Bidding data management method and system based on block chain

Abstract

The invention relates to the technical field of data management methods, in particular to a bid inviting data management method and system based on a block chain. According to the technical scheme, the system comprises a data storage module, a network communication module, an intelligent contract module, a user interface module and a data backup and recovery module. Through a block chain distributed account book technology and an asymmetric encryption algorithm, data integrity, authenticity, confidentiality and security are improved, and data are prevented from being stolen or tampered; the bid invitation data management system based on the block chain enables the bid invitation data to be traced by authorized parties, and the transparency and fairness of the bid invitation process are improved; meanwhile, automatic execution of a bid invitation process is realized through an intelligent contract, efficiency and fairness are improved, transaction cost and risk are reduced, transparency and credibility of the bid invitation process are enhanced, and availability and integrity of bid invitation data and stable operation of a block chain network are ensured and Byzantine node risk is resisted based on a P2P network architecture and a PBFT algorithm.

Description

Technical Field

[0001] The present invention relates to the technical field of data management methods, and in particular to a bidding data management method and system based on blockchain. Background Art

[0002] In the traditional bidding data management model, data is usually stored in a centralized server, which brings many serious problems. On the one hand, data security faces huge challenges. Since the centralized server becomes a single attack target, it is easy to be attacked by hackers, resulting in the leakage of sensitive information in the bidding process; on the other hand, the risk of data tampering is extremely high. Whether it is internal authorized personnel for personal gain or external lawless elements through illegal means, it is possible to modify the bidding data, which undermines the fairness and legality of the bidding and disrupts the normal market competition order;

[0003] At the same time, the traditional bidding process lacks information transparency, and information is often limited to a few key participants. It is difficult for bidders and the general public to obtain comprehensive, accurate and timely information, which can easily lead to widespread doubts about the fairness of the bidding. Therefore, we propose a bidding data management method and system based on blockchain. Summary of the invention

[0004] The purpose of the present invention is to propose a blockchain-based bidding data management method and system to address the problems of low data security and insufficient information transparency in the traditional bidding data management mode in the background technology.

[0005] Aspect 1: This application provides a bidding data management method based on blockchain, comprising the following steps:

[0006] Optionally, the bidding data is encrypted and stored in multiple nodes using blockchain distributed ledger technology, and the data is encrypted using an asymmetric encryption algorithm and a hash algorithm to form a chain structure;

[0007] Build a P2P network to enable the nodes to communicate directly and share data, and use the PBFT consensus algorithm to ensure data consistency;

[0008] Automatically execute bid opening and evaluation operations through Ethereum-based smart contracts embedded with bidding rules and processes, and conduct fair evaluation based on preset standards;

[0009] Each bidding party operates through the corresponding user interface, and the public and bidders query project information through the blockchain browser developed based on front-end technology;

[0010] The bidding data is backed up.

[0011] Optionally, the asymmetric encryption algorithm adopts the RSA algorithm. When encrypting different types of data files, byte stream encryption and block encryption adaptation strategies are respectively adopted for text, picture, and video files, wherein the encryption process formula is expressed as follows: ;

[0012] The decryption process formula is: ;

[0013] in, Represents the encrypted ciphertext, Represents the original message, represents the encryption exponent of the public key, represents the modulus of the public key, represents the decryption exponent of the private key;

[0014] The hash algorithm uses SHA-256, and the data block hash value generation formula is:

[0015] Among them, the blockchain chain structure formula is:

[0016] in, Represents a hash value, Represents the content of the original data block, and || represents the connection operation;

[0017] When the hash algorithm generates the hash value of the data block, the key data fields are weighted and calculated according to different weight coefficients, including the timestamp, data source identifier, and data content summary. The formula is:

[0018]

[0019] in, is the weighted hash value, , , They are the corresponding field hash values, , , are weights and sum to 1.

