Blockchain-based Renovation Contract Risk Assessment and Encryption Management Method and System

Abstract

The present application discloses a method and system for risk assessment and encryption management of decoration contracts based on blockchain. The present application belongs to the field of data management. The method includes: receiving a first decoration contract sent by a user, and determining whether there is a contract risk in the first decoration contract; if there is, determining the risk type and modification suggestions; if the modified second decoration contract is received, transmitting the second decoration contract to the blockchain platform; determining the contract information of the second decoration contract, encrypting it to obtain ciphertext information, and transmitting it to the blockchain platform; generating a first zero-knowledge proof and transmitting it to the blockchain platform. The automated process of this solution can reduce manual intervention, improve the speed and efficiency of contract processing. Storing contracts and related information on the blockchain ensures the immutability of data and enhances trust. Encrypting contract information to protect sensitive information can ensure that only authorized parties can access it. Generating zero-knowledge proofs can improve the privacy of data sharing.

Description

Technical Field

[0001] This application relates to the technical field of data management, and particularly to a method and system for risk assessment and encryption management of decoration contracts based on blockchain. Background Art

[0002] With the continuous expansion of the decoration market, the contract content is complex and diverse, and potential legal and economic risks also increase accordingly. 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, the use of encryption management technology to encrypt contract information ensures the security and integrity of information during transmission and storage, prevents the leakage of sensitive information, and provides a solid guarantee for the smooth progress of decoration projects.

[0003] Nowadays, the risk assessment of decoration contracts is usually carried out manually. Through the item-by-item review of contract terms by a professional team, potential legal and economic risks are identified and evaluation opinions are given. Then, traditional encryption algorithms (such as AES, RSA) are used to encrypt the contract files to ensure that the files are not accessed without authorization during transmission and storage. This encryption method requires both parties to share the key in order to decrypt and view the contract content.

[0004] However, manual assessment of contract risks requires a large amount of human resources and time, especially when facing a large number of contracts, the efficiency is low. Although traditional encryption algorithms can protect contract files from unauthorized access, the management and distribution of keys are potential security risks. If the key is leaked or lost, the encrypted file will face the risk of being decrypted. Summary of the Invention

[0005] The embodiments of this application provide a method and system for risk assessment and encryption management of decoration contracts based on blockchain, which solve the problems in the prior art that manual assessment of contract risks requires a large amount of human resources and time, especially when facing a large number of contracts, the efficiency is low. Although traditional encryption algorithms can protect contract files from unauthorized access, the management and distribution of keys are potential security risks. If the key is leaked or lost, the encrypted file will face the risk of being decrypted.

[0006] In a first aspect, the embodiments of this application provide a method for risk assessment and encryption management of decoration contracts based on blockchain, and the method includes:

[0007] 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;

[0008] If there is a contract risk, determine the risk type and modification suggestions through a preset risk assessment model, and send the risk type and modification suggestions to the control center;

[0009] If the modified second decoration contract sent by the control center is received, transmit the second decoration contract to the blockchain platform;

[0010] Input the second decoration contract into a preset contract information extraction model to obtain contract information, and encrypt the contract information through a preset attribute encryption algorithm to obtain the ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform;

[0011] 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.

[0012] Further, after transmitting the second decoration contract to the blockchain platform, the method further includes:

[0013] Continuously monitor the contract execution data of the second decoration contract through a preset smart contract;

[0014] If a key node is read, obtain the node type of the key node, determine the target operation according to the node type and preset operation rules, and execute the target operation.

[0015] Further, after determining the target operation according to the node type and preset operation rules and executing the target operation, the method further includes:

[0016] Continuously monitor the transaction status corresponding to each key node through a preset smart contract. If it is monitored that the transaction status is in the transaction completion state, obtain the transaction identification information, status update information, and attribute information;

[0017] Generate the second zero-knowledge proof corresponding to each key node through a preset smart contract according to the transaction identification information, status update information, and attribute information, and transmit the second zero-knowledge proof to the blockchain platform.

[0018] Further, encrypting the contract information through a preset attribute encryption algorithm to obtain the ciphertext information of the contract information includes:

[0019] Obtain the preset access policy and the initial state information of the second decoration contract, and determine the target access policy according to the initial state information and the preset access policy; wherein, the preset access policy includes policy version information;

[0020] Generate the first public parameter, and generate the encryption key according to the first public parameter, the target access policy, and the initial state information;

[0021] Encrypt the contract information according to the encryption key to obtain ciphertext information, and embed the policy version information in the ciphertext information.

