Decoration contract risk assessment and encryption management method and system based on block chain

Abstract

The invention discloses a decoration contract risk assessment and encryption management method and system based on a block chain, and belongs to the field of data management. The method comprises the following steps: receiving a first decoration contract sent by a user, and determining whether the first decoration contract has a contract risk; if yes, determining a risk type and a modification suggestion; if the modified second decoration contract is received, transmitting the second decoration contract to the block chain platform; contract information of the second decoration contract is determined and encrypted, and ciphertext information is obtained and transmitted to the block chain platform; and generating a first zero-knowledge proof, and transmitting the first zero-knowledge proof to the block chain platform. The automatic process of the scheme can reduce manual intervention and improve the speed and efficiency of contract processing. Contracts and related information are stored on the block chain, so that the data are ensured not to be tampered, and the trust is enhanced. Contract information is encrypted, sensitive information is protected, and it can be ensured that only an authorization party can access. And the zero-knowledge proof is generated, so that the privacy of data sharing can be improved.

Description

Technical Field

[0001] The present application relates to the field of data management technology, and in particular to a blockchain-based renovation contract risk assessment and encryption management method and system. Background Art

[0002] As the decoration market continues to expand, the content of contracts becomes more complex and diverse, and potential legal and economic risks also increase. Through risk assessment, potential risks can be identified and avoided in advance to protect the rights and interests of both parties. At the same time, encryption management technology is used to encrypt contract information to ensure the security and integrity of information during transmission and storage, prevent the leakage of sensitive information, and provide solid protection for the smooth progress of decoration projects.

[0003] Nowadays, risk assessment of renovation contracts is usually conducted manually. Professional teams review the contract terms one by one, identify potential legal and economic risks, and give assessment opinions. Then traditional encryption algorithms (such as AES and RSA) are used to encrypt the contract documents to ensure that the documents are not accessed by unauthorized persons during transmission and storage. This encryption method requires both parties to share a key in order to decrypt and view the contract content.

[0004] However, manually assessing contract risks requires a lot of human resources and time, which is inefficient, especially when faced with a large number of contracts. Although traditional encryption algorithms can protect contract documents from unauthorized access, the management and distribution of keys is a potential security risk. If the key is leaked or lost, the encrypted file will be at risk of being decrypted. Summary of the invention

[0005] The embodiment of the present application provides a blockchain-based renovation contract risk assessment and encryption management method and system, which solves the problem that the manual assessment of contract risks in the prior art requires a lot of human resources and time, especially when facing a large number of contracts, which is inefficient. Although traditional encryption algorithms can protect contract documents from unauthorized access, the management and distribution of keys is a potential security risk. If the key is leaked or lost, the encrypted file will face the risk of being decrypted.

[0006] In the first aspect, the embodiment of the present application provides a renovation contract risk assessment and encryption management method based on blockchain, the method comprising: receiving a first decoration contract sent by a user, inputting the first decoration contract into a preset risk assessment model to obtain a risk score, and determining whether there is a contract risk according to the risk score and a preset risk score threshold; If there is a contract risk, the risk type and modification suggestions are determined through a preset risk assessment model, and the risk type and modification suggestions are sent to the control center; If the modified second decoration contract sent by the control center is received, the second decoration contract is transmitted to the blockchain platform; Input the second renovation contract into a preset contract information extraction model to obtain contract information, encrypt the contract information using a preset attribute encryption algorithm to obtain ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform; Generate a first zero-knowledge proof of the contract information and the ciphertext information, and transmit the first zero-knowledge proof to the blockchain platform.

[0007] Furthermore, after transmitting the second renovation contract to the blockchain platform, the method further includes: Continuously monitor the contract execution data of the second renovation contract through the preset smart contract; If a key node is read, the node type of the key node is obtained, a target operation is determined according to the node type and a preset operation rule, and the target operation is executed.

[0008] Furthermore, after determining the target operation according to the node type and the preset operation rule and executing the target operation, the method further includes: Continuously monitor the transaction status corresponding to each key node through a preset smart contract. If the transaction status is monitored to be in a transaction completion state, obtain transaction identification information, status update information and attribute information; A second zero-knowledge proof corresponding to each key node is generated according to the transaction identification information, status update information and attribute information through a preset smart contract, and the second zero-knowledge proof is transmitted to the blockchain platform.

[0009] Furthermore, the contract information is encrypted by a preset attribute encryption algorithm to obtain ciphertext information of the contract information, including: Obtaining a preset access strategy and initial state information of the second renovation contract, and determining a target access strategy according to the initial state information and the preset access strategy; wherein the preset access strategy includes strategy version information; Generate a first public parameter, and generate an encryption key according to the first public parameter, the target access policy, and the initial state information; The contract information is encrypted according to the encryption key to obtain ciphertext information, and the policy version information is embedded in the ciphertext information.

[0010] Furthermore, after determining the target operation according to the node type and the preset operation rule and executing the target operation, the method further includes: The execution status information of each key node is monitored through a preset smart contract, and the target access strategy and policy version information of each key node are determined based on the execution status information and the preset access strategy.

[0011] Furthermore, after determining the target access strategy and strategy version information of each key node, the method further includes: Regenerate the first public parameter, and regenerate the encryption key of each key node according to the first public parameter, the target access policy of each key node, and the execution status information; The contract information of each key node is encrypted according to the encryption key to obtain the ciphertext information of the contract information of each key node, and the policy version information of each key node is embedded in the ciphertext information.

[0012] Furthermore, after generating the first zero-knowledge proof of the contract information and the ciphertext information and transmitting the first zero-knowledge proof to the blockchain platform, the method further includes: Receive a data acquisition request from a client, determine user attribute information according to the data acquisition request, generate zero-knowledge proof challenge information, and send the zero-knowledge proof challenge information to the client; Receiving a third zero-knowledge proof generated by the client according to the zero-knowledge proof challenge information, determining a target key node and a target access policy according to the data acquisition request, and acquiring a second zero-knowledge proof corresponding to the target key node; Verifying whether the third zero-knowledge proof meets a preset challenge condition according to the first zero-knowledge proof and the second zero-knowledge proof; If the preset challenge conditions are met, a second public parameter is generated, a decryption key is generated according to the user attribute information, the target access policy, the execution status information and the second public parameter, and the decryption key is sent to the client.

