Privacy protection method for block chain bidding and tendering process based on trusted execution environment

Abstract

The invention discloses a privacy protection method for a block chain bidding and tendering process based on a trusted execution environment. According to the method, identity privacy and data privacy in the bidding and tendering process of a block chain system are analyzed; the bidding and tendering process is subjected to standard division, and privacy information appearing in each stage is subjected to safety protection. According to the invention, the execution of the smart contract in the block chain is transferred to the feasible execution environment by using the trusted execution environment technology, which is helpful for protecting the related privacy information involved in the execution of the smart contract. Therefore, privacy leakage of the bidding and tendering users is effectively prevented, and the method has important research significance and application value for privacy protection of the block chain bidding and tendering users.

Description

Technical Field

[0001] The present invention belongs to the technical field of blockchain security, and specifically relates to a privacy protection method for a blockchain bidding process based on a trusted execution environment. Background Art

[0002] Blockchain is a decentralized network technology. In recent years, blockchain networks have developed rapidly, and distributed application systems have also received widespread attention. As a decentralized network ledger, blockchain networks have many excellent features. The decentralization, traceability, and immutability it provides make it a highly reliable and secure machine, and thus it is widely cited in various fields. Blockchain is constantly combined with various fields, such as the Internet of Things, supply chain management, and bidding systems, which helps to maintain the transparency of application development, improve data availability, and reduce development costs. With the continuous development of the Internet, bidding has gradually shifted from an offline model to an online model. In order to ensure the openness and transparency of the bidding process and increase the credibility of the bidding process, blockchain can be combined with bidding. This can greatly improve the efficiency of the bidding process, achieve efficient data sharing, and provide high availability for the system, effectively prevent single point failures, and ensure the smooth progress of the bidding process. However, the high transparency of blockchain will cause a certain degree of leakage of the data privacy of each participant in the bidding process, such as the price provided by the bidder, the qualifications and conditions of the bidder, and the results of the bidder's quality assessment. At the same time, it will expose the identity privacy of the participants, which will greatly affect the interests of the bidder. Therefore, how to effectively protect privacy in the blockchain bidding process is an urgent problem to be solved.

[0003] The Trusted Execution Environment is a hardware-based secure computing resource. It is a secure area on the processor that is parallel to the operating system and has separate computing resources, such as CPU usage and memory space. Therefore, the host operating system cannot intervene and observe the internal running code, which provides integrity and confidentiality for the internal running code and data. Using the Trusted Execution Environment technology, the on-chain calculation in the blockchain can be converted to off-chain calculation, thereby effectively protecting the content involving the privacy information of the participants, such as the price provided by the bidder, the qualifications of the bidder, and the results of the bidder's quality assessment. Using the Trusted Execution Environment technology, the plain text of the bidding information will not be recorded on the blockchain, but the information and bidding results will be encrypted. Therefore, only the participants with relevant permissions can view it, thereby effectively protecting privacy information. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a privacy protection method for the blockchain bidding process based on a trusted execution environment, so as to solve the problem of privacy leakage in the blockchain bidding process; the present invention makes full use of the trusted execution environment technology to calculate and process sensitive information, and uses order-preserving encryption technology to encrypt the bidding results, thereby providing security for the privacy of bidding users.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: a privacy protection method for a blockchain bidding process based on a trusted execution environment, the method comprising the following steps:

[0006] 1) Generate security parameters in the setup phase: Initialize the entire method, set algorithm security parameters, initialize the blockchain and create relevant bidding channels, assign blockchain addresses and corresponding public and private keys to each participant to facilitate subsequent encrypted transmission of privacy data.

[0007] 2) Bidding information is uploaded to the blockchain during the bidding stage: the bidding party uploads the bidding documents and corresponding bidding parameters. The bidding documents will be quickly shared on the blockchain so that interested bidders can participate in the bidding. The bidding party sets relevant parameters on the smart contract based on the bidding information and deploys the smart contract to the blockchain to prepare for subsequent steps.