[0022] Further, after determining the target operation according to the node type and the preset operation rules and executing the target operation, the method further includes:

[0023] Monitor the execution status information of each key node through a preset smart contract, and determine the target access policy and policy version information of each key node according to the execution status information and the preset access policy.

[0024] Further, after determining the target access policy and policy version information of each key node, the method further includes:

[0025] 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;

[0026] Encrypt the contract information of each key node according to the encryption key to obtain the ciphertext information of the contract information of each key node, and embed the policy version information of each key node in the ciphertext information.

[0027] Further, 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:

[0028] Receive the data acquisition request of the client, determine the user attribute information according to the data acquisition request, and generate zero-knowledge proof challenge information, and send the zero-knowledge proof challenge information to the client;

[0029] Receive the third zero-knowledge proof generated by the client according to the zero-knowledge proof challenge information, determine the target key node and the target access policy according to the data acquisition request, and obtain the second zero-knowledge proof corresponding to the target key node;

[0030] Verify whether the third zero-knowledge proof meets the preset challenge conditions according to the first zero-knowledge proof and the second zero-knowledge proof;

[0031] If it meets the preset challenge conditions, generate the second public parameter, generate a decryption key according to the user attribute information, the target access policy, the execution status information, and the second public parameter, and send the decryption key to the client.

[0032] Further, the training steps of the preset risk assessment model include:

[0033] Obtain historical renovation contracts, label the risk score tags of the historical renovation contracts, and create a first data set based on the historical renovation contracts and the risk score tags;

[0034] Obtain historical risky renovation contracts, label the risk type tags and modification suggestion tags of the historical risky renovation contracts, and create a second data set based on the historical risky renovation contracts, the risk type tags and the modification suggestion tags;

[0035] Construct a risk assessment model, and train the risk assessment model according to the first data set and the second data set until the risk assessment model meets the preset risk assessment model standard.

[0036] Further, the training steps of the preset contract information extraction model include:

[0037] Obtain historical renovation contracts, label the 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;

[0038] Construct a contract information extraction model, and train the contract information extraction model according to the third data set until the contract information extraction model meets the preset contract information extraction model training standard.

[0039] According to the second aspect of the present application, a blockchain-based renovation contract risk assessment and encryption management system is provided, and the system includes:

[0040] A risk determination module, configured to receive a first renovation contract sent by a user, input the first renovation 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;

[0041] An evaluation module, configured to, if there is a contract risk, determine the risk type and modification suggestions through a preset risk assessment model, and send the risk type and modification suggestions to the control center;

[0042] A transmission module, configured to, if receiving a modified second renovation contract sent by the control center, transmit the second renovation contract to the blockchain platform;

[0043] An encryption module, configured to input the second renovation 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;

[0044] A zero-knowledge proof generation module, configured 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.

[0045] In an embodiment of the present application, a first decoration contract sent by a user is received, and the first decoration contract is input into a preset risk assessment model to obtain a risk score. Whether there is a contract risk is determined 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 the preset risk assessment model, and the risk type and modification suggestions are sent to the control center; if a 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 through a preset attribute encryption algorithm to obtain ciphertext information of the contract information, and the ciphertext information is transmitted to the blockchain platform; a 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 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. Storing the contract and related information on the blockchain ensures the immutability of the data and enhances trust. Encrypting the contract information to protect sensitive information can ensure that only authorized parties can access it. Generating a zero-knowledge proof allows proving the validity of the contract without disclosing the specific contract content, which can improve the privacy of data sharing. Description of the Drawings

[0046] Figure 1 is a flowchart of the blockchain-based decoration contract risk assessment and encryption management method provided in the first embodiment of the present application;

[0047] Figure 2 is a flowchart of the blockchain-based decoration contract risk assessment and encryption management method provided in the second embodiment of the present application;

[0048] Figure 3 is a flowchart of the blockchain-based decoration contract risk assessment and encryption management method provided in the third embodiment of the present application;

[0049] Figure 4 is a structural diagram of the blockchain-based decoration contract risk assessment and encryption management system provided in the fourth embodiment of the present application. Detailed Embodiments

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following further describes the specific embodiments of this application in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described herein are only for explaining this application and not for limiting this application. Additionally, it should be noted that for ease of description, only the parts related to this application are shown in the drawings rather than all 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 flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of the operations 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 operations are completed, but it can also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0051] The following will clearly describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of this application.

