing parties is relatively low, there are obstacles to information sharing, the communication cost is high, and there may also be trust issues. It is difficult for each party to determine whether the auditing processes and results of other parties are fair and accurate, and the current auditing system has security risks and is easily threatened by network attacks and the like. Summary of the Invention

[0006] To solve the deficiencies mentioned in the above background technique, the purpose of the present invention is to provide a multi-party real-time auditing method and system for privacy computing based on blockchain.

[0007] In the first aspect, the purpose of the present invention can be achieved through the following technical solutions: A multi-party real-time auditing method for privacy computing based on blockchain, the method includes the following steps:

[0008] Obtain encrypted data and transmit the encrypted data to the computing task based on a verifiable oblivious transfer method. Among them, the encryption of the encrypted data is to encrypt the data by the data provider and then store it on the chain for evidence. The task initiator uses a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for calculation, and the circuit supports splitting;

[0009] Generate a zero-knowledge proof for the computing task and the transmission of the encrypted data based on the encrypted data and the computing task. The auditor verifies all the zero-knowledge proofs for the computing task and the transmission of the encrypted data uploaded to the chain and publicizes the audit results.

[0010] Combined with the first aspect, in some implementation manners of the first aspect, the method further includes: The process of the data provider encrypting the data and storing it on the chain for evidence includes:

[0011] The data provider commits the data using the Petersen commitment to generate a commitment value, combines the commitment value with the time stamp, signs the value, and uploads it to the chain.

[0012] Combined with the first aspect, in some implementation manners of the first aspect, the method further includes: The process of the task initiator using a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for calculation includes:

[0013] The Three-Halves garbled circuit uses the label sharding technique and a fixed XOR offset Δ to divide the label into two parts. The garbled circuit is a two-party circuit, and both parties generate mask values based on the verifiable MAC value and the Beaver triple. Both parties respectively based on Δ A and Δ B , and then combine the label sharding to complete the generation of the garbled shares and the garbled table. Finally, construct the sharing shares t A and t B of the matrix t to identify the position of the output label in the garbled row;

[0014] During the distribution process, the information of the output wires obtained by each party is encrypted and recorded for subsequent auditing and verification.

[0015] Combined with the first aspect, in some implementation manners of the first aspect, the method further includes: The verifiable oblivious transfer method is as follows:

[0016] Transmit data between the data provider and the computing party, and transmit tasks and results between the task provider and the computing party;

[0017] Add a verification process before the interaction is finally completed. This process only needs to use the parameters in the transmission process and does not require additional interaction. If it does not match the expected result, the verification will fail and the corresponding key cannot be decrypted, such as Figure 4 shown: The receiver generates verification parameters based on its private data and sends them to the sender; the sender uses the commitment uploaded by the receiver to the blockchain to verify whether the verification parameters are consistent with the pre-authentication data. If the verification passes, the sender generates an encrypted transmission result; otherwise, the protocol is aborted.

[0018] Combined with the first aspect, in some implementation manners of the first aspect, the method further includes: The generation process of the zero-knowledge proof for the computing task and the encrypted data transmission is as follows:

[0019] The system generates two challenges using the commitment on the chain. The prover responds to the challenges using the input key and output key of the garbled circuit respectively. Since the input key is generated from the data and the output key is calculated, the former can prove the consistency of the data and the input data, and the latter can check the correctness of the calculation process. If both responses are valid, it proves that this calculation process is correct.

[0020] Combined with the first aspect, in some implementation manners of the first aspect, the method further includes: The process of the auditor verifying all the zero-knowledge proofs for the computing task and the encrypted data transmission uploaded to the chain:

[0021] After the generated zero-knowledge smart contract is uploaded to the blockchain, any auditor with the permission to run the contract can run the smart contract to audit this calculation process, and the audit record will be left on the chain.

[0022] When the verification process discovers a cheater, record the cheater's account and prohibit them from participating in subsequent calculations.

[0023] In a second aspect, in order to achieve the above object, the present invention discloses a multi-party real-time auditing system for privacy computing based on blockchain, including:

[0024] A data transmission module, configured to obtain encrypted data and transmit the encrypted data to the computing task based on a verifiable oblivious transfer method. Among them, the encryption of the encrypted data is to encrypt the data by the data provider and then store it on the chain for evidence. The task initiator uses a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for calculation, and the circuit supports splitting;

[0025] An auditing module, configured to generate a zero-knowledge proof for the computing task and the encrypted data transmission based on the encrypted data and the computing task. The auditor verifies all the zero-knowledge proofs for the computing task and the encrypted data transmission uploaded to the chain and publicizes the audit results.

[0026] In another aspect of the present invention, in order to achieve the above object, a terminal device is disclosed, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. The memory stores a computer program capable of running on the processor. When the processor loads and executes the computer program, the above-mentioned multi-party real-time auditing method for privacy computing based on blockchain is adopted.