[0008] 3) Bidding information is encrypted and uploaded to the chain during the bidding stage: the bidder obtains the corresponding bidding documents, generates the corresponding bidding documents and bidding parameters according to the bidding requirements, and calls the smart contract in step 2) to obtain the corresponding bidding qualifications. The bidder applies for calculation to the trusted execution environment server, and the smart contract will return the qualification results under the server call.

[0009] 4) Calculate bidding qualifications and results during the bid evaluation phase: The bidder that has passed the qualification review in step 3) calls the smart contract again to obtain the bid evaluation results. The bidder applies for calculation to the trusted execution environment server. The smart contract in step 2) will return the bid evaluation results under the server call. The bidder encrypts the results using an order-preserving encryption algorithm and uploads them to the blockchain network for comparison.

[0010] 5) The winning bidder is announced and the bidding information is verified during the bid opening stage: each participant compares the encrypted scores generated in step 4) with each other, and the winning bidder is selected based on the comparison results of the encrypted scores. The winning bidder will encrypt the bidding documents and upload them to the blockchain network for verification by the tendering party. After the verification is passed, the winning bidder is officially determined, thus completing the bidding.

[0011] Among them, 1) the security parameters are generated in the setting stage, as follows:

[0012] 11) Organization registration: If each participant needs to use the blockchain network, the tenderer and bidder need to join the blockchain network as an organization. Each participant will be authenticated according to the organization information. After passing the authentication, each participant will be assigned a corresponding public key, private key and address on the blockchain.

[0013] 12) Blockchain network initialization: Before the formal bidding process, the blockchain needs to be initialized. For each bidding, a channel will be initialized according to the participants and the bidding name, allowing each participant to join the channel.

[0014] 13)ORE encryption initialization: In the preparation phase, the key pair (k, π) required for encryption will be set for the Order-Revealing Encryption (ORE) algorithm for subsequent encryption operations.

[0015] 14) Organize the deposit and withdrawal of funds: Before participating in the bidding, each participant will deposit and withdraw an initial amount of funds into the blockchain for subsequent deposit payment, and perform fund storage operations for each participant.

[0016] The privacy information involved in step 1) mainly includes:

[0017] Security parameters and initialization information. The initialization parameters used by this method to build a security algorithm should be discarded to prevent damage and exploitation by attackers.

[0018] The relevant private keys of the participants are used to decrypt the encrypted letters sent by the parties. When the private keys are stolen, the relevant encrypted information will also be leaked. The private keys should be kept properly by the participants.

[0019] Among them, 2) bidding information is uploaded to the blockchain during the bidding stage, as follows:

[0020] 21) Submitting bidding documents: As the bidding initiator, the bidding party is responsible for uploading the bidding documents for each bidder to obtain bidding information, generating the corresponding contract according to the bidding party's address and bidding documents, and generating a designated address for the bidding documents for the convenience of the participants to view and store evidence.

[0021] 22) Smart contract deployment: Deploy the smart contract generated in 21) to the blockchain. The contract address will be used as a parameter for contract interaction, and a pair of public and private keys will be generated for the contract for encrypted information transmission.

[0022] 23) Obtain bidding documents: Obtain the corresponding bidding documents according to the file address to prepare for the subsequent bidding of each bidder.

[0023] Among them, 3) bidding information is encrypted and uploaded to the blockchain during the bidding stage, as follows:

[0024] 31) Generate bidding documents: Generate corresponding bidding documents and bidding parameters based on the obtained bidding documents. In order to protect privacy, the bidding parameters will be encrypted before transmission.

[0025] 32) Qualification evaluation: The qualification of the bidder is evaluated according to the bidding requirements. When all bidding conditions are met, the bidder will obtain the pass mark of pi.pass←true.