[0020] Optionally, the PBFT consensus algorithm uses the HMAC-SHA256 algorithm to calculate the message authentication code in node communication. The sending node uses the shared key to calculate and append the MAC value, which is verified by the receiving node. The formula is: ,in, is the shared key, For messages, in the PBFT consensus algorithm, it is assumed that there are nodes, of which are Byzantine nodes and , including the following steps:

[0021] Pre-preparation phase: The master node packages the received transaction requests into pre-preparation messages Send to other nodes, where Indicates the view number, Indicates the message sequence number. Represents the summary of the transaction request, Indicates the specific content of the transaction request;

[0022] Preparation phase: After receiving the pre-preparation message, the other nodes verify the legitimacy and signature of the message. If the verification is successful, the preparation message is sent to the other nodes. ,in Indicates the number of the sending node. When the node receives at least When there is a prepare message with the same sequence number and view number, it enters the confirmation phase;

[0023] Confirmation phase: the node sends a confirmation message to the other nodes , when the node receives at least When a confirmation message with the same sequence number and view number is received, the transaction is considered to have reached consensus and is recorded on the blockchain.

[0024] Optionally, when the smart contract is evaluating bids, the evaluation criteria include quantitative indicators and non-quantitative indicators, the quantitative indicators include price, construction period, and technical parameters, and the non-quantitative indicators include corporate reputation and project experience;

[0025] The quantitative indicators are scored using a linear weighted method, and the non-quantitative indicators are comprehensively evaluated and scored using a preset rating scale and an expert evaluation weight system. The expert evaluation weight system determines the weight value of each expert based on the expert's professional field, industry experience, and historical evaluation accuracy, and calculates the non-quantitative indicator score using a weighted average method. At the same time, the judgment matrix is ​​constructed using the hierarchical analysis method and the weight vector of each expert is obtained by solving the eigenvector method. , where n is the number of experts, and the non-quantitative indicator scoring formula is: ,in, Represents different non-quantitative indicators, Indicates the score corresponding to the expert evaluation level of this indicator.

[0026] Optionally, the blockchain browser is developed based on HTML, CSS and JavaScript, and acquires and displays data through an interactive interface with the blockchain node. When displaying data, for the time series analysis of the data, the moving average method is used for data smoothing. Assuming that the original data sequence is , the window size is , then the moving average sequence is .

[0027] Second aspect: The present application provides a bidding data management system based on blockchain, characterized in that it includes: a data storage module for storing various types of bidding data, and encrypting the bidding data by an asymmetric encryption algorithm and a hash algorithm;

[0028] A network communication module is used to enable the nodes to communicate and share data, and ensure data consistency through the PBFT consensus algorithm;

[0029] A smart contract module, used to realize the automated and fair execution of bidding, wherein the smart contract module includes a smart contract embedded with bidding rules and procedures;

[0030] User interface module, used to provide a user interface for each bidding party;

[0031] Data backup and recovery module, used to regularly back up blockchain bidding data, and adopts a combination of incremental and full strategies to store data in secure and independent media

[0032] Optionally, the data backup and recovery module uses distributed storage and Reed-Solomon encoding technology. When encoding data, the Reed-Solomon encoding assumes that the original data is , the encoded data is , generating polynomials according to the encoding parameters , the encoded data is obtained through polynomial operation The encoding process follows the standard algorithm flow of Reed-Solomon encoding.

[0033] Optionally, the network communication module adopts PKI technology identity authentication when a node joins. The new node applies for a digital certificate and is connected after verification by a certification body. Permissions are assigned according to roles. The verification process of the digital certificate follows the X.509 certificate standard format and verification process to ensure the authenticity and validity of the certificate and protect the security of network communications.

[0034] Optionally, during the operation of the smart contract module, contract vulnerabilities are detected by combining static analysis tools with dynamic monitoring. The static analysis tool analyzes the syntax, semantics and logical structure of the smart contract code, and performs detection based on known vulnerability patterns and security rules. The dynamic monitoring collects key data of contract execution in real time in the contract running environment, including function call parameters and variable value changes, and uses anomaly detection algorithms to determine whether there is abnormal behavior in the contract operation. If there are vulnerabilities or anomalies, an early warning message is issued and a repair strategy is provided. The early warning information and repair strategy are displayed through the user interface module.