[0027] In yet another aspect of the present invention, in order to achieve the above object, a computer-readable storage medium is disclosed. The computer-readable storage medium stores a computer program. When the computer program is loaded and executed by a processor, the above-mentioned multi-party real-time auditing method for privacy computing based on blockchain is adopted.

[0028] Advantages of the present invention:

[0029] The present invention uses proof elements that do not include sensitive information for non-interactive zero-knowledge proof. After one audit, the audit result can be publicly disclosed on the chain, reducing the waste of resources caused by repeated audits. By implementing the method of uploading the privacy computing result to the chain, the non-repudiation and traceability of the privacy computing result are guaranteed. After achieving reliable one-to-one data interaction, the method of verifiable oblivious transfer and the characteristics of garbled circuits are used to store and audit the intermediate values of the calculation. Since zero-knowledge proof is a garbled circuit-like algorithm, after completing the distributed computing part of this method, it can be combined with the splitting algorithm of garbled circuits to achieve multi-party real-time auditing. Further, after contractizing the audit process, real-time auditing on the chain can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings;

[0031] Figure 1 It is a schematic flowchart of the method of the present invention;

[0032] Figure 2 It is a schematic application design diagram of the auditing system of the present invention;

[0033] Figure 3 It is a schematic overall data transmission framework design diagram of the present invention;

[0034] Figure 4 It is a schematic design diagram of verifiable oblivious transfer of the present invention;

[0035] Figure 5 It is a schematic system structure diagram of the present invention.

[0036] Figure 6 It is a schematic diagram of applying this framework for ciphertext operation and decryption in an embodiment of the present invention. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] Embodiment 1:

[0039] Next, the relevant terms related to the embodiments of the present application will be introduced:

[0040] Blockchain (English name: blockchain or block chain) is a block-chain storage, immutable, secure and trustworthy decentralized distributed ledger. It combines technologies such as distributed storage, peer-to-peer transmission, consensus mechanism, and cryptography. It records transactions and information through an ever-growing data block chain (Blocks) to ensure the security and transparency of data. Blockchain originated from Bitcoin and is the underlying technology of Bitcoin. Since the initial Bitcoin network, blockchain has gradually evolved into a global technology, attracting global attention and investment. Subsequently, the emergence of new-generation blockchain platforms such as Ethereum has further expanded the application fields. The characteristics of blockchain include decentralization, immutability, transparency, security, and programmability. Each data block is linked to the previous block to form a continuous chain, ensuring the integrity of the transaction history. Smart contract technology makes blockchain programmable and supports a wider range of applications. Blockchain has been widely used in fields such as finance, supply chain, healthcare, and real estate. Although it still faces scalability and regulatory challenges, it has become a powerful tool to change traditional business and social models and has great potential for the future.

[0041] As Figure 1 shown, a multi-party real-time auditing method for privacy computing based on blockchain, the method includes the following steps:

[0042] S101: Obtain encrypted data, and transmit the encrypted data to the computing task based on a verifiable oblivious transfer method. Among them, the encryption of the encrypted data is to encrypt the data by the data provider and store it on the chain for evidence. The task initiator uses a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for computing, and the circuit supports splitting;

[0043] The process by which the data provider encrypts the data and stores it on the chain for evidence includes:

[0044] The data provider makes a commitment to the data using the Petersen commitment, generates a commitment value, combines the commitment value with a timestamp, signs the value, and uploads it to the chain.

[0045] The process by which the task initiator uses a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for computing includes:

[0046] The Three-Halves garbled circuit uses label sharding technology and a fixed XOR offset Δ to divide the label into two parts, thereby reducing communication overhead. This garbled circuit is a two-party circuit. The two parties generate masked values based on verifiable MAC values (taking the MAC value of A as an example, ) and Beaver triples to ensure that the two parties jointly generate circuit masks and cannot be tampered with, preventing malicious adversaries from forging garbled circuits. Each party based on Δ A and Δ B , and then combines label sharding to complete the generation of garbled shares and garbled tables. Finally, based on the masked values, the sharing shares of matrix t (t A and t B ) are constructed to identify the positions of output labels in the garbled rows, ensuring that the computing party can only decrypt valid rows.

[0047] During the distribution process, the information of the output wires obtained by each party is encrypted and recorded for subsequent auditing and verification.

[0048] The verifiable oblivious transfer method is as follows:

[0049] Data is transmitted between the data provider and the computing party, and tasks and results are transmitted between the task provider and the computing party;

[0050] Before the final interaction is completed, an additional verification process is added. This process only requires the use of the parameters in the transmission process and does not require additional interaction. If it does not match the expected result, the verification will fail and the corresponding key cannot be decrypted as Figure 4 shown: The receiver generates verification parameters based on its private data and sends them to the sender; the sender uses the commitment uploaded by the receiver to the blockchain to verify whether the verification parameters are consistent with the pre-authenticated data. If the verification passes, the sender generates an encrypted transmission result; otherwise, the protocol is aborted.