[0026] 33) Deposit payment: A deposit will be collected from qualified bidders so that subsequent bidders can participate in the bidding normally. If there is any dishonest behavior in the subsequent bidding process, the deposit will be deducted and will not be returned;

[0027] The privacy information involved in step 3) mainly includes:

[0028] User identity information involves relevant information of the enterprise, including real name, address, unified social credit code, including in the actual bidding process, knowing the identity information of the opponent in advance can make relevant estimates or analysis, and relevant user information and enterprise information should not be disclosed in the bidding process;

[0029] The specific bid price and corresponding time period, including the specific price amount provided by the bidder to the tenderer during the bidding process and the corresponding delivery time, should not be visible to third parties;

[0030] Qualification verification information provided by the bidder: The qualification verification information involves the qualification assessment of the bidder's company, the assessment results of the bidder's assets and the credit assessment results. It is sensitive information for the bidder and should not be disclosed to other bidders.

[0031] Among them, 4) the bid evaluation stage calculates the bidding qualifications and results, as follows:

[0032] 41) Evaluate bids: Score each bid document according to the specific scoring rules of the bidding documents. The bid documents will be converted into scores and presented.

[0033] 42) Encrypted evaluation score: Encrypt the score in 41). ORE will encrypt the score into the left encrypted score pi.rpoint and the right encrypted score pi.lpoint, and encrypt the left encrypted evaluation score of each bidding document with the corresponding bidder’s public key, so that the encrypted score can be displayed in the subsequent bid winning statement.

[0034] 43) Score comparison: The result scores of each bid document that has passed the qualification evaluation will be compared. The bidder, as the caller, will know its rank among all the bid documents, but will not get any other information.

[0035] The privacy information involved in step 4) mainly includes:

[0036] Evaluation results of the bidder: The evaluation results are the final score of the bid documents, which involve important privacy information such as the bidder's product quality and should be encrypted to protect data privacy.

[0037] Among them, 5) the bid opening stage announces the winning bidder to verify the bidding information, as follows:

[0038] 51) Statement of Winning Bidder: The winning bidder makes a statement of winning. First, the identity of the winning bidder is verified to confirm that the winning bidder is consistent with the previously calculated result, and the winning bidder is required to collect the agreement recognition ACKi of the remaining losing bidders. After the collection is completed, all bidders reach an agreement on the identity of the winning bidder.

[0039] 52) Submit the winning bid document: The winning bidder is required to encrypt the winning bid document with the public key of the tenderer and upload it for the tenderer to verify. The address is generated based on the uploaded file for subsequent review and verification.

[0040] 53) Verify the successful bidder: The tenderer will verify the successful bidder's documents, including the qualification and score verification of the bidders. After confirmation, the tenderer will send an agreement confirmation ACKtender, and the successful bidder will confirm the completion.

[0041] 54) Deposit refund: After the entire bidding process is completed, the deposit will be refunded to all participants who have participated in the bidding process and abided by the bidding rules. All deposits will be automatically returned to the original account;

[0042] The privacy information involved in step 5) mainly includes:

[0043] Bidding documents of the successful bidder: The successful bidder needs to upload the bidding documents to the tendering party for verification. The specific details of the bidding documents, such as the final price of the winning bid, should not be obtained by other bidders.

[0044] During the execution of smart contracts, sensitive information privacy calculations are transferred to a trusted execution environment, while retaining the online public verifiability of the blockchain to ensure the fairness of the bidding results. The details are as follows:

[0045] Obtaining the qualifications of bidding users during the bidding stage:

[0046] After each bidder uploads the bidding parameters to the blockchain, the blockchain network will send the relevant parameters to the smart contract. The smart contract will start the qualification review process, transfer the evaluation process from the chain to the chain, and pass the relevant qualification review parameters to the TEE trusted execution environment server. In this process, the TEE server will first activate the host main program and receive the relevant parameters. The main program will judge the compliance of the parameters. After passing, it will create an Enclave responsible for performing the qualification review to execute the task. The Enclave will use its own private key P sk After decrypting the parameters, Enclave will calculate sensitive data for each bidder in a secure hardware environment to determine whether the bidder meets the bidding requirements. Finally, the result will be encrypted and returned to the host program. After obtaining the result, the host program will store the result on the chain, thus completing the qualification review in TEE.