[0035] In summary, the present application includes at least one of the following beneficial technical effects:

[0036] 1. The present invention uses the distributed ledger technology of blockchain so that the bidding data is no longer stored in a single centralized server, but is encrypted and stored on multiple nodes of the blockchain. Each data block forms an unalterable chain structure through a hash algorithm, which improves the integrity and authenticity of the data. At the same time, an asymmetric encryption algorithm is used to encrypt the data, ensuring the traceability and non-repudiation of the data source, effectively preventing the data from being stolen or tampered with during transmission and storage, and further enhancing the confidentiality and security of the data.

[0037] 2. The blockchain-based bidding data management system enables all data in the bidding process to be clearly viewed and traced by authorized parties. Each link of the bidding process leaves an unalterable record on the blockchain. Bidders and the public can query the detailed information and progress of the bidding project through the blockchain browser, thereby achieving effective supervision and verification of the bid evaluation process and bid results, and improving the transparency and fairness of the bidding process;

[0038] 3. The use of smart contracts realizes the automated execution of the bidding process, reduces the factors of human intervention, and improves the efficiency and fairness of bidding. Since the execution results of smart contracts are deterministic and irreversible, once the preset conditions are met, the contract will automatically execute the corresponding operations without relying on the trust and intervention of a third party, reducing transaction costs and risks, and further improving the transparency and credibility of the bidding process.

[0039] 4. The P2P-based network architecture enables each node to communicate and share data directly, avoiding the risk of single point failure of centralized servers and ensuring the availability and integrity of bidding data. At the same time, combined with the PBFT algorithm, it ensures the consistency of data recognition by each node. Even in the presence of a certain number of Byzantine nodes, a correct consensus can still be reached to ensure the stable operation of the blockchain network and the security of data. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flowchart of a bidding data management method based on blockchain is given in the present invention;

[0041] Figure 2 This is a principle block diagram of a blockchain-based bidding data management system of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Example:

[0044] The present invention proposes a bidding data management method based on blockchain, such as Figure 1 As shown, the following steps are included:

[0045] 1. System Construction

[0046] Choose Ethereum as the blockchain platform;

[0047] Data storage: Distributed ledger technology based on blockchain is used to store large file data such as bidding documents and project documents. A hash algorithm (such as SHA-256) is used to generate a file hash value to identify file integrity and storage location. The hash algorithm uses SHA-256, and the data block hash value generation formula is:

[0048] Among them, the blockchain chain structure formula is:

[0049] in, Represents a hash value, Represents the content of the original data block, and || represents the connection operation;

[0050] When the hash algorithm generates the hash value of a data block, the key data fields are weighted according to different weight coefficients, including timestamp, data source identifier, and data content summary. The formula is:

[0051]

[0052] in, is the weighted hash value, , , They are the corresponding field hash values, , , is the weight and the sum is 1;

[0053] Network communication: The network communication module is built based on the P2P network protocol, and the PBFT algorithm is used to ensure data consistency and network stability between nodes. The PBFT consensus algorithm uses the HMAC-SHA256 algorithm to calculate the message authentication code in node communication. The sending node uses the shared key to calculate and append the MAC value, and the receiving node verifies it. The formula is: ,in, is the shared key, For messages, in the PBFT consensus algorithm, it is assumed that there are nodes, of which are Byzantine nodes and , including the following steps:

[0054] Pre-preparation phase: The master node packages the received transaction requests into pre-preparation messages Send to other nodes, where Indicates the view number, Indicates the message sequence number. Represents the summary of the transaction request, Indicates the specific content of the transaction request;

[0055] Preparation phase: After receiving the pre-preparation message, other nodes verify the legitimacy and signature of the message. If the verification is successful, they send the preparation message to other nodes. ,in Indicates the number of the sending node. When the node receives at least When there is a prepare message with the same sequence number and view number, it enters the confirmation phase;

[0056] Confirmation phase: The node sends a confirmation message to other nodes , when a node receives at least When a confirmation message with the same sequence number and view number is received, the transaction is considered to have reached consensus and is recorded on the blockchain;

[0057] Smart contracts: Use Solidity language to write smart contracts to automate the bidding process, including the release of bidding notices, deadlines for submission of bidding documents, setting of bid evaluation criteria, and bid opening and evaluation processes;

[0058] User interface: Each bidding party operates through the corresponding user interface, and the public and bidders query project information through the blockchain browser developed based on front-end technology;