[0013] Furthermore, the training steps of the preset risk assessment model include: Acquire historical renovation contracts, annotate risk score labels on the historical renovation contracts, and create a first data set based on the historical renovation contracts and the risk score labels; Acquire historical risky renovation contracts, mark the risk type labels and modification suggestion labels of the historical risky renovation contracts, and create a second data set according to the historical risky renovation contracts, the risk type labels, and the modification suggestion labels; Constructing a risk assessment model, and training the risk assessment model according to the first data set and the second data set until the risk assessment model reaches a preset risk assessment model standard.

[0014] Furthermore, the training steps of the preset contract information extraction model include: Acquire historical renovation contracts, mark contract information tags of the historical renovation contracts, and construct a third data set based on the historical renovation contracts and the contract information tags; A contract information extraction model is constructed, and the contract information extraction model is trained according to the third data set until the contract information extraction model reaches a preset contract information extraction model training standard.

[0015] According to the second aspect of the present application, a blockchain-based renovation contract risk assessment and encryption management system is provided, the system comprising: A risk determination module, configured to receive a first decoration contract sent by a user, input the first decoration contract into a preset risk assessment model to obtain a risk score, and determine whether there is a contract risk according to the risk score and a preset risk score threshold; An assessment module, for determining the risk type and modification suggestions through a preset risk assessment model if there is a contract risk, and sending the risk type and modification suggestions to a control center; A transmission module, configured to transmit the second decoration contract to the blockchain platform if the modified second decoration contract sent by the control center is received; An encryption module, used to input the second decoration contract into a preset contract information extraction model to obtain contract information, encrypt the contract information through a preset attribute encryption algorithm to obtain ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform; The zero-knowledge proof generation module is used to generate a first zero-knowledge proof of the contract information and the ciphertext information, and transmit the first zero-knowledge proof to the blockchain platform.

[0016] In an embodiment of the present application, a first decoration contract sent by a user is received, the first decoration contract is input into a preset risk assessment model to obtain a risk score, and whether there is a contract risk is determined according to the risk score and the preset risk score threshold; if there is a contract risk, the risk type and modification suggestions are determined by the preset risk assessment model, and the risk type and modification suggestions are sent to the control center; if the modified second decoration contract sent by the control center is received, the second decoration contract is transmitted to the blockchain platform; the second decoration contract is input into a preset contract information extraction model to obtain contract information, and the contract information is encrypted by a preset attribute encryption algorithm to obtain ciphertext information of the contract information, and the ciphertext information is transmitted to the blockchain platform; the first zero-knowledge proof of the contract information and the ciphertext information is generated, and the first zero-knowledge proof is transmitted to the blockchain platform. Through the above-mentioned blockchain-based decoration contract risk assessment and encryption management method, the automated process can reduce manual intervention and improve the speed and efficiency of contract processing. The contract and related information are stored on the blockchain to ensure the immutability of the data and enhance trust. Encrypting the contract information and protecting sensitive information can ensure that only authorized parties can access it. Generating zero-knowledge proofs allows the validity of a contract to be proven without revealing the specific contract content, which can improve the privacy of data sharing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flowchart of the renovation contract risk assessment and encryption management method based on blockchain provided in Example 1 of the present application; Figure 2 This is a flowchart of a renovation contract risk assessment and encryption management method based on blockchain provided in Example 2 of the present application; Figure 3 This is a flowchart of a renovation contract risk assessment and encryption management method based on blockchain provided in Example 3 of the present application; Figure 4 This is a structural diagram of the blockchain-based renovation contract risk assessment and encryption management system provided in Example 4 of the present application. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present application clearer, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. It is understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for the convenience of description, only part of the present application is shown in the accompanying drawings, but not all of the content. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow chart describes each operation (or step) as a sequential process, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but it can also have additional steps not included in the accompanying drawings. The process can correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0020] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0021] The following, in conjunction with the accompanying drawings, describes in detail the blockchain-based renovation contract risk assessment and encryption management method provided by the embodiment of the present application through specific embodiments and their application scenarios.

[0022] Embodiment 1 Figure 1 This is a flowchart of the blockchain-based renovation contract risk assessment and encryption management method provided in Example 1 of this application. Figure 1 As shown, the specific steps include: S101, receiving a first decoration contract sent by a user, inputting the first decoration contract into a preset risk assessment model to obtain a risk score, and determining whether there is a contract risk based on the risk score and a preset risk score threshold.

[0023] First of all, the usage scenario of this solution can be the scenario of risk assessment and encryption of decoration contracts.

[0024] Based on the above usage scenarios, it can be understood that the executor of this application can be the decoration contract risk assessment and encryption management system, and no excessive restrictions are made here.

[0025] The first decoration contract may be a contract text submitted by the user for the first time, and may include specific requirements, terms and conditions of the decoration project.

[0026] A preset risk assessment model can be an algorithm or machine learning model that is trained to identify potential risks in a contract.

[0027] The risk score can be a numerical value output by the risk assessment model, which indicates the overall risk level of the contract.

[0028] The preset risk score threshold may be a pre-set benchmark value used to determine the level of the risk score.

[0029] Users can upload the first renovation contract through the system interface (such as a website or application). The system provides an upload function and supports multiple file formats (such as PDF, Word, etc.). The system extracts text information from the uploaded contract, which can use OCR (optical character recognition) technology (if it is in image format) or text parsing technology (if it is in document format). The extracted contract text is formatted into the input format required by the risk assessment model, ensuring that all key information (such as terms, amounts, time, etc.) is included. The prepared contract information is then input into the preset risk assessment model. The model can analyze the content of the contract and identify potential risk factors. Then a risk score is output, which can be a numerical value that represents the overall risk level of the contract. The generated risk score is compared with the preset risk score threshold. The threshold can be set based on company policy or historical data. If the risk score is higher than the threshold, the system determines that the contract is risky.

[0030] S102: If there is a contract risk, the risk type and modification suggestions are determined through a preset risk assessment model, and the risk type and modification suggestions are sent to the control center.