[0052] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. generally belong to the same category, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally represents an "or" relationship between the associated objects before and after.

[0053] The following combines the accompanying drawings to detail the blockchain-based renovation contract risk assessment and encryption management method provided in the embodiments of this application through specific embodiments and their application scenarios.

[0054] Embodiment 1

[0055] Figure 1 is a schematic flowchart of the blockchain-based renovation contract risk assessment and encryption management method provided in Embodiment 1 of this application. As Figure 1 shown, it specifically includes the following steps:

[0056] S101. Receive the first decoration contract sent by the 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.

[0057] First, the usage scenario of this solution can be a scenario for risk assessment and encryption of decoration contracts.

[0058] Based on the above usage scenario, it can be understood that the execution subject of this application can be the decoration contract risk assessment and encryption management system, and no excessive limitation is made here.

[0059] The first decoration contract can be the contract text submitted by the user for the first time, and can include specific requirements, terms and conditions of the decoration project.

[0060] The preset risk assessment model can be an algorithm or a machine learning model, which is trained to identify potential risks in the contract.

[0061] The risk score can be a numerical value output by the risk assessment model, indicating the overall risk level of the contract.

[0062] The preset risk score threshold can be a benchmark numerical value set in advance, which is used to determine the high or low of the risk score.

[0063] The user can upload the first decoration contract through the system interface (such as a website or an 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. OCR (Optical Character Recognition) technology can be used (if it is in picture format) or text parsing technology (if it is in document format). Format the extracted contract text into the input format required by the risk assessment model to ensure that all key information (such as terms, amounts, time, etc.) is included. Then input the prepared contract information into the preset risk assessment model. The model can analyze the contract content and identify potential risk factors. Then output a risk score, which can be a numerical value indicating the overall risk level of the contract. Compare the generated risk score with the preset risk score threshold. The threshold can be set according to the company's policy or historical data. If the risk score is higher than the threshold, the system determines that there is a contract risk.

[0064] S102. If there is a contract risk, determine the risk type and modification suggestions through the preset risk assessment model, and send the risk type and modification suggestions to the control center.

[0065] The risk types can refer to the specific risk factors identified in the contract. For example, it can include legal risks: such as contract terms not conforming to relevant laws and regulations. Financial risks: such as unreasonable payment terms leading to potential financial losses. Time risks: such as unclear project completion time, which may cause delays. Performance risks: such as the risk that one party to the contract fails to fulfill its obligations.

[0066] The modification suggestions can be specific improvement suggestions for the contract content to reduce the identified risks. It can include legal risks: suggesting consulting a legal advisor to modify the non-compliant terms. Financial risks: suggesting re-evaluating the payment conditions and adding a margin clause. Time risks: suggesting clarifying the project time nodes and adding a delay clause. Performance risks: suggesting adding a liability for breach of contract clause to ensure the rights and interests of both parties to the contract.

[0067] The control center can refer to a department or system responsible for supervising and managing contract risks.

[0068] When evaluating a contract, the model can perform label prediction on the contract to identify the risk types related to the contract. The model classifies based on the historical data learned during training. Based on the risk type identification by the model, corresponding modification suggestions are generated. Specifically, it can be achieved through the output layer design of the model to let the model output the modification suggestions. Then, the risk types and modification suggestions are sent to the control center via wireless communication technology.

[0069] S103, if the modified second decoration contract sent by the control center is received, transmit the second decoration contract to the blockchain platform.

[0070] The second decoration contract can refer to a revised version made according to the risk assessment results of the first decoration contract after being reviewed and modified by the control center. It usually includes changes, supplements, or deletions to the original contract content to reduce the contract risks or improve the contract enforceability. The second decoration contract should reflect the specific adjustments made by the control center based on the risk types and modification suggestions.

[0071] The blockchain platform can be a decentralized and distributed database system for securely storing and managing contract data. Through the blockchain, contract information can be jointly 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.

[0072] The system receives the modified second decoration contract sent by the control center. The contract content has been reviewed and modified, and the previously identified risks have been resolved. Then, using the API or smart contract interface provided by the blockchain platform, the data of the second decoration contract is sent to the blockchain. When sending the request, relevant metadata (such as timestamp, contract version, creator information, etc.) can be included for subsequent search and auditing. The blockchain platform will process the request and store the second decoration contract as a transaction record in the blockchain. The system can receive a confirmation message to verify that the contract has been successfully uploaded to the blockchain.