[0047] Evaluation of bid documents of bidders during the bid evaluation phase:

[0048] After each bidder passes the qualification review, the second batch of encrypted parameters will be sent to the blockchain, including the specific information of the bidding documents. The blockchain will also send the relevant parameters to the bid evaluation smart contract, and the smart contract will start the bid evaluation process. The evaluation parameters are transferred from the chain to the off-chain. In this process, the TEE server will create the host program and generate the Enclave again, and call the Enclave program. After comprehensively evaluating and summing each indicator of the bidding document, the evaluation results will be sequentially revealed and encrypted (ORE) for subsequent comparison and proof. Finally, the TEE server will pass the results to the blockchain network, thus completing the evaluation of the bidding documents in the TEE.

[0049] Combine trusted execution environment and sequence-revealing encryption to ensure the privacy and security of the bidding process on the blockchain, as follows:

[0050] Effective combination of trusted execution environment and sequence disclosure encryption:

[0051] The privacy protection of the bidding process uses a trusted execution environment and sequential disclosure encryption technology. In order to expand the use of blockchain technology, it is necessary to make corresponding adjustments and changes to the trusted execution environment and sequential disclosure encryption technology. In the present invention, the present invention realizes the combination of online and offline in a trusted execution environment and the separation of the encryption process and the comparison process in sequential disclosure encryption. In the process of calling the Host program and Enclave program of TEE, the initial security parameter acquisition of ORE is changed to a more secure random number initialization inside TEE. In addition, the setting of ore_blk_ciphertext is further promoted so that the structure can be used in TEE and blockchain. The traditional ORE method is based on the comparison of single data of the same user. In the privacy protection method of the blockchain bidding process based on a trusted execution environment, the offline encryption of multiple users in TEE and the online comparison method in the blockchain can be realized, which ensures the reasonable division of online and offline tasks.

[0052] Beneficial effects of the present invention:

[0053] The present invention makes full use of blockchain and trusted execution environment technology, combines the verifiability of blockchain with the privacy protection technology of trusted execution environment, and applies it to the bidding process. This method can realize the openness and transparency of the bidding process, efficient execution and privacy protection of participants, which is conducive to the wider application of blockchain technology.

[0054] Specifically, there are the following advantages:

[0055] 1) Enhanced security and privacy protection: The trusted execution environment TEE provides a secure execution environment that ensures the confidentiality and integrity of the code and data processed in the environment. This is especially important for blockchain because it protects the code of smart contracts from being leaked while ensuring the privacy of data processing.

[0056] 2) Solve the execution problem of smart contracts: Due to the limited processing power of blockchain, complex algorithms are difficult to execute on the chain. TEE can make up for this limitation and provide stronger computing power while maintaining data privacy and security.

[0057] 3) Improve bidding efficiency: TEE can perform complex calculations off-chain and then publish the results on the blockchain, which can reduce the computational burden of the blockchain itself and improve overall efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 is a diagram of the method architecture of the present invention,

[0059] Figure 2 is a timing diagram of the present invention,

[0060] Figure 3 This is a diagram showing an example of a host program in the TEE of the present invention.

[0061] Figure 4 This is a diagram showing an example of an enclave program in the TEE of the present invention. DETAILED DESCRIPTION

[0062] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0063] Example 1: Reference Figure 1 As shown, the present invention is a privacy protection method for a blockchain bidding process based on a trusted execution environment, and the method comprises the following steps:

[0064] 1) Generate security parameters in the setup phase: Initialize the entire method, set algorithm security parameters, initialize the blockchain and create relevant bidding channels. Assign blockchain addresses and corresponding public and private keys to each participant to facilitate subsequent encrypted transmission of private data.