[0051] S102: Generate a zero-knowledge proof for the computing task and the transmission of encrypted data based on the encrypted data and the computing task. The auditor verifies all the zero-knowledge proofs for the computing task and the transmission of encrypted data uploaded to the chain and publicizes the audit results.

[0052] The generation process of the zero-knowledge proof for the computing task and encrypted data transmission is as follows:

[0053] The system generates two challenges using the commitments on the chain. The prover responds to the challenges using the input key and output key of the garbled circuit respectively. Since the input key is generated from the data and the output key is calculated, the former can prove the consistency between the data and the input data, and the latter can check the correctness of the calculation process. If both responses are valid, it proves that this calculation process is correct.

[0054] The process by which the auditor verifies all zero-knowledge proofs for computing tasks and encrypted data transmission uploaded to the chain:

[0055] After the generated zero-knowledge smart contract is uploaded to the blockchain, any auditor with the permission to run the contract can run the smart contract to audit this calculation process, and the audit record will be left on the chain.

[0056] Specifically, the solution of the present invention will be further elaborated through embodiments below:

[0057] The present invention supports audit work in multiple scenarios: Currently, it has adapted to 6 application scenarios, including audit work in fields such as finance, law, and carbon certificates. It supports multi-party secure computing and multi-party auditing. By splitting the audit and computing tasks, it supports distributing the computing tasks to different participating parties to accelerate the computing work. And the audit task itself can also be regarded as a special type of computing task. For a general type of audit task, it supports abstracting the audit tasks borne by parties who do not trust each other into computing tasks and storing the audit tasks as evidence.

[0058] Embodiment 2: Second, as Figure 5 shown, to achieve the above object, the present invention discloses a multi-party real-time audit system for privacy computing based on blockchain, including:

[0059] A data transmission module 11, configured to obtain encrypted data and transmit the encrypted data to the computing task based on a verifiable oblivious transfer method. Among them, the encryption of the encrypted data is to encrypt the data by the data provider and then store it on the chain as evidence. The task initiator uses a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for calculation, and the circuit supports splitting;

[0060] An audit module 12, configured to generate a zero-knowledge proof for the computing task and encrypted data transmission based on the encrypted data and the computing task. The auditor verifies all zero-knowledge proofs for the computing task and encrypted data transmission uploaded to the chain and publicizes the audit results.

[0061] Specifically, the present invention can be used to provide security protection for multi-party secure computing tasks. Specifically, the server party provides computing tasks, the client party with data uses its own data to execute the computing tasks, and the client party without data can, with the permission of the client party with data, use its data to execute the computing tasks. The specific steps are as follows:

[0062] The client party commits the data and then uploads it to the blockchain.

[0063] (Optional) For multiple client parties with the same data, the server decides whether to split the target circuit.

[0064] The client party and the server party obtain the input keys of the garbled circuit through oblivious transfer, and calculate the output keys together with the input keys of other servers (instead of the data of other parties). The output keys are returned to the server, and the server obtains the secret value to complete the computing task.

[0065] The server uses the on-chain data to generate a smart contract to challenge the client, and the client responds with the key in its hand.

[0066] The complete interaction process is recorded on the blockchain as a log, and each auditing party can conduct audits by querying the log.

[0067] Compared with the existing method that combines traditional Yao's circuit and zero-knowledge proof, without splitting the circuit, the specific proof size and proof time are comparable to the existing proof methods, but the communication volume during the computing process is significantly reduced. According to theoretical derivation, it can be reduced to 18.75% of the existing method at the lowest, and can reach 30% in actual tests. After splitting the circuit, the circuit scale obtained by each party is reduced, and the running time in multi-party secure computing tasks is optimized according to the number of circuit splits.

[0068] Based on the same inventive concept, the present invention further provides a computer device, which includes: one or more processors, and a memory for storing one or more computer programs; the program includes program instructions, and the processor is configured to execute the program instructions stored in the memory. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is used to implement one or more instructions. Specifically, it is used to load and execute one or more instructions in the computer storage medium to implement the above method.

[0069] It should be further noted that, based on the same inventive concept, the present invention further provides a computer storage medium, on which a computer program is stored, and the computer program, when run by a processor, executes the above method. The storage medium may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may, for example, but not be limited to, an electrical, magnetic, optical, electrical, magnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the computer-readable storage medium include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a Random Access Memory (RAM), a Read Only Memory (ROM), an Erasable Programmable Read Only Memory (EPROM or flash memory), an optical fiber, a portable compact disk read only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, the computer-readable storage medium may be any tangible medium that contains or stores a program, and the program may be used by or in combination with an instruction execution system, apparatus, or device.