[0073] Based on the above technical solution, optionally, after transmitting the second decoration contract to the blockchain platform, the method further includes:

[0074] Continuously monitor the contract execution data of the second decoration contract through a preset smart contract;

[0075] If a key node is read, obtain the node type of the key node, determine the target operation according to the node type and the preset operation rules, and execute the target operation.

[0076] In this solution, the preset smart contract can refer to a contract program pre-written and deployed on the blockchain platform, containing code regarding contract terms, conditions, and execution logic. These smart contracts automatically run during the contract execution process to ensure that the contract terms are followed and reduce manual intervention.

[0077] The contract execution data can refer to all information related to the execution of the second decoration contract, including but not limited to project progress, payment records, quality inspection results, etc. These data can be used to monitor the execution situation and status of the contract.

[0078] The key node can refer to a time point or event that needs special attention during the contract execution process. For example, the project start date, payment node, and project completion date. These nodes are crucial for the smooth execution of the contract, and the system needs to continuously monitor the status of these nodes.

[0079] The node type can be the specific tasks or operations that each node needs to complete during the contract execution. Specifically, it can include the start node: Task: Confirm the project start and sign the start document. Mark the official start of the project and ensure that all parties understand and agree to the project start conditions. Payment node: Task: Process and confirm the payment. Ensure that the payment is completed within the agreed time to promote the project progress. Inspection node: Task: Conduct stage - by - stage quality inspections to ensure that the construction complies with the specifications. Discover problems in a timely manner and rectify them to avoid greater losses in the later stage. Document review node: Task: Submit and review the necessary documents (such as design plans, completion reports). Ensure the compliance and integrity of all relevant documents and avoid missing key documents. Change management node: Task: Submit, review, and confirm the contract change application. Manage the project scope change and ensure that all parties reach an agreement on it. Acceptance node: Task: Conduct the final acceptance to confirm that the project delivery meets the contract requirements. Ensure that the project is delivered according to the quality standards and meets all acceptance conditions.

[0080] The preset operation rules can include node completion confirmation: Ensure that each node completes its task within the specified time, such as confirming the project start, processing payments, etc. Automatic trigger condition: When a certain node is not completed on time, the smart contract automatically triggers the corresponding operation, such as sending a notice or warning. Compliance check: The operations of each key node need to 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 project progress.

[0081] The target operations can include sending a notice: When the start node is not completed, send a reminder to the relevant parties to urge the confirmation of the project start. Recording the payment: At the payment node, confirm the receipt of payment and update the contract status to ensure that the conditions relied on by subsequent nodes are met. Generating a quality inspection report: At the inspection node, generate a quality inspection report and record the results for subsequent review. Document submission: At the document review node, require the relevant parties to submit the necessary documents and conduct a review. Processing the change application: At the change management node, process the contract change request and confirm. Final acceptance: At the acceptance node, perform the final project inspection and confirm the delivery.

[0082] The smart contract can continuously collect contract execution data and monitor the status of key nodes in real - time. Once it reaches a key node, the system automatically reads the node type. According to the read node type, the system queries the preset operation rules to determine whether the target operation needs to be executed. If the operation conditions are met, the system executes the corresponding target operation (such as sending a notice, recording the payment, etc.) and updates the contract execution status. Then, the operation results are recorded on the blockchain platform to ensure transparency and immutability, and at the same time, the status is fed back to all relevant parties.

[0083] In this solution, by continuously monitoring the contract execution data, problems can be discovered in a timely manner to ensure that the project progresses as planned. Manual intervention is reduced, contract terms are automatically executed, efficiency is improved, and the error rate is reduced.

[0084] 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:

[0085] Continuously monitor the transaction status corresponding to each key node through a preset smart contract. If it is monitored that the transaction status is in the transaction completion state, obtain the transaction identification information, status update information, and attribute information;

[0086] Generate the second zero-knowledge proof corresponding to each key node through the preset smart contract according to the transaction identification information, status update information, and attribute information, and transmit the second zero-knowledge proof to the blockchain platform.

[0087] In this solution, the transaction status may refer to different stages in the execution process of the current transaction, such as "pending", "processing", "transaction completed", etc.