[0031] Risk types can refer to specific risk factors identified in the contract. For example, they can include legal risks: such as the terms of the contract not complying with relevant laws and regulations. Financial risks: such as unreasonable payment terms, leading to potential financial losses. Time risks: such as unclear completion time of the project, which may lead to delays. Performance risks: such as the risk that one party to the contract fails to perform its obligations.

[0032] The modification suggestions can be specific suggestions for improving the contract content to reduce the identified risks. They can include legal risks: it is recommended to consult a legal advisor to modify the clauses that do not comply with the regulations. Financial risks: it is recommended to re-evaluate the payment terms and add a deposit clause. Time risks: it is recommended to clarify the project time nodes and add extension clauses. Performance risks: it is recommended to add a breach of contract liability clause to ensure the rights and interests of both parties to the contract.

[0033] The control center can refer to the department or system responsible for monitoring and managing contract risks.

[0034] When evaluating a contract, the model can predict the label of the contract and identify the risk type associated with the contract. The model classifies the contract based on the historical data learned during training. Based on the model's identification of the risk type, it generates corresponding modification suggestions. Specifically, this can be achieved through the design of the model's output layer, allowing the model to output modification suggestions. The risk type and modification suggestions are then sent to the control center via wireless communication technology.

[0035] S103: If the modified second decoration contract sent by the control center is received, the second decoration contract is transmitted to the blockchain platform.

[0036] The second renovation contract can refer to a revised version of the risk assessment results of the first renovation contract after review and modification by the control center. It usually includes changes, additions or deletions to the original contract content to reduce the risk of the contract or improve the enforceability of the contract. The second renovation contract should reflect the specific adjustments made by the control center based on the risk type and modification suggestions.

[0037] The blockchain platform can be a decentralized, distributed database system for securely storing and managing contract data. Through the blockchain, contract information can be maintained by multiple participants to ensure data transparency, immutability and traceability. Blockchain technology can be used to record the creation, modification and execution of contracts, providing a highly secure contract management method.

[0038] The system receives the modified second renovation contract sent by the control center. The contract content has been reviewed and modified to address the risks previously identified. The data of the second renovation contract is then sent to the blockchain using the API or smart contract interface provided by the blockchain platform. When sending the request, relevant metadata (such as timestamp, contract version, creator information, etc.) can be included for subsequent search and audit. The blockchain platform processes the request and stores the second renovation contract as a transaction record in the blockchain. The system can receive confirmation information to verify that the contract has been successfully uploaded to the blockchain.

[0039] On the basis of the above technical solution, optionally, after transmitting the second decoration contract to the blockchain platform, the method further includes: Continuously monitor the contract execution data of the second renovation contract through the preset smart contract; If a key node is read, the node type of the key node is obtained, a target operation is determined according to the node type and a preset operation rule, and the target operation is executed.

[0040] In this solution, the preset smart contract can refer to the contract program that is pre-written and deployed on the blockchain platform, which contains the code about the contract terms, conditions and execution logic. These smart contracts run automatically during the contract execution process to ensure that the contract terms are followed and reduce manual intervention.

[0041] Contract execution data may refer to all information related to the execution of the second renovation contract, including but not limited to project progress, payment records, quality inspection results, etc. Such data can be used to monitor the execution and status of the contract.

[0042] Key nodes can refer to time points or events that require special attention during the execution of the contract. For example, the project start date, payment node, and project completion date. These nodes are crucial to the smooth execution of the contract, and the system needs to continuously monitor the status of these nodes.

[0043] Node types can be specific tasks or operations that need to be completed at each node during the contract execution process. Specifically, they can include the start node: Task: Confirm the project start and sign the start-up document. It marks the official start of the project and ensures that all parties understand and agree to the conditions for project start. Payment node: Task: Process and confirm payment. Ensure that payment is completed within the agreed time to promote project progress. Inspection node: Task: Conduct periodic quality inspections to ensure that the construction meets the specifications. Find problems in time and make rectifications to avoid greater losses in the later stage. Document review node: Task: Submit and review necessary documents (such as design plans, completion reports). Ensure the compliance and completeness of all relevant documents to avoid missing key documents. Change management node: Task: Submit, review and confirm contract change applications. Manage project scope changes and ensure that all parties agree on this. Acceptance node: Task: Conduct final acceptance to confirm that the project delivery meets the contract requirements. Ensure that the project is delivered according to quality standards and meets all acceptance conditions.

[0044] Preset operation rules can include node completion confirmation: ensuring that each node completes its tasks within the specified time, such as confirming project launch, processing payments, etc. Automatic trigger conditions: when a node is not completed on time, the smart contract automatically triggers the corresponding action, such as sending a notification or warning. Compliance check: the operation of each key node must meet the requirements of the contract terms and laws and regulations to ensure compliance. Information update: once the node task is completed, the smart contract will update the status to reflect the progress of the project.

[0045] Target actions can include sending notifications: when the start node is not completed, sending reminders to relevant parties to urge them to confirm the project start. Recording payments: at the payment node, confirming the receipt of payments and updating the contract status to ensure that the conditions for subsequent nodes are met. Generating quality inspection reports: at the inspection node, generating quality inspection reports and recording the results for subsequent review. Document submission: at the document review node, requiring relevant parties to submit necessary documents and review them. Processing change requests: at the change management node, processing contract change requests and confirming them. Final acceptance: at the acceptance node, performing final project inspections and confirming delivery.

[0046] Smart contracts can continuously collect contract execution data and monitor the status of key nodes in real time. Once a key node is reached, the system automatically reads the node type. Based on the node type read, the system queries the preset operation rules to determine whether the target operation needs to be performed. If the operation conditions are met, the system performs the corresponding target operation (such as sending notifications, recording payments, etc.) and updates the contract execution status. The operation results are then recorded on the blockchain platform to ensure transparency and immutability, and the status is fed back to all relevant parties.

[0047] In this solution, by continuously monitoring the contract execution data, problems can be discovered in a timely manner to ensure that the project proceeds as planned. It reduces manual intervention, automatically executes contract terms, improves efficiency, and reduces error rates.

[0048] Based on the above technical solution, optionally, after determining the target operation according to the node type and the preset operation rules and executing the target operation, the method further includes: Continuously monitor the transaction status corresponding to each key node through a preset smart contract. If the transaction status is monitored to be in a transaction completion state, obtain transaction identification information, status update information and attribute information; A second zero-knowledge proof corresponding to each key node is generated according to the transaction identification information, status update information and attribute information through a preset smart contract, and the second zero-knowledge proof is transmitted to the blockchain platform.