[0059] The blockchain browser is developed based on HTML, CSS and JavaScript. It obtains and displays data through the interactive interface with the blockchain node. When displaying data, the moving average method is used to smooth the data for the time series analysis of the data. Assuming that the original data sequence is , the window size is , then the moving average sequence is

[0060] 2. System initialization and node configuration

[0061] First, the government bidding agency acts as the main node to create the initial information of the bidding project, including the project name, bidding scope, technical requirements, budget amount, and bid opening time, and publishes the initial information to the blockchain through a smart contract. At the same time, it generates a unique project identifier and blockchain address for subsequent bidding companies and other relevant parties to query and participate.

[0062] Secondly, identity authentication and authorization configuration are performed on each node participating in the network. PKI technology based on digital certificates is used to issue digital certificates to each node to ensure the legitimacy and security of the node. According to the role of the node, the corresponding operation authority and data access scope are assigned to it. The bidder node can only submit the bid document within the specified bidding time, while the bid evaluation expert node can access the bid document and perform bid evaluation and scoring operations after the bid opening, but cannot modify the basic information of the bidding project and the content of the bid document;

[0063] 3. Execution of the Bidding Process

[0064] Tender announcement release: The tenderer releases the tender announcement on the blockchain through the user interface provided by the user interface module. The tender announcement includes the specific requirements of the project, the format of the tender document, the evaluation criteria, and the tender deadline. The tender announcement information is encrypted and stored on multiple nodes of the blockchain, and a unique hash value is generated through a hash algorithm to ensure the integrity and immutability of the information;

[0065] At the same time, the release information of the tender notice will be automatically synchronized to the blockchain browser, making it convenient for bidding companies and the public to view;

[0066] Submission of bidding documents: After obtaining the bidding announcement information, the bidding enterprise shall prepare the bidding documents as required, and use the encryption tools provided by the system to encrypt and digitally sign the bidding documents using an asymmetric encryption algorithm (RSA algorithm). The asymmetric encryption algorithm uses the RSA algorithm. When encrypting different types of data files, the byte stream encryption and block encryption adaptation strategies are used for text, image, and video files respectively. The encryption process formula is expressed as follows: ;

[0067] The decryption process formula is: ;

[0068] in, Represents the encrypted ciphertext, Represents the original message, represents the encryption exponent of the public key, represents the modulus of the public key, Indicates the decryption index of the private key. The enterprise's quotation information is encrypted using the private key to ensure that only the enterprise can decrypt and view it. At the same time, a digital signature is generated for the entire bidding document to prevent the document from being tampered with during transmission and storage;

[0069] Before the bidding deadline, the bidding enterprise uploads the encrypted bidding documents to the blockchain network through the user interface module. The documents are divided into multiple data blocks and stored on different nodes. Each data block contains the hash value of the previous data block, forming a chain structure to further enhance the security and integrity of the data. At the same time, the submission operation records of the bidding enterprise are also recorded on the blockchain, including the submission time and file hash value, for subsequent tracing and verification;

[0070] Bid opening and evaluation: When the bid opening time arrives, the smart contract automatically executes the bid opening operation and decrypts and verifies all bid documents submitted on time according to the preset bid opening rules. The bid opening rules are specified according to the specific project requirements.

[0071] First, check whether the digital signature of the bidding document is valid to ensure that the document has not been tampered with and is from a legitimate bidding company. Then, decrypt the key information in the bidding document, including the quotation and construction period, and display the key information on the evaluation expert's interface, but do not display the name of the bidding company, to ensure the fairness and objectivity of the evaluation process.