[0088] The transaction completion state may be when all conditions of the transaction are met and all necessary operations have been completed, and the transaction enters the "transaction completion state".

[0089] The transaction identification information may be an identifier that uniquely identifies a certain transaction, usually a string or a number, used to distinguish different transactions.

[0090] The status update information may be specific information describing the change of the transaction status, such as "changed from pending to transaction completed".

[0091] The attribute information may be additional information related to the transaction, such as the transaction amount, participants, timestamp, etc.

[0092] The second zero-knowledge proof may be a zero-knowledge proof generated based on the transaction identification information, status update information, and attribute information, aiming to verify certain information without disclosing the specific content.

[0093] A smart contract can be deployed on the blockchain to manage and monitor the transaction status. Triggers or events are set in the contract to monitor changes in the transaction status. For example, an event for the change of the status of a key node is set. The smart contract continuously listens for events related to each key node. Once the transaction status is updated, such as entering the "transaction completed status", the contract is triggered to execute the corresponding logic. Specifically, the unique identifier of the current transaction can be obtained, the information on the status change, such as "from pending to transaction completed", can be recorded, and other information related to the transaction, such as the parties involved and the transaction amount, can be collected. An algorithm for generating a second zero-knowledge proof is preset in the smart contract. This proof should be based on the obtained transaction identification information, status update information, and attribute information. The function for generating the zero-knowledge proof is called in the contract, and the collected information is input to generate a valid proof. Then the generated second zero-knowledge proof is recorded on the blockchain to ensure its immutability and traceability.

[0094] In this solution, the zero-knowledge proof allows the validity of the transaction to be verified without revealing specific information, thus protecting the privacy of users.

[0095] 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:

[0096] Monitoring the execution status information of each key node through a preset smart contract, and determining the target access policy and policy version information of each key node according to the execution status information and the preset access policy.

[0097] In this solution, the 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 the task completion status: indicating whether a certain key node (such as the payment node, acceptance node) has been completed. Timestamp: recording the start and end times of each key node to help monitor the progress. Responses of the parties involved: decisions or actions made by the parties involved at the key nodes, such as whether the payment has been confirmed. Results of compliance checks: confirming whether a certain node meets the preset standards or requirements, such as the results of quality inspections. Exception reports: recording any problems or delays that occur during the execution.

[0098] Key nodes and their corresponding execution status information can be defined in the smart contract, such as payment nodes, acceptance nodes, etc. Using blockchain technology, the execution status of each key node is recorded in real time, including task completion, timestamp, responses from participating parties, etc. When the status of a certain key node changes (such as task completion or delay), the smart contract automatically captures and updates the execution status information of this node. According to the preset access policy, the smart contract analyzes the current execution status information. It can include determining whether to allow access to relevant information or perform subsequent operations based on the node type and completion status. In the smart contract, according to the execution status and preset access policy, the target access policy for each key node is dynamically generated or adjusted, 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 participating parties follow the latest access rights and rules.

[0099] In this solution, the smart contract can automatically update and execute the access policy, reducing manual intervention and management costs.

[0100] Optionally, based on the above technical solution, after determining the target access policy and policy version information of each key node, the method further includes:

[0101] Regenerate the first public parameter, and regenerate the encryption key for each key node according to the first public parameter, the target access policy of each key node, and the execution status information;

[0102] Encrypt the contract information of each key node according to the encryption key to obtain the ciphertext information of the contract information of each key node, and embed the policy version information of each key node in the ciphertext information.

[0103] In this solution, based on the current environment and requirements, new first public parameters can be generated through the Trusted Setup phase. Specifically, it can include selecting new random group elements, updating the hash function, etc. According to the current execution status information and preset access policy, the target access policy of each key node is identified. Using the new first public parameter, 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 symmetric or asymmetric encryption algorithm). This process should ensure that the encryption key is combined with these input parameters, making it targeted. Using the generated encryption key, encrypt the contract information of each key node. This process will generate ciphertext information. In the generated ciphertext information, embed the policy version information of each key node. 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.

[0104] In this solution, by combining with the access policies of specific nodes, it is possible to flexibly control who can access which data. Only users who meet the conditions can decrypt the corresponding ciphertext, ensuring that the data is only accessible to authorized personnel. When the execution status or requirements change, regenerating the encryption key and access policies can quickly adapt to the new situation, improving the flexibility and responsiveness of the system.