[0049] In this solution, the transaction status may refer to the different stages of the current transaction during its execution, such as "pending", "processing", "transaction completed", etc.

[0050] The transaction completion state may be when all conditions of the transaction are met and all necessary operations are completed, the transaction enters the "transaction completion state".

[0051] The transaction identification information may be an identifier that uniquely identifies a transaction, and is usually a string or a number, used to distinguish different transactions.

[0052] The status update information may be specific information describing the change in transaction status, such as "changed from pending to transaction completed".

[0053] Attribute information can be additional information related to the transaction, such as transaction amount, parties involved, timestamp, etc.

[0054] The second zero-knowledge proof may be a zero-knowledge proof generated based on transaction identification information, state update information, and attribute information, and is intended to verify certain information without revealing specific content.

[0055] A smart contract can be deployed on the blockchain to manage and monitor the transaction status. Set triggers or events in the contract to monitor changes in the transaction status. For example, set events for key node status changes. The smart contract continuously monitors events related to each key node. Once the transaction status is updated, such as entering the "transaction completed state", the contract will be triggered to execute the corresponding logic. Specifically, the unique identifier of the current transaction can be obtained, and the information of the state change, such as "from pending to completed transaction", can be recorded, and other information related to the transaction, such as the parties involved, the transaction amount, etc., can be collected. The algorithm for generating the second zero-knowledge proof is preset in the smart contract. This proof should be based on the acquired transaction identification information, status update information, and attribute information. Call the function for generating the zero-knowledge proof in the contract, input the collected information, and generate a valid proof. The generated second zero-knowledge proof is then recorded on the blockchain to ensure that it cannot be tampered with and is traceable.

[0056] In this scheme, zero-knowledge proof allows the validity of transactions to be verified without revealing specific information, thereby protecting the privacy of users.

[0057] Based on the above technical solution, optionally, after determining the target operation according to the node type and the preset operation rules and executing the target operation, the method further includes: The execution status information of each key node is monitored through a preset smart contract, and the target access strategy and policy version information of each key node are determined based on the execution status information and the preset access strategy.

[0058] In this solution, execution status information may refer to the current status and progress of each key node during the execution of the smart contract. Specifically, it may include task completion status: indicating whether a key node (such as a payment node, acceptance node) has been completed. Timestamp: Records the start and end time of each key node to help monitor progress. Responses of participants: Decisions or actions taken by the parties involved at key nodes, such as whether payment has been confirmed. Compliance check results: Confirm whether a node meets preset standards or requirements, such as the results of a quality check. Exception report: Records any problems or delays that occur during execution.

[0059] Key nodes and their corresponding execution status information, such as payment nodes, acceptance nodes, etc., can be defined in smart contracts. Using blockchain technology, the execution status of each key node is recorded in real time, including task completion, timestamps, responses of participating parties, etc. When the status of a key node changes (such as task completion or delay), the smart contract automatically captures and updates the execution status information of the node. According to the preset access policy, the smart contract analyzes the current execution status information. This may include deciding whether to allow access to relevant information or perform subsequent operations based on the node type and completion status. In the smart contract, the target access policy for each key node is dynamically generated or adjusted based on the execution status and preset access policy, including the necessary policy version information. If the access policy or execution status changes, the smart contract updates the policy version information to ensure that all participants follow the latest access rights and rules.

[0060] In this solution, smart contracts can automatically update and execute access policies, reduce manual intervention, and lower management costs.

[0061] Based on the above technical solution, optionally, after determining the target access strategy and strategy version information of each key node, the method further includes: Regenerate the first public parameter, and regenerate the encryption key of each key node according to the first public parameter, the target access policy of each key node, and the execution status information; The contract information of each key node is encrypted according to the encryption key to obtain the ciphertext information of the contract information of each key node, and the policy version information of each key node is embedded in the ciphertext information.

[0062] In this solution, new first public parameters can be generated through the Trusted Setup phase based on the current environment and requirements, which can include selecting new random group elements, updating hash functions, etc. According to the current execution status information and the preset access policy, the target access policy of each key node is identified. Using the new first public parameters, the target access policy of each key node and the execution status information, a new encryption key is generated through an encryption algorithm (such as a symmetric or asymmetric encryption algorithm). This process should ensure that the encryption key is combined with these input parameters to make it targeted. Using the generated encryption key, the contract information of each key node is encrypted. This process will generate ciphertext information. In the generated ciphertext information, the policy version information of each key node is embedded. This can be achieved by embedding the policy version information as additional data in the ciphertext to ensure that the access policy used can be identified and verified during decryption.

[0063] In this solution, by combining with the access policy of a specific node, it is possible to flexibly control who can access which data. Only qualified users can decrypt the corresponding ciphertext, ensuring that the data is only accessed by authorized personnel. When the execution status or requirements change, regenerating encryption keys and access policies can quickly adapt to new situations, improving the flexibility and responsiveness of the system.

[0064] S104, input the second decoration contract into the preset contract information extraction model to obtain the contract information, and encrypt the contract information through the preset attribute encryption algorithm to obtain the ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform.

[0065] The preset contract information extraction model can be an automated model for extracting key information from the contract text. The model can be based on natural language processing technology to analyze the structure and content of the contract and extract important information such as contract terms, amount, date, and information signed by both parties. This information will be used for subsequent processing and analysis.

[0066] The contract information may refer to a collection of all key information extracted from the second renovation contract, specifically, it may include the contract number, the two parties to the contract, the contract amount, the start and end dates of the contract, the main terms, and the breach of contract terms.

[0067] The preset attribute encryption algorithm can be an encryption method that allows the contract information to be encrypted while defining who can decrypt and access the information according to a specific access control policy. Attribute encryption makes it impossible for unauthorized users to obtain plaintext information even if the ciphertext is leaked.

[0068] Ciphertext information may refer to encrypted contract information, the content of which is unreadable to unauthorized users. Ciphertext is the result of contract information being encrypted using a preset attribute encryption algorithm for secure storage and transmission.