[0065] like Figure 2 As shown, stage 1) specifically needs to complete four tasks:

[0066] 11) Organization registration: If each participant needs to use the blockchain network, the tenderer and bidder need to join the blockchain network as an organization. Each participant is authenticated according to the organization information. After passing the authentication, each participant will be assigned a corresponding public key, private key and address on the blockchain.

[0067] 12) Blockchain network initialization: Before the formal bidding process, the blockchain needs to be initialized. For each bidding, a channel will be initialized according to the participants and the bidding name, allowing each participant to join the channel.

[0068] 13)ORE encryption initialization: The preparation phase sets the key pair (k, π) required for encryption for the Order-Revealing Encryption (ORE) algorithm for subsequent encryption operations.

[0069] 14) Organize deposit and withdrawal of funds: Before participating in the bidding, each participant will deposit and withdraw an initial amount of funds into the blockchain for subsequent deposit payment. Perform fund storage operations for each participant.

[0070] 2) Bidding information is uploaded to the blockchain during the bidding stage: the bidding party uploads the bidding documents and corresponding bidding parameters, and the bidding documents will be quickly shared on the blockchain so that interested bidders can participate in the bidding. The bidding party sets relevant parameters on the smart contract based on the bidding information and deploys the smart contract to the blockchain to prepare for the subsequent steps.

[0071] like Figure 3 As shown, phase 2) specifically requires the completion of three tasks:

[0072] 21) Submit bidding documents: As the initiator of the bidding, the tenderer is responsible for uploading the bidding documents for each bidder to obtain bidding information, generating the corresponding contract based on the tenderer's address and bidding documents, and generating a designated address for the bidding documents for the convenience of the participating parties to view and store evidence.

[0073] 22) Smart contract deployment: Deploy the smart contract generated in 21) to the blockchain. The contract address will be used as a parameter for contract interaction, and a pair of public and private keys will be generated for the contract for encrypted information transmission.

[0074] 23) Obtain bidding documents: Obtain the corresponding bidding documents according to the file address to prepare for the subsequent bidding of each bidder.

[0075] 3) Bidding information is encrypted and uploaded to the chain during the bidding stage: The bidder obtains the corresponding bidding documents and generates the corresponding bidding documents and bidding parameters according to the bidding requirements. The smart contract in step 2) is called to obtain the corresponding bidding qualifications. The bidder applies for calculation to the trusted execution environment server, and the smart contract will return the qualification results under the server call.

[0076] like Figure 4 As shown, phase 3) specifically requires the completion of three tasks:

[0077] 31) Generate bidding documents: Generate corresponding bidding documents and bidding parameters based on the obtained bidding documents. In order to protect privacy, the bidding parameters will be encrypted before transmission.

[0078] 32) Qualification assessment: The bidders will be assessed for qualifications according to the bidding requirements. When all bidding conditions are met, the bidder will obtain the pass flag of pi.psaa←true.

[0079] 33) Deposit payment: A deposit will be collected from qualified bidders so that subsequent bidders can participate in the bidding normally. If there is any dishonest behavior in the subsequent bidding process, the deposit will be deducted and will not be returned.

[0080] 4) Calculate bidding qualifications and results during the bid evaluation phase: The bidder that has passed the qualification review in step 3) calls the smart contract again to obtain the bid evaluation results. The bidder applies for calculation to the trusted execution environment server, and the smart contract in step 2) will return the bid evaluation results under the server call. The bidder encrypts the results through ORE and uploads them to the blockchain network for comparison.

[0081] Phase 4) requires the completion of three specific tasks:

[0082] 41) Evaluate bids: Each bid document will be scored according to the specific scoring rules of the tender documents, and the bid documents will be converted into scores for presentation.

[0083] 42) Encrypted evaluation score: Encrypt the score in 41) and ORE will encrypt the score into the left encrypted score pi.rpoint and the right encrypted score pi.rpoint. And encrypt the left encrypted evaluation score of each bidding document with the corresponding bidder's public key so that the encrypted score can be displayed in the subsequent winning bid announcement.