[0105] S104, 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 the ciphertext information of the contract information, and transmit the ciphertext information to the blockchain platform.

[0106] The preset contract information extraction model can be an automated model used to extract key information from contract texts. This model can be based on natural language processing technology, and by analyzing the structure and content of the contract, extract important information such as contract terms, amounts, dates, and signing information of both parties. This information will be used for subsequent processing and analysis.

[0107] Contract information can refer to the set of all key information extracted from the second decoration contract. Specifically, it can include contract numbers, the two parties to the contract, contract amounts, start and end dates of the contract, main terms, and default terms.

[0108] The preset attribute encryption algorithm can be an encryption method that allows the encryption of contract information while defining who can decrypt and access this information according to specific access control policies. Attribute encryption ensures that even if the ciphertext is leaked, unauthorized users cannot obtain the plaintext information.

[0109] Ciphertext information can refer to the contract information that has been encrypted, and its content is unreadable to unauthorized users. The ciphertext is the result of encrypting the contract information through a preset attribute encryption algorithm and is used for secure storage and transmission.

[0110] The modified second decoration contract can be input into the preset contract information extraction model. The contract can be in 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. Then, the contract information is encrypted through 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 system calls or API interfaces. 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 relevant transaction information to ensure the immutability and traceability of the data.

[0111] S105, 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.

[0112] A first zero-knowledge proof can be used to prove the truth of a statement without revealing specific information. It allows one party (the prover) to prove to another party (the verifier) that they know a certain secret (such as contract information or ciphertext information) without disclosing the content of the secret. First zero-knowledge proofs are commonly used to enhance data privacy protection, ensuring that sensitive information is not directly exposed during data sharing or storage.

[0113] A suitable zero-knowledge proof protocol (such as zk-SNARKs or zk-STARKs) can be selected according to specific requirements. These protocols offer different performance and privacy protection features. Construct an instance of the zero-knowledge proof using the contract information and the ciphertext information. This typically involves 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 the ciphertext information but not their 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 blockchain through a smart contract or an API interface. Verify on the blockchain platform whether the zero-knowledge proof has been successfully stored and record the relevant transaction information to ensure its immutability and traceability.

[0114] In the embodiment of this application, receive the first decoration contract sent by the 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; if there is a contract risk, determine the risk type and modification suggestions through the preset risk assessment model, and send the risk type and modification suggestions to the control center; if receive the modified second decoration contract sent by the control center, transmit the second decoration contract to the blockchain platform; input the second decoration contract into a preset contract information extraction model to obtain contract information, and encrypt the contract information through a preset attribute encryption algorithm to obtain the 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. Through the above 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. Storing the contract and related information on the blockchain ensures the immutability of the data and enhances trust. Encrypting the contract information to protect sensitive information can ensure that only authorized parties can access it. Generating zero-knowledge proofs allows the validity of the contract to be proven without revealing the specific contract content, which can improve the privacy of data sharing.

[0115] Based on the above technical solution, optionally, the training steps of the preset risk assessment model include:

[0116] Obtain historical renovation contracts, label the risk score tags of the historical renovation contracts, and create a first data set according to the historical renovation contracts and the risk score tags;

[0117] Obtain historical risky renovation contracts, label the risk type tags and modification suggestion tags of the historical risky renovation contracts, and create a second data set according to the historical risky renovation contracts, the risk type tags and the modification suggestion tags;

[0118] Construct a risk assessment model, and train the risk assessment model according to the first data set and the second data set until the risk assessment model meets the preset risk assessment model standard.

[0119] In this solution, historical renovation contracts can be renovation contracts that have been completed or carried out in the past, and are usually used to analyze and evaluate risks. They contain detailed information about the project, such as contract amount, construction party, time arrangement, etc.

[0120] The risk score tag can be a quantitative index 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, project historical problems, construction quality, etc.

[0121] The first data set can be a data set composed of all historical renovation contracts and their corresponding risk score tags. 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.

[0122] Historical risky renovation contracts can refer to contracts that are identified as having risks in historical contracts. These contracts are usually accompanied by problems or disputes and require special attention.

[0123] The risk type tag can be used to identify the specific risk type in the historical risky renovation contract, such as quality risk, time delay risk, cost overrun risk, etc. This helps the model identify and classify different risks.