[0069] The modified second decoration contract can be input into the preset contract information extraction model. The contract can be a text file or other formats. The contract information extraction model analyzes the contract text, extracts the key information in the contract, and generates structured contract information data. The contract information is then encrypted by a preset attribute encryption algorithm to obtain the ciphertext information of the contract information, and the ciphertext information is sent to the blockchain platform through a system call or API interface. A secure transmission protocol (such as HTTPS) can be used to ensure the security of data during transmission. Verify whether the ciphertext information is successfully stored on the blockchain platform, and record the relevant transaction information to ensure the immutability and traceability of the data.

[0070] S105, generating a first zero-knowledge proof of the contract information and the ciphertext information, and transmitting the first zero-knowledge proof to the blockchain platform.

[0071] First, zero-knowledge proof can be used to prove the authenticity of a statement without revealing specific information. It allows one party (the prover) to prove to another party (the verifier) ​​that they know a secret (such as contract information or ciphertext information) without revealing the content of the secret. First, zero-knowledge proof is often used to enhance the privacy protection of data, ensuring that sensitive information is not directly exposed during data sharing or storage.

[0072] You can choose a suitable zero-knowledge proof protocol (such as zk-SNARKs or zk-STARKs) based on your specific needs. These protocols provide different performance and privacy protection characteristics. Use the contract information and ciphertext information to build an instance of zero-knowledge proof. This usually includes taking the key attributes of the contract and the ciphertext information as input and preparing the relevant proof calculations. Run the zero-knowledge proof generation algorithm to generate the first zero-knowledge proof. The proof will contain the prover's knowledge of the contract information and ciphertext information, but not its specific content. Send the first zero-knowledge proof to the blockchain platform using a secure transmission protocol (such as HTTPS). Data can be uploaded to the chain through smart contracts or API interfaces. Verify whether the zero-knowledge proof is successfully stored on the blockchain platform, and record the relevant transaction information to ensure its immutability and traceability.

[0073] In an embodiment of the present application, a first decoration contract sent by a user is received, the first decoration contract is input into a preset risk assessment model to obtain a risk score, and whether there is a contract risk is determined according to the risk score and the preset risk score threshold; if there is a contract risk, the risk type and modification suggestions are determined by the preset risk assessment model, and the risk type and modification suggestions are sent to the control center; if the modified second decoration contract sent by the control center is received, the second decoration contract is transmitted to the blockchain platform; the second decoration contract is input into a preset contract information extraction model to obtain contract information, and the contract information is encrypted by a preset attribute encryption algorithm to obtain ciphertext information of the contract information, and the ciphertext information is transmitted to the blockchain platform; the first zero-knowledge proof of the contract information and the ciphertext information is generated, and the first zero-knowledge proof is transmitted to the blockchain platform. Through the above-mentioned blockchain-based decoration contract risk assessment and encryption management method, the automated process can reduce manual intervention and improve the speed and efficiency of contract processing. The contract and related information are stored on the blockchain to ensure the immutability of the data and enhance trust. Encrypting the contract information and protecting sensitive information can ensure that only authorized parties can access it. Generating zero-knowledge proofs allows the validity of a contract to be proven without revealing the specific contract content, which can improve the privacy of data sharing.

[0074] Based on the above technical solution, optional, preset risk assessment model training steps include: Acquire historical renovation contracts, annotate risk score labels on the historical renovation contracts, and create a first data set based on the historical renovation contracts and the risk score labels; Acquire historical risky renovation contracts, mark the risk type labels and modification suggestion labels of the historical risky renovation contracts, and create a second data set according to the historical risky renovation contracts, the risk type labels, and the modification suggestion labels; Constructing a risk assessment model, and training the risk assessment model according to the first data set and the second data set until the risk assessment model reaches a preset risk assessment model standard.

[0075] In this scenario, historical renovation contracts can be renovation contracts that have been completed or carried out in the past, which are usually used to analyze and assess risks. They contain detailed information about the project, such as the contract amount, construction party, time schedule, etc.

[0076] The risk score label can be a quantitative indicator given after evaluating the historical renovation contract, indicating the size of the potential risk of the contract. The score is usually based on multiple factors, such as the complexity of the contract terms, historical issues of the project, construction quality, etc.

[0077] The first data set may be a data set consisting of all historical renovation contracts and their corresponding risk score labels. This data set is used to train the risk assessment model so that the model can learn the relationship between the contract and the risk score.

[0078] Historical risk renovation contracts may refer to contracts that have been identified as having risks in historical contracts. These contracts are usually accompanied by problems or disputes and require special attention.

[0079] The risk type label can be used to identify specific risk types in historical risk renovation contracts, such as quality risk, time delay risk, cost overrun risk, etc. This helps the model identify and classify different risks.

[0080] The modification suggestion label can be a specific modification suggestion provided for the risk types identified in the historical risk renovation contracts, such as modifying the contract terms, adjusting the payment arrangements, etc., to reduce potential risks.

[0081] The second data set may be a data set consisting of historical risky renovation contracts and their corresponding risk type labels and modification suggestion labels. This data set is used to help the model understand the relationship between risk types and response strategies.

[0082] The preset risk assessment model standards may refer to a series of indicators or thresholds used to evaluate model performance, such as accuracy, recall, F1 score, etc. The model must meet these standards to be considered effective.

[0083] Historical renovation contracts can be extracted from company archives, databases, or other storage systems. Experts or teams evaluate the potential risks of each contract based on the contract content and give a score (e.g., a scale of 1 to 5). The score is recorded in the dataset and associated with the corresponding contract information. All historical renovation contracts are combined with their risk score labels to form a structured dataset (the first dataset). Contracts with risk scores above a certain threshold are screened out from the first dataset to form a set of historical risk renovation contracts. Each historical risk renovation contract is analyzed and labeled with specific risk types (e.g., delay, quality, etc.). Based on the risk type, possible modification suggestions are provided for each contract to reduce the risk. The historical risk renovation contracts are combined with their risk type labels and modification suggestion labels to form the second dataset. Then, a suitable machine learning model (e.g., decision tree, random forest, or neural network) is selected for risk assessment. The first dataset and the second dataset are divided into a training set and a test set. The model is trained using the training set data, and the model parameters are adjusted and cross-validated at the same time. The model performance is evaluated using the test set, and indicators such as accuracy and recall are calculated. Specific evaluation indicators, such as accuracy and F1 score, are set as the criteria for model qualification. Optimize the model based on the evaluation results, adjust parameters, and retrain until the model reaches the preset standards.