[0070] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0071] The foregoing has shown and described the basic principles, main features and advantages of the present disclosure. Those skilled in the art should understand that the present disclosure is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present disclosure. Without departing from the spirit and scope of the present disclosure, the present disclosure will have various changes and improvements, and these changes and improvements fall within the scope of the present disclosure claimed.

Claims

1. A multi-party real-time auditing method for privacy computing based on blockchain, characterized in that The method includes the following steps: Obtain encrypted data, and transmit the encrypted data to the computing task based on a verifiable oblivious transfer method. Among them, the encryption of the encrypted data is to encrypt the data by the data provider and then store it on the chain for verification. The task initiator uses a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for calculation, and the circuit supports splitting; Generate a zero-knowledge proof regarding the computing task and the transmission of encrypted data based on the encrypted data and the computing task. The auditor verifies all the zero-knowledge proofs regarding the computing task and the transmission of encrypted data uploaded to the chain, and publicizes the audit results.

2. The multi-party real-time auditing method for privacy computing based on blockchain according to claim 1, wherein, The process by which the data provider encrypts the data and stores it on the chain for verification includes: The data provider commits the data using the Petersen commitment to generate a commitment value, combines the commitment value and the timestamp, signs the value, and uploads it to the chain.

3. The multi-party real-time auditing method for privacy computing based on blockchain according to claim 1, characterized in that The process by which the task initiator uses a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for calculation includes: The Three-Halves garbling circuit uses the label fragmentation technique and a fixed XOR offset Δ to divide the label into two parts. The garbling circuit is a two-party circuit, and both parties generate masked values based on verifiable MAC values and Beaver triples. Both parties respectively based on Δ A and Δ B , and then combine the label fragmentation to complete the generation of garbled shares and garbled tables. Finally, based on the masked values, the sharing shares t A and t B of matrix t are constructed to identify the positions of the output labels in the garbled rows; During the distribution process, the information of the output wires obtained by each party is encrypted and recorded for subsequent auditing and verification.

4. The multi-party real-time auditing method for privacy computing based on blockchain according to claim 1, characterized in that The verifiable oblivious transfer method is as follows: Transmit data between the data provider and the computing party, and transmit the task and the result between the task provider and the computing party; Add a verification process before the final interaction is completed. Only the parameters during the transmission process are required, and no additional interaction is needed. If it does not match the expected result, the verification will fail and the corresponding key cannot be decrypted. The receiving party generates verification parameters based on its private data and sends them to the sending party; the sending party uses the commitment uploaded by the receiving party to the blockchain to verify whether the verification parameters are consistent with the pre-authenticated data. If the verification passes, the sending party generates an encrypted transmission result; otherwise, the protocol is aborted.

5. The multi-party real-time auditing method for privacy computing based on blockchain according to claim 1, characterized in that The generation process of the zero-knowledge proof regarding the computing task and the transmission of encrypted data is as follows: The system generates two challenges using the commitment on the chain. The prover responds to the challenges using the input key and the output key of the garbled circuit respectively. Since the input key is generated from the data and the output key is calculated, the former can prove the consistency of the data and the input data, and the latter checks the correctness of the calculation process. If both responses are valid, it proves that this calculation process is correct.

6. The multi-party real-time auditing method for privacy computing based on blockchain according to claim 1, wherein, The process by which the auditor verifies all the zero-knowledge proofs regarding the computing task and the transmission of encrypted data uploaded to the chain: After uploading the generated smart contract to the blockchain, any auditor with the permission to run the contract audits the current calculation process by running the smart contract, and the audit record will be left on the chain; When a cheater is found during the verification process, record the account of the cheater and prohibit it from participating in subsequent calculations.

7. A multi-party real-time auditing system for privacy computing based on blockchain, characterized in that, Includes: A data transmission module, configured to obtain encrypted data and transmit the encrypted data to a computing task based on a verifiable oblivious transfer method, wherein the encryption of the encrypted data is performed by encrypting the data by a data provider and storing it on the chain for certification, and the task initiator uses a verifiable garbled circuit represented by Three-Halves to describe the computing task and provide it to each data provider for computing, and the circuit supports splitting; An audit module, configured to generate zero-knowledge proofs regarding the computing task and the encrypted data transmission based on the encrypted data and the computing task, and an auditor verifies all the zero-knowledge proofs regarding the computing task and the encrypted data transmission uploaded to the chain and publicizes the audit results.

8. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, A computer program capable of running on a processor is stored in the memory, and when the processor loads and executes the computer program, the method for multi-party real-time auditing of privacy computing based on a blockchain according to any one of claims 1 to 6 is adopted.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is loaded and executed by the processor, the method for multi-party real-time auditing of privacy computing based on a blockchain according to any one of claims 1 to 6 is adopted.

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