[0124] The modification suggestion tag can be a specific modification suggestion provided for the risk type identified in the historical risky renovation contract, such as modifying the contract terms, adjusting the payment arrangement, etc., to reduce the potential risk.

[0125] The second data set can be a data set composed of historical risky renovation contracts and their corresponding risk type tags and modification suggestion tags. This data set is used to help the model understand the relationship between the risk type and the coping strategy.

[0126] The preset risk assessment model criteria can refer to a series of metrics or thresholds used to evaluate the performance of the model, such as accuracy, recall, F1-score, etc. The model needs to meet these criteria to be considered effective.

[0127] Historical renovation contracts can be extracted from company archives, databases, or other storage systems. Experts or a team evaluate the potential risks of each contract based on the contract content and give a score (e.g., a rating from 1 to 5). Record the scores in a dataset and associate them with the corresponding contract information. Combine all historical renovation contracts with their risk score labels to form a structured dataset (the first dataset). Screen out the contracts with risk scores higher than a certain threshold from the first dataset to form a set of historical risky renovation contracts. Analyze each historical risky renovation contract and label the specific risk types (such as delays, quality, etc.). Provide possible modification suggestions for each contract according to the risk types to reduce risks. Combine the historical risky renovation contracts with their risk type labels and modification suggestion labels to form the second dataset. Then select a suitable machine learning model (such as decision tree, random forest, or neural network) for risk assessment. Divide the first dataset and the second dataset into training sets and test sets. Use the training set data to train the model, and at the same time adjust the model parameters and perform cross-validation. Use the test set to evaluate the model performance and calculate metrics such as accuracy and recall. Set specific evaluation metrics, such as accuracy, F1-score, etc., as the criteria for the model to be qualified. Optimize the model according to the evaluation results, adjust the parameters, and retrain until the model meets the preset criteria.

[0128] In this solution, using historical data for modeling makes the risk assessment more objective and reliable, avoiding the bias of human subjective judgment. The systematic method helps identify potential risks, improves the predictability of problems in renovation contracts, and reduces uncertainties in projects.

[0129] Based on the above technical solution, optionally, the training steps of the preset contract information extraction model include:

[0130] Obtain historical renovation contracts, label the contract information labels of the historical renovation contracts, and construct a third dataset according to the historical renovation contracts and the contract information labels;

[0131] Construct a contract information extraction model, and train the contract information extraction model according to the third dataset until the contract information extraction model meets the preset contract information extraction model training criteria.

[0132] In this solution, the contract information labels can be the annotations of key information in historical renovation contracts, 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.

[0133] The third data set can be a set consisting of historical decoration contracts and their corresponding contract information tags. Each piece of data contains a historical contract text and its annotated contract information, usually stored in a structured form, such as CSV, JSON, etc., for easy model training.

[0134] The preset training criteria for the contract information extraction model can include evaluation metrics such as the accuracy, recall rate, and F1 score of the model. These criteria set the performance levels required for the model during the training and validation phases to ensure that the model can effectively extract contract information.

[0135] It is possible to collect the enterprise's past decoration contracts, ensuring 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 item by item to ensure that the key information in the contracts is accurately identified. Annotation tools can be used to improve efficiency. Organize the annotated contracts and their corresponding tags into a third data set, ensuring data cleaning and formatting for subsequent model training. Select appropriate machine learning or deep learning algorithms (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 model performance on the validation set, calculate metrics such as accuracy, recall rate, and F1 score, and ensure that the model meets the preset training criteria. According to the evaluation results, optimize the model architecture or training process, and add training data for retraining as needed until the preset criteria are met.

[0136] In this solution, through model training, human errors can be reduced, ensuring the accuracy and consistency of information extraction. The time for manual review and extraction of contract information can be reduced, improving work efficiency.

[0137] Embodiment 2

[0138] Figure 2 is a schematic flowchart of the method for risk assessment and encryption management of decoration contracts based on blockchain provided in Embodiment 2 of this application, as Figure 2 shown, and the specific method includes the following steps:

[0139] S201, obtain the preset access policy and the initial status information of the second decoration contract, and determine the target access policy according to the initial status information and the preset access policy; wherein, the preset access policy includes policy version information.

[0140] The preset access policy can be a predefined set of rules that specify which users or systems can access specific data or resources, usually including user roles, permissions, and conditions, etc.