[0084] In this solution, historical data is used for modeling, making risk assessment more objective and reliable, and avoiding the bias of human subjective judgment. The systematic approach helps identify potential risks, improves the foresight of problems in renovation contracts, and reduces uncertainty in projects.

[0085] Based on the above technical solution, the optional training steps of the preset contract information extraction model include: Acquire historical renovation contracts, mark contract information tags of the historical renovation contracts, and construct a third data set based on the historical renovation contracts and the contract information tags; A contract information extraction model is constructed, and the contract information extraction model is trained according to the third data set until the contract information extraction model reaches a preset contract information extraction model training standard.

[0086] In this solution, the contract information label can be a mark of key information in the historical renovation contract, such as project name, contract amount, start date, end date, basic information of Party A and Party B, payment terms, liability for breach of contract, etc. These labels help the model understand and extract relevant information.

[0087] The third data set can be a set of historical renovation contracts and their corresponding contract information labels. Each piece of data contains a historical contract text and its annotated contract information, which is usually stored in a structured form, such as CSV, JSON, etc., to facilitate model training.

[0088] The preset contract information extraction model training standards may include evaluation indicators such as model accuracy, recall, F1 score, etc. These standards set the performance level that the model needs to achieve during the training and validation phases to ensure that the model can effectively extract contract information.

[0089] You can collect the company's past decoration contracts to ensure the diversity and representativeness of the contracts to cover different contract types and contents. Organize an expert team to review and annotate the collected contracts one by one to ensure that the key information in the contracts is accurately identified. You can use annotation tools to improve efficiency. Organize the annotated contracts and their corresponding labels into a third data set to ensure data cleaning and formatting for subsequent model training. Select a suitable machine learning or deep learning algorithm (such as conditional random fields, LSTM, BERT, etc.) to build a contract information extraction model. Use the third data set to train the contract information extraction model, continuously adjust the hyperparameters, and optimize the model performance. Test the performance of the model on the validation set, calculate indicators such as accuracy, recall, and F1 score, and ensure that the model meets the preset training standards. Based on the evaluation results, optimize the model architecture or training process, and add training data as needed for retraining until the preset standards are met.

[0090] In this solution, model training can reduce human errors and ensure the accuracy and consistency of information extraction. It can also reduce the time for manual review and extraction of contract information and improve work efficiency.

[0091] Embodiment 2 Figure 2 This is a flow chart of the blockchain-based renovation contract risk assessment and encryption management method provided in Example 2 of this application, such as Figure 2 As shown, the specific method includes the following steps: S201, obtaining a preset access strategy and initial status information of a second renovation contract, and determining a target access strategy according to the initial status information and the preset access strategy; wherein the preset access strategy includes strategy version information.

[0092] A preset access policy can be a predefined set of rules that specifies which users or systems can access specific data or resources, usually including user roles, permissions, and conditions.

[0093] The initial status information may refer to initial data related to the second renovation contract, such as the creation time of the contract, the identities of the parties involved, the contract status, etc. This information provides context for subsequent processing and decision-making.

[0094] The target access policy may be a policy dynamically generated based on the initial state information and the preset access policy, specifically describing which users or systems may access the encrypted contract information in the current context, possibly taking into account the current contract state and the roles of the parties involved.

[0095] The policy version information may refer to a version number or identifier of an access policy, which is used to track and manage different versions of access policies to ensure that correct rules are used during encryption and decryption.

[0096] Can be obtained through system configuration or database call, usually defined at system initialization, including roles, permissions, and access conditions. Extract initial status information from the contract management system, which can include contract creation date, party information, current status, etc. Evaluate the status of the current contract and the identity of the parties involved to determine who should have access to the contract information. Combine the preset access policy with the initial status information to generate a specific target access policy, which may contain specific conditions and restrictions.

[0097] S202: Generate a first public parameter, and generate an encryption key according to the first public parameter, a target access policy, and initial state information.

[0098] The first public parameter may refer to a set of public parameters generated during the encryption process, which usually include random numbers and group elements related to the encryption algorithm. These parameters are the basis for ensuring the security and effectiveness of the encryption process.

[0099] The encryption key may be a key generated according to the first public parameter, the target access policy and the initial state information, and used to encrypt the contract information, ensuring that only users who meet specific conditions can decrypt and access the contract content.

[0100] A secure random number generation algorithm can be used to generate the first public parameter based on preset security parameters. These parameters usually include group elements and random numbers required by the encryption algorithm. The first public parameter, the target access policy, and the initial state information are used as input to generate the encryption key using a predetermined algorithm. This step ensures that the generated key is associated with the specific access requirements and contract status.

[0101] S203, encrypt the contract information according to the encryption key to obtain ciphertext information, and embed the policy version information in the ciphertext information.

[0102] The generated encryption key can be used to encrypt the information of the second decoration contract to obtain ciphertext information. Finally, the policy version information is added to the ciphertext information to ensure that the correct access policy is used during decryption.

[0103] In this embodiment, the encrypted contract information ensures that only authorized users can access it, preventing unauthorized access and data leakage. The encryption key is dynamically generated according to the target access policy and initial state information, so that the system can adapt to different access requirements and environmental changes.

[0104] Embodiment 3 Figure 3 This is a flowchart of the blockchain-based renovation contract risk assessment and encryption management method provided in Example 3 of the present application, such as Figure 3 As shown, the specific method includes the following steps: S301, receiving a data acquisition request from a client, determining user attribute information according to the data acquisition request, generating zero-knowledge proof challenge information, and sending the zero-knowledge proof challenge information to the client.

[0105] A data acquisition request may be a request initiated by a client to a server, which usually includes an identifier of the specific data that needs to be accessed and access permission requirements. Specifically, it may include the identity information of the requester, the type of data required, the reason for access, etc.

[0106] User attribute information can be a set of data that describes user characteristics and is used to determine the user's access rights. Specifically, it can include user roles (such as administrator, ordinary user), permission levels (such as the ability to view, edit or delete data), access history (such as files or contracts accessed in the past), etc.