[0072] Secondly, the bid evaluation experts log in to the system through the user interface module to review and score the bid documents. For quantitative indicators, the linear weighted method is used for scoring. Quantitative indicators include price, construction period, and technical parameters. For non-quantitative indicators, the expert evaluation weight system is used for comprehensive evaluation and scoring. The expert evaluation weight system determines the weight value of each expert based on the expert's professional field, industry experience, and historical evaluation accuracy, and calculates the non-quantitative indicator score through the weighted average method. At the same time, the hierarchical analysis method is used to construct the judgment matrix and the eigenvector method is used to solve the weight vector of each expert. , where n is the number of experts, and the non-quantitative indicator scoring formula is: ,in, Represents different non-quantitative indicators, Indicates the score corresponding to the expert evaluation level of the indicator;

[0073] During the bid evaluation process, every operation record of the experts, including the time of viewing the bid documents, scoring, and comment writing, is recorded in real time on the blockchain, and the operation records are signed through electronic signature technology to ensure the traceability and non-repudiation of the bid evaluation process; at the same time, the system uses real-time data synchronization technology to ensure that the bid document data viewed by the bid evaluation experts is consistent with the data stored on the blockchain in real time, avoiding bid evaluation deviations caused by inconsistent data;

[0074] Public announcement of winning bid results: The smart contract automatically calculates the comprehensive score of each bidding enterprise based on the scoring results of the bid evaluation experts, and determines the winning enterprise according to the score. The winning bid results are announced on the blockchain, including the name of the winning enterprise, the score, key information of the bidding documents, etc. At the same time, they are open to the public for inquiry through the blockchain browser and are subject to social supervision;

[0075] During the publicity period, any bidding enterprise or the public who has objections to the bid results can query the bid evaluation records and data through the blockchain browser, including the original content of the bidding documents, the basis and process of expert scoring. If there is conclusive evidence of violations, they can file a complaint with the regulatory agency. The regulatory agency has the right to conduct a comprehensive review and investigation of the entire bidding process through the system's regulatory interface, and use the traceability of blockchain and the immutability of data to quickly identify the problem and take appropriate measures to deal with it, so as to ensure the fairness and legality of the bidding results.

[0076] 4. Data backup and recovery

[0077] Regular backup strategy: The system's data backup and recovery module adopts a regular backup strategy, which performs a full backup of the bidding data on the blockchain every morning, and performs incremental backup of the newly added transaction data every 4 hours during the day. The backup data is stored in an independent and secure storage medium, including a local redundant hard disk array and a remote cloud storage service to prevent the loss of backup data;

[0078] During the backup process, Reed-Solomon coding technology is used to perform redundancy processing on the backup data. The coding parameters are dynamically adjusted according to the importance of the data and the network status. When Reed-Solomon coding is used to encode data, it is assumed that the original data is , the encoded data is , generating polynomials according to the encoding parameters , the encoded data is obtained through polynomial operation The encoding process follows the standard algorithm flow of Reed-Solomon encoding. For key bidding document data, a higher redundancy setting is used to ensure that the original data can be fully restored through redundant data when some storage nodes fail. At the same time, the backup data is encrypted and integrity checked, and a hash value of the data is generated after the backup is completed to verify the integrity of the backup data and ensure the security and reliability of the backup data.

[0079] Data recovery operation: When blockchain data is lost or damaged, first determine the data range and time point that needs to be restored based on the data loss or damage situation, then obtain the corresponding backup data from the backup storage medium, use the Reed-Solomon encoding decoding algorithm to process the redundant data, restore the original data, and verify the integrity of the restored data through the hash value;

[0080] The recovered data is re-uploaded to the blockchain network, and the consensus algorithm (PBFT algorithm) is used to ensure that each node recognizes the consistency of the recovered data. The PBFT consensus algorithm uses the HMAC-SHA256 algorithm to calculate the message authentication code in node communication. The sending node uses the shared key to calculate and append the MAC value, and the receiving node verifies it. The formula is: ,in, is the shared key, For messages, in the PBFT consensus algorithm, it is assumed that there are nodes, of which are Byzantine nodes and , including the following steps:

[0081] Pre-preparation phase: The master node packages the received transaction requests into pre-preparation messages Send to other nodes, where Indicates the view number, Indicates the message sequence number. Represents the summary of the transaction request, Indicates the specific content of the transaction request;

[0082] Preparation phase: After receiving the pre-preparation message, other nodes verify the legitimacy and signature of the message. If the verification is successful, they send the preparation message to other nodes. ,in Indicates the number of the sending node. When the node receives at least When there is a prepare message with the same sequence number and view number, it enters the confirmation phase;

[0083] Confirmation phase: The node sends a confirmation message to other nodes , when a node receives at least When a confirmation message with the same sequence number and view number is received, the transaction is considered to have reached consensus and is recorded on the blockchain;