[0084] 43) Score comparison: The result scores of each bid document that has passed the qualification evaluation are compared. The bidder, as the caller, will know its rank among all the bid documents, but will not get any other information.

[0085] 5) The bid opening stage announces the winning bidder to verify the bidding information: each participant compares the encrypted scores generated in step 4). The winning bidder is selected based on the comparison of the encrypted scores. The winning bidder will encrypt and upload the bidding documents to the blockchain network for verification by the tendering party. After the verification is passed, the winning bidder is officially determined, thus completing the bidding.

[0086] Phase 5) requires the completion of four specific tasks:

[0087] 51) Statement of Winning Bidder: The winning bidder will make a statement of winning. First, the identity of the winning bidder will be verified to confirm that the winning bidder is consistent with the previously calculated result. The winning bidder will also be required to collect the agreement recognition ACKi of the other losing bidders. After the collection is completed, all bidders reach an agreement on the identity of the winning bidder.

[0088] 52) Submit winning bid documents: The winning bidder is required to encrypt the winning bid documents with the public key of the tendering party and upload them for verification by the tendering party. An address will be generated based on the uploaded file for subsequent review and verification.

[0089] 53) Verify the successful bidder: The tenderer will verify the successful bidder's documents, including the qualification and score verification of the bidders. After confirmation, the tenderer will send an agreement confirmation ACKtender, and the successful bidder will confirm the completion.

[0090] 54) Deposit refund: After the entire bidding process is completed, the deposit will be refunded to all participants who have participated in the bidding process and abided by the bidding rules. All deposits will be automatically refunded to the original account.

[0091] The present invention has many specific application paths. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A privacy protection method for blockchain bidding process based on a trusted execution environment, characterized in that: The method comprises the following steps: 1) Generate security parameters in the setup phase: Initialize the entire method, set algorithm security parameters, initialize the blockchain and create relevant bidding channels, assign blockchain addresses and corresponding public and private keys to each participant to facilitate subsequent encrypted transmission of privacy data. 2) Bidding information is uploaded to the blockchain during the bidding stage: the bidding party uploads the bidding documents and corresponding bidding parameters. The bidding documents will be quickly shared on the blockchain so that interested bidders can participate in the bidding. The bidding party sets relevant parameters on the smart contract based on the bidding information and deploys the smart contract to the blockchain to prepare for subsequent steps. 3) Bidding information is encrypted and uploaded to the chain during the bidding stage: the bidder obtains the corresponding bidding documents, generates the corresponding bidding documents and bidding parameters according to the bidding requirements, and calls the smart contract in step 2) to obtain the corresponding bidding qualifications. The bidder applies for calculation to the trusted execution environment server, and the smart contract will return the qualification results under the server call. 4) Calculate bidding qualifications and results during the bid evaluation phase: The bidder that has passed the qualification review in step 3) calls the smart contract again to obtain the bid evaluation results. The bidder applies for calculation to the trusted execution environment server. The smart contract in step 2) will return the bid evaluation results under the server call. The bidder encrypts the results using an order-preserving encryption algorithm and uploads them to the blockchain network for comparison. 5) The winning bidder is announced and the bidding information is verified during the bid opening stage: each participant compares the encrypted scores generated in step 4) with each other, and the winning bidder is selected based on the comparison results of the encrypted scores. The winning bidder will encrypt the bidding documents and upload them to the blockchain network for verification by the tendering party. After the verification is passed, the winning bidder is officially determined, thus completing the bidding.