[0107] The zero-knowledge proof challenge information may be a request information for requiring a client to prove that it possesses certain knowledge (such as a key) without directly revealing the knowledge.

[0108] A request from a client may be received, which usually includes the type of data to be accessed and the required node information. The request may include the user's identity so that the user's attribute information can be subsequently confirmed. Based on the user's identity in the client request, the system queries the user's attribute information, such as role, permission level, etc. This attribute information is used to determine whether the user has access to the requested data. The system generates zero-knowledge proof challenge information based on the user's attribute information and the access request. This information is used to verify whether the user has access rights without revealing specific attribute information. The generated zero-knowledge proof challenge information is then sent to the client, which needs to use this information to generate the corresponding third zero-knowledge proof.

[0109] S302, receiving a third zero-knowledge proof generated by the client according to the zero-knowledge proof challenge information, determining a target key node and a target access policy according to the data acquisition request, and acquiring a second zero-knowledge proof corresponding to the target key node.

[0110] The third zero-knowledge proof can be a proof generated by the client based on the received challenge information, indicating that it meets certain conditions (such as having the authority to access specific data).

[0111] Target key nodes can be specific nodes that users want to access or operate during contract execution or data flow. These nodes usually correspond to key steps or events in the contract. They can include specific contract terms, payment nodes, quality checks, document reviews, change management, etc. These are key points that users need to pay attention to or obtain information.

[0112] The client generates a third zero-knowledge proof based on the challenge information received and sends it back to the system. This proof indicates that the user meets the conditions of the access request based on his attribute information. The system parses the data acquisition request and determines the target key node that the user wants to access and the related target access policy. Based on the determined target key node, the system retrieves the second zero-knowledge proof of the node. This proof indicates that the node meets the preset access policy.

[0113] S303: Verify, based on the first zero-knowledge proof and the second zero-knowledge proof, whether the third zero-knowledge proof meets a preset challenge condition.

[0114] The third zero-knowledge proof can be verified using the first zero-knowledge proof (generated previously) and the second zero-knowledge proof. The verification process ensures that the user's third zero-knowledge proof meets the preset challenge conditions, for example, whether a valid proof is provided to confirm their access rights.

[0115] The preset challenge conditions may refer to specific conditions that the system requires to be met during the zero-knowledge proof process. These conditions may include: the third zero-knowledge proof must be able to pass the verification of the first and second zero-knowledge proofs. Prove that the user has the authority to access the target key node. Ensure that the user attribute information is consistent with the target access policy.

[0116] S304: If the preset challenge condition is met, a second public parameter is generated, a decryption key is generated according to the user attribute information, the target access policy, the execution status information and the second public parameter, and the decryption key is sent to the client.

[0117] The second public parameter may refer to a set of public parameters used in the decryption process. These parameters are usually generated based on the security settings of the system and may include randomly generated group elements and hash values ​​related to specific access policies.

[0118] The decryption key is a key used to convert ciphertext information back to plaintext information. The process of generating the decryption key is based on the user's attribute information, the target access policy, the execution state information, and the second public parameter.

[0119] A client can be a user or application that interacts with the system. It can be a mobile app, web app, or any program that supports communication with the server. The client is responsible for sending data retrieval requests, receiving decryption keys and other necessary information, and interacting with the backend smart contract or blockchain system to access protected contract information.

[0120] If the third zero-knowledge proof is verified, the system generates the second public parameters, which are required for further processing. Then using the user attribute information, the target access policy, the execution status information, and the second public parameters, the system generates a decryption key. This key is used to convert the encrypted data into readable plaintext information. Finally, the system sends the generated decryption key to the client, allowing it to access the requested data.

[0121] In this embodiment, through zero-knowledge proof, users can prove their access rights without exposing sensitive attributes, reducing the risk of data leakage. The system can dynamically determine access rights based on the user's specific attributes and requests, improving flexibility.

[0122] Embodiment 4 Figure 4 This is a schematic diagram of the structure of a blockchain-based renovation contract risk assessment and encryption management system provided in Example 4 of the present application. Figure 4 As shown, the system is used to implement a blockchain-based renovation contract risk assessment and encryption management system method provided in embodiments 1, 2, and 3. The system specifically includes the following: The risk determination module 401 is used to receive a first decoration contract sent by a user, input the first decoration contract into a preset risk assessment model to obtain a risk score, and determine whether there is a contract risk according to the risk score and a preset risk score threshold; An evaluation module 402 is used to determine the risk type and modification suggestions through a preset risk evaluation model if there is a contract risk, and send the risk type and modification suggestions to the control center; The transmission module 403 is used to transmit the second decoration contract to the blockchain platform if the modified second decoration contract sent by the control center is received; The encryption module 404 is used to input the second renovation contract into a preset contract information extraction model to obtain contract information, encrypt the contract information using a preset attribute encryption algorithm to obtain ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform; The zero-knowledge proof generation module 405 is used to generate a first zero-knowledge proof of the contract information and the ciphertext information, and transmit the first zero-knowledge proof to the blockchain platform.

[0123] In the embodiment of the present application, the risk determination module is used to receive the first decoration contract sent by the user, input the first decoration contract into the preset risk assessment model, obtain the risk score, and determine whether there is a contract risk according to the risk score and the preset risk score threshold; the assessment module is used to determine the risk type and modification suggestions through the preset risk assessment model if there is a contract risk, and send the risk type and modification suggestions to the control center; the transmission module is used to transmit the second decoration contract to the blockchain platform if the modified second decoration contract sent by the control center is received; the encryption module is used to input the second decoration contract into the preset contract information extraction model to obtain the contract information, and encrypt the contract information through the preset attribute encryption algorithm to obtain the ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform; the zero-knowledge proof generation module is used to generate the first zero-knowledge proof of the contract information and the ciphertext information, and transmit the first zero-knowledge proof to the blockchain platform. Through the above-mentioned blockchain-based decoration contract risk assessment and encryption management system, the automated process can reduce manual intervention and improve the speed and efficiency of contract processing. The contract and related information are stored on the blockchain to ensure the immutability of the data and enhance trust. Encrypting contract information and protecting sensitive information can ensure that only authorized parties can access it. Generating zero-knowledge proofs allows the validity of a contract to be proven without revealing the specific content of the contract, which can improve the privacy of data sharing.