[0084] Enable the blockchain network to return to normal operation, ensure the availability and integrity of the bidding data, minimize the impact of data loss on the bidding work, and ensure the smooth progress of the bidding project;

[0085] In the second aspect, this application provides a bidding data management system based on blockchain, such as Figure 2As shown, it includes a data storage module, a network communication module, a smart contract module, a user interface module, and a data backup and recovery module;

[0086] The data storage module is used to store various bidding data and encrypt the bidding data through asymmetric encryption algorithm and hash algorithm;

[0087] The network communication module is used to enable nodes to communicate and share data, and ensure data consistency through the PBFT consensus algorithm. The network communication module uses PKI technology identity authentication when a node joins. The new node applies for a digital certificate and is connected after verification by the certification body. Permissions are assigned based on roles. The verification process of the digital certificate follows the X.509 certificate standard format and verification process to ensure the authenticity and validity of the certificate and protect network communication security.

[0088] The smart contract module is used to realize the automated and fair execution of bidding. The smart contract module includes a smart contract embedded with bidding rules and processes. During the operation of the smart contract module, contract vulnerabilities are detected through static analysis tools combined with dynamic monitoring. Static analysis tools analyze the syntax, semantics and logical structure of smart contract codes, and detect them according to known vulnerability patterns and security rules. Dynamic monitoring collects key data of contract execution in real time in the contract operation environment, including function call parameters and variable value changes, and uses anomaly detection algorithms to determine whether there are abnormal behaviors in the contract operation. If there are vulnerabilities or anomalies, early warning information is issued and repair strategies are provided. The early warning information and repair strategies are displayed through the user interface module;

[0089] The user interface module is used to provide a user interface for each bidding party;

[0090] The data backup and recovery module is used to regularly back up blockchain bidding data, and adopts a combination of incremental and full strategies to store data in secure and independent media. The data backup and recovery module uses distributed storage and Reed-Solomon encoding technology. When Reed-Solomon encoding is used to encode data, it is assumed that the original data is , the encoded data is , generating polynomials according to the encoding parameters , the encoded data is obtained through polynomial operation The encoding process follows the standard algorithm flow of Reed-Solomon encoding.

[0091] The above specific embodiments are only several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant inspirations of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A bidding data management method based on blockchain, characterized in that: The following steps are involved: The bidding data is encrypted and stored in multiple nodes using blockchain distributed ledger technology, and the data is encrypted using asymmetric encryption algorithms and hash algorithms to form a chain structure; Build a P2P network to enable the nodes to communicate directly and share data, and use the PBFT consensus algorithm to ensure data consistency; Automatically execute bid opening and evaluation operations through Ethereum-based smart contracts embedded with bidding rules and processes, and conduct fair evaluation based on preset standards; Each bidding party operates through the corresponding user interface, and the public and bidders query project information through the blockchain browser developed based on front-end technology; The bidding data is backed up.

2. According to a blockchain-based bidding data management method according to claim 1, it is characterized in that: The asymmetric encryption algorithm adopts the RSA algorithm. When encrypting different types of data files, the byte stream encryption and block encryption adaptation strategies are adopted for text, picture, and video files respectively. The encryption process formula is expressed as follows: ; The decryption process formula is: ; in, Represents the encrypted ciphertext, Represents the original message, represents the encryption exponent of the public key, represents the modulus of the public key, represents the decryption exponent of the private key; The hash algorithm uses SHA-256, and the data block hash value generation formula is: Among them, the blockchain chain structure formula is: in, Represents a hash value, Represents the content of the original data block, and || represents the connection operation; When the hash algorithm generates the hash value of the data block, the key data fields are weighted and calculated according to different weight coefficients, including the timestamp, data source identifier, and data content summary. The formula is: in, is the weighted hash value, , , They are the corresponding field hash values, , , are weights and sum to 1.