2. The privacy protection method for the blockchain bidding process based on a trusted execution environment according to claim 1 is characterized in that: 1) The security parameters are generated in the setup phase, as follows: 11) Organization registration: If each participant needs to use the blockchain network, the tenderer and bidder need to join the blockchain network as an organization. Each participant will be authenticated according to the organization information. After passing the authentication, each participant will be assigned a corresponding public key, private key and address on the blockchain. 12) Blockchain network initialization: Before the formal bidding process, the blockchain needs to be initialized. For each bidding, a channel will be initialized according to the participants and the bidding name, allowing each participant to join the channel. 13)ORE encryption initialization: In the preparation phase, the key pair (k, π) required for encryption will be set for the Order-Revealing Encryption (ORE) algorithm for subsequent encryption operations. 14) Organize deposit and withdrawal of funds: Before participating in the bidding, each participant will deposit and withdraw an initial amount of funds into the blockchain for subsequent deposit payment, and perform fund storage operations for each participant. The privacy information involved in step 1) mainly includes: Security parameters and initialization information. The initialization parameters used by this method to build a security algorithm should be discarded to prevent damage and exploitation by attackers. The relevant private keys of the participants are used to decrypt the encrypted letters sent by the parties. When the private keys are stolen, the relevant encrypted information will also be leaked. The private keys should be kept properly by the participants.

3. The privacy protection method for the blockchain bidding process based on a trusted execution environment according to claim 1 is characterized in that: 2) Bidding information is uploaded to the blockchain during the bidding stage, as follows: 21) Submitting bidding documents: As the bidding initiator, the bidding party is responsible for uploading the bidding documents for each bidder to obtain bidding information, generating the corresponding contract according to the bidding party's address and bidding documents, and generating a designated address for the bidding documents for the convenience of the participants to view and store evidence. 22) Smart contract deployment: Deploy the smart contract generated in 21) to the blockchain. The contract address will be used as a parameter for contract interaction, and a pair of public and private keys will be generated for the contract for encrypted information transmission. 23) Obtain bidding documents: Obtain the corresponding bidding documents according to the file address to prepare for the subsequent bidding of each bidder.

4. The privacy protection method for the blockchain bidding process based on a trusted execution environment according to claim 1 is characterized in that: 3) Bidding information is encrypted and uploaded to the blockchain during the bidding stage. The details are as follows: 31) Generate bidding documents: Generate corresponding bidding documents and bidding parameters based on the obtained bidding documents. In order to protect privacy, the bidding parameters will be encrypted before transmission. 32) Qualification evaluation: The qualification of the bidder is evaluated according to the bidding requirements. When all bidding conditions are met, the bidder will obtain the pass flag of pi.pass←true. 33) Deposit payment: A deposit will be collected from qualified bidders so that subsequent bidders can participate in the bidding normally. If there is any dishonest behavior in the subsequent bidding process, the deposit will be deducted and will not be returned; The privacy information involved in step 3) mainly includes: User identity information involves relevant information of the enterprise, including real name, address, unified social credit code, including in the actual bidding process, knowing the identity information of the opponent in advance can make relevant estimates or analysis, and relevant user information and enterprise information should not be disclosed in the bidding process; The specific bid price and corresponding time period, including the specific price amount provided by the bidder to the tenderer during the bidding process and the corresponding delivery time, should not be visible to third parties; Qualification verification information provided by the bidder: The qualification verification information involves the qualification assessment of the bidder's company, the assessment results of the bidder's assets and the credit assessment results. It is sensitive information for the bidder and should not be disclosed to other bidders.

5. The privacy protection method for the blockchain bidding process based on a trusted execution environment according to claim 1 is characterized in that: 4) The bidding qualifications and results are calculated during the bid evaluation stage, as follows: 41) Evaluate bids: Score each bid document according to the specific scoring rules of the bidding documents. The bid documents will be converted into scores and presented. 42) Encrypted evaluation score: Encrypt the score in 41). ORE will encrypt the score into the left encrypted score pi.rpoint and the right encrypted score pi.lpoint, and encrypt the left encrypted evaluation score of each bidding document with the corresponding bidder’s public key, so that the encrypted score can be displayed in the subsequent bid winning statement. 43) Score comparison: The result scores of each bid document that has passed the qualification evaluation will be compared. The bidder, as the caller, will know its rank among all the bid documents, but will not get any other information. The privacy information involved in step 4) mainly includes: Evaluation results of the bidder: The evaluation results are the final score of the bid documents, which involve important privacy information such as the bidder's product quality and should be encrypted to protect data privacy.