[0124] The above are only preferred embodiments of the present application and the technical principles used. The present application is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions that can be made by those skilled in the art will not deviate from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the claims.

Claims

1. A blockchain-based renovation contract risk assessment and encryption management method, characterized in that: The method comprises: receiving a first decoration contract sent by a user, inputting the first decoration contract into a preset risk assessment model to obtain a risk score, and determining whether there is a contract risk according to the risk score and a preset risk score threshold; If there is a contract risk, the risk type and modification suggestions are determined through a preset risk assessment model, and the risk type and modification suggestions are sent to the control center; If the modified second decoration contract sent by the control center is received, the second decoration contract is transmitted to the blockchain platform; Input the second renovation contract into a preset contract information extraction model to obtain contract information, encrypt the contract information using a preset attribute encryption algorithm to obtain ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform; Generate a first zero-knowledge proof of the contract information and the ciphertext information, and transmit the first zero-knowledge proof to the blockchain platform.

2. According to the blockchain-based renovation contract risk assessment and encryption management method of claim 1, it is characterized in that: After transmitting the second renovation contract to the blockchain platform, the method further includes: Continuously monitor the contract execution data of the second renovation contract through the preset smart contract; If a key node is read, the node type of the key node is obtained, a target operation is determined according to the node type and a preset operation rule, and the target operation is executed.

3. The blockchain-based renovation contract risk assessment and encryption management method according to claim 2 is characterized in that: After determining the target operation according to the node type and the preset operation rules and executing the target operation, the method further includes: Continuously monitor the transaction status corresponding to each key node through a preset smart contract. If the transaction status is monitored to be in a transaction completion state, obtain transaction identification information, status update information and attribute information; A second zero-knowledge proof corresponding to each key node is generated according to the transaction identification information, status update information and attribute information through a preset smart contract, and the second zero-knowledge proof is transmitted to the blockchain platform.

4. The blockchain-based renovation contract risk assessment and encryption management method according to claim 1 is characterized in that: The contract information is encrypted using a preset attribute encryption algorithm to obtain the ciphertext information of the contract information, including: Obtaining a preset access strategy and initial state information of the second renovation contract, and determining a target access strategy according to the initial state information and the preset access strategy; wherein the preset access strategy includes strategy version information; Generate a first public parameter, and generate an encryption key according to the first public parameter, the target access policy, and the initial state information; The contract information is encrypted according to the encryption key to obtain ciphertext information, and the policy version information is embedded in the ciphertext information.

5. The blockchain-based renovation contract risk assessment and encryption management method according to claim 2 is characterized in that: After determining the target operation according to the node type and the preset operation rules and executing the target operation, the method further includes: The execution status information of each key node is monitored through a preset smart contract, and the target access strategy and policy version information of each key node are determined based on the execution status information and the preset access strategy.

6. The blockchain-based renovation contract risk assessment and encryption management method according to claim 5 is characterized in that: After determining the target access strategy and strategy version information of each key node, the method further includes: Regenerate the first public parameter, and regenerate the encryption key of each key node according to the first public parameter, the target access policy of each key node, and the execution status information; The contract information of each key node is encrypted according to the encryption key to obtain the ciphertext information of the contract information of each key node, and the policy version information of each key node is embedded in the ciphertext information.

7. The blockchain-based renovation contract risk assessment and encryption management method according to claim 6 is characterized in that: After generating the first zero-knowledge proof of the contract information and the ciphertext information, and transmitting the first zero-knowledge proof to the blockchain platform, the method further includes: Receive a data acquisition request from a client, determine user attribute information according to the data acquisition request, generate zero-knowledge proof challenge information, and send the zero-knowledge proof challenge information to the client; Receiving a third zero-knowledge proof generated by the client according to the zero-knowledge proof challenge information, determining a target key node and a target access policy according to the data acquisition request, and acquiring a second zero-knowledge proof corresponding to the target key node; Verifying whether the third zero-knowledge proof meets a preset challenge condition according to the first zero-knowledge proof and the second zero-knowledge proof; If the preset challenge conditions are met, a second public parameter is generated, a decryption key is generated according to the user attribute information, the target access policy, the execution status information and the second public parameter, and the decryption key is sent to the client.

8. The blockchain-based renovation contract risk assessment and encryption management method according to claim 1 is characterized in that: The training steps of the preset risk assessment model include: Acquire historical renovation contracts, annotate risk score labels on the historical renovation contracts, and create a first data set based on the historical renovation contracts and the risk score labels; Acquire historical risky renovation contracts, mark the risk type labels and modification suggestion labels of the historical risky renovation contracts, and create a second data set according to the historical risky renovation contracts, the risk type labels, and the modification suggestion labels; Constructing a risk assessment model, and training the risk assessment model according to the first data set and the second data set until the risk assessment model reaches a preset risk assessment model standard.

9. The blockchain-based renovation contract risk assessment and encryption management method according to claim 1 is characterized in that: The training steps of the preset contract information extraction model include: Acquire historical renovation contracts, mark contract information tags of the historical renovation contracts, and construct a third data set according to the historical renovation contracts and the contract information tags; A contract information extraction model is constructed, and the contract information extraction model is trained according to the third data set until the contract information extraction model reaches a preset contract information extraction model training standard.

10. A blockchain-based renovation contract risk assessment and encryption management system, characterized in that: The system comprises: A risk determination module, configured to receive a first decoration contract sent by a user, input the first decoration contract into a preset risk assessment model to obtain a risk score, and determine whether there is a contract risk according to the risk score and a preset risk score threshold; An assessment module is used to determine the risk type and modification suggestions through a preset risk assessment model if there is a contract risk, and send the risk type and modification suggestions to the control center; A transmission module, for transmitting the second decoration contract to the blockchain platform upon receiving the modified second decoration contract sent by the control center; An encryption module, used to input the second decoration contract into a preset contract information extraction model to obtain contract information, encrypt the contract information through a preset attribute encryption algorithm to obtain ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform; The zero-knowledge proof generation module is used to generate a first zero-knowledge proof of the contract information and the ciphertext information, and transmit the first zero-knowledge proof to the blockchain platform.

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