3. According to a blockchain-based bidding data management method according to claim 1, it is characterized in that: The PBFT consensus algorithm uses the HMAC-SHA256 algorithm to calculate the message authentication code in node communication. The sending node uses the shared key to calculate and append the MAC value, which is verified by the receiving node. The formula is: ,in, is the shared key, For messages, in the PBFT consensus algorithm, it is assumed that there are nodes, of which are Byzantine nodes and , including the following steps: Pre-preparation phase: The master node packages the received transaction requests into pre-preparation messages Send to other nodes, where Indicates the view number, Indicates the message sequence number. Represents the summary of the transaction request, Indicates the specific content of the transaction request; Preparation phase: After receiving the pre-preparation message, the other nodes verify the legitimacy and signature of the message. If the verification is successful, the preparation message is sent to the other nodes. ,in Indicates the number of the sending node. When the node receives at least When there is a prepare message with the same sequence number and view number, it enters the confirmation phase; Confirmation phase: the node sends a confirmation message to the other nodes , when the node receives at least When a confirmation message with the same sequence number and view number is received, the transaction is considered to have reached consensus and is recorded on the blockchain.

4. According to a blockchain-based bidding data management method according to claim 1, it is characterized in that: When the smart contract is evaluating bids, the evaluation criteria include quantitative indicators and non-quantitative indicators. The quantitative indicators include price, construction period, and technical parameters, and the non-quantitative indicators include corporate reputation and project experience. The quantitative indicators are scored using a linear weighted method, and the non-quantitative indicators are comprehensively evaluated and scored using a preset rating scale and an expert evaluation weight system. The expert evaluation weight system determines the weight value of each expert based on the expert's professional field, industry experience, and historical evaluation accuracy, and calculates the non-quantitative indicator score using a weighted average method. At the same time, the judgment matrix is ​​constructed using the hierarchical analysis method and the weight vector of each expert is obtained by solving the eigenvector method. , where n is the number of experts, and the non-quantitative indicator scoring formula is: ,in, Represents different non-quantitative indicators, Indicates the score corresponding to the expert evaluation level of this indicator.

5. According to a blockchain-based bidding data management method according to claim 1, it is characterized in that: The blockchain browser is developed based on HTML, CSS and JavaScript. It obtains and displays data through the interactive interface with the blockchain node. When displaying data, the moving average method is used to smooth the data for the time series analysis of the data. Assuming that the original data sequence is , the window size is , then the moving average sequence is .

6. A bidding data management system based on blockchain, characterized in that: include: A data storage module, used to store various bidding data, and encrypt the bidding data by using an asymmetric encryption algorithm and a hash algorithm; A network communication module is used to enable the nodes to communicate and share data, and ensure data consistency through the PBFT consensus algorithm; A smart contract module, used to realize the automated and fair execution of bidding, wherein the smart contract module includes a smart contract embedded with bidding rules and procedures; User interface module, used to provide a user interface for each bidding party; The data backup and recovery module is used to regularly back up blockchain bidding data, and adopts a combination of incremental and full strategies to store the data in secure and independent media.

7. A blockchain-based bidding data management system according to claim 6, characterized in that: The data backup and recovery module uses distributed storage and Reed-Solomon coding technology. When encoding data, the Reed-Solomon coding assumes that the original data is , the encoded data is , generating polynomials according to the encoding parameters , the encoded data is obtained through polynomial operation The encoding process follows the standard algorithm flow of Reed-Solomon encoding.

8. According to a blockchain-based bidding data management method and system according to claim 6, it is characterized in that: The network communication module uses PKI technology for identity authentication when a node joins. The new node applies for a digital certificate and is connected after verification by the certification body. Permissions are assigned according to roles. The verification process of the digital certificate follows the X.509 certificate standard format and verification process to ensure the authenticity and validity of the certificate and protect network communication security.

9. A blockchain-based bidding data management system according to claim 6, characterized in that: During the operation of the smart contract module, contract vulnerabilities are detected by combining static analysis tools with dynamic monitoring. The static analysis tool analyzes the syntax, semantics and logical structure of the smart contract code, and detects according to known vulnerability patterns and security rules. The dynamic monitoring collects key data of contract execution in real time in the contract running environment, including function call parameters and variable value changes, and uses anomaly detection algorithms to determine whether there is abnormal behavior in the contract operation. If there are vulnerabilities or anomalies, early warning information is issued and repair strategies are provided. The early warning information and repair strategies are displayed through the user interface module.

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