6. The privacy protection method for the blockchain bidding process based on a trusted execution environment according to claim 1 is characterized in that: 5) The winning bidder will be announced and the bidding information will be verified during the bid opening stage. The details are as follows: 51) Statement of Winning Bidder: The winning bidder makes a statement of winning. First, the identity of the winning bidder is verified to confirm that the winning bidder is consistent with the previously calculated result, and the winning bidder is required to collect the agreement recognition ACKi of the remaining losing bidders. After the collection is completed, all bidders reach an agreement on the identity of the winning bidder. 52) Submit the winning bid document: The winning bidder is required to encrypt the winning bid document with the public key of the tenderer and upload it for the tenderer to verify. The address is generated based on the uploaded file for subsequent review and verification. 53) Verify the successful bidder: The tenderer will verify the successful bidder's documents, including the qualification and score of the bidder. After confirmation, the tenderer will send an ACKtender, and the successful bidder will confirm the completion. 54) Deposit refund: After the entire bidding process is completed, the deposit will be refunded to all participants who have participated in the bidding process and abided by the bidding rules. All deposits will be automatically refunded to the original account.

7. The privacy protection method for the blockchain bidding process based on a trusted execution environment according to claim 1 is characterized in that: During the execution of smart contracts, sensitive information privacy calculations are transferred to a trusted execution environment, while retaining the online public verifiability of the blockchain to ensure the fairness of the bidding results. The details are as follows: Obtaining the qualifications of bidding users during the bidding stage: After each bidder uploads the bidding parameters to the blockchain, the blockchain network will send the relevant parameters to the smart contract. The smart contract will start the qualification review process, transfer the evaluation process from the chain to the chain, and pass the relevant qualification review parameters to the TEE trusted execution environment server. The TEE server will first activate the host main program and receive the relevant parameters. The main program will judge the compliance of the parameters. After passing, it will create an Enclave responsible for performing the qualification review to execute the task. The Enclave will use its own private key P sk After decrypting the parameters, Enclave will calculate sensitive data for each bidder in a secure hardware environment to determine whether the bidder meets the bidding requirements. Finally, the result will be encrypted and returned to the host program. After obtaining the result, the host program will store the result on the chain, thus completing the qualification review in TEE. Evaluation of bid documents of bidders during the bid evaluation phase: After each bidder passes the qualification review, a second batch of encrypted parameters will be sent to the blockchain, including specific information of the bidding documents. The blockchain will also send the relevant parameters to the bid evaluation smart contract. The smart contract starts the bid evaluation process, and the evaluation parameters are transferred from the chain to the off-chain. During this process, the TEE server will create the host program and generate the Enclave and call the Enclave program again. After comprehensively evaluating and summing each indicator of the bidding document, the evaluation results will be sequentially revealed and encrypted (ORE) for subsequent comparison and proof. Finally, the TEE server will pass the results to the blockchain network, thus completing the bid document evaluation in the TEE.

8. The privacy protection method for the blockchain bidding process based on a trusted execution environment according to claim 1 is characterized in that: Combine trusted execution environment and sequence-revealing encryption to ensure the privacy and security of the bidding process on the blockchain, as follows: Effective combination of trusted execution environment and sequence disclosure encryption: The privacy protection of the bidding process uses a trusted execution environment and sequential disclosure encryption technology, realizing the combination of online and offline in a trusted execution environment and the separation of the encryption process and the comparison process in sequential disclosure encryption. In the process of calling the Host program and Enclave program of TEE, the initial security parameter acquisition of ORE is changed to a more secure random number initialization inside TEE.

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