[0141] The initial state information can refer to the initial data related to the second decoration contract, such as the contract creation time, the identities of the relevant parties, the contract status, etc. This information provides context for subsequent processing and decision-making.

[0142] The target access policy can be a policy dynamically generated based on the initial state information and a preset access policy, specifically describing which users or systems can access the encrypted contract information in the current context, and may consider the current contract status and the roles of the parties involved.

[0143] The policy version information can refer to the version number or identifier of the access policy, used to track and manage different versions of the access policy to ensure the correct rules are used during the encryption and decryption processes.

[0144] It can be obtained through system configuration or database calls, usually defined during system initialization, including roles, permissions, and access conditions. Extracting the initial state information from the contract management system can include the contract creation date, party information, current status, etc. Evaluate the current contract status and the identities of the relevant parties to determine who should have access to the contract information. Combine the preset access policy with the initial state information to generate a specific target access policy, which may contain specific conditions and restrictions.

[0145] S202, generate the first public parameter, and generate an encryption key according to the first public parameter, the target access policy, and the initial state information.

[0146] The first public parameter can refer to a set of public parameters generated during the encryption process, usually including 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.

[0147] The encryption key can be generated based on the first public parameter, the target access policy, and the initial state information, and is used to encrypt the contract information. It ensures that only users meeting specific conditions can decrypt and access the contract content.

[0148] A secure random number generation algorithm can be used to generate the first public parameter according to preset security parameters. These parameters usually include group elements, random numbers, etc. required by the encryption algorithm. Use the first public parameter, the target access policy, and the initial state information as inputs, and use a predetermined algorithm to generate the encryption key. This step ensures that the generated key is associated with specific access requirements and the contract status.

[0149] S203, encrypt the contract information according to the encryption key to obtain ciphertext information, and embed the policy version information in the ciphertext information.

[0150] The generated encryption key can be used to encrypt the information of the second decoration contract to obtain ciphertext information. Finally, policy version information is added to the ciphertext information to ensure the correct access policy is used during decryption.

[0151] In this embodiment, encrypting the 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, enabling the system to adapt to different access requirements and environmental changes.

[0152] Embodiment Three

[0153] Figure 3 is a schematic flowchart of the method for risk assessment and encryption management of decoration contracts based on blockchain provided in Embodiment Three of this application. As Figure 3 shown, the specific method includes the following steps:

[0154] S301, Receive the data acquisition request from the client, determine the user attribute information according to the data acquisition request, and generate zero-knowledge proof challenge information, and send the zero-knowledge proof challenge information to the client.

[0155] The data acquisition request can be a request initiated by the client to the server, usually including the identifier of the specific data to be accessed and access permission requirements. Specifically, it can include the identity information of the requester, the type of data required, the reason for access, etc.

[0156] The user attribute information can be a set of data describing the user's characteristics, used to determine the user's access rights. Specifically, it can include the user role (such as administrator, ordinary user), permission level (such as can view, edit or delete data), access history (such as files or contracts accessed in the past), etc.

[0157] The zero-knowledge proof challenge information can be a request information used to require the client to prove that it has certain knowledge (such as a key) without directly disclosing the knowledge.

[0158] A request from the client can be received, usually including the type of data to be accessed and the required node information. The request can contain the user's identity identifier for subsequent confirmation of the user's attribute information. According to the user identity identifier in the client request, the system queries the user's attribute information, such as role, permission level, etc. These attribute information are used to determine whether the user has the right to access the requested data. The system generates zero-knowledge proof challenge information according to the user's attribute information and access request. This information is used to verify whether the user has the access permission without disclosing the specific attribute information. Then the generated zero-knowledge proof challenge information is sent to the client, and the client needs to use this information to generate the corresponding third zero-knowledge proof.

[0159] S302, receive the third zero-knowledge proof generated by the client based on the zero-knowledge proof challenge information, determine the target key node and the target access policy according to the data acquisition request, and obtain the second zero-knowledge proof corresponding to the target key node.

[0160] 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 permission to access specific data).

[0161] The target key node can be a specific node that the user hopes to access or operate during the contract execution or data flow. These nodes usually correspond to the key steps or events of the contract. It can include specific contract terms, payment nodes, quality inspections, document reviews, change management, etc., which are all key points that the user needs to pay attention to or obtain information about.

[0162] The client generates the third zero-knowledge proof based on the received challenge information and sends it back to the system. This proof indicates that the user meets the conditions of the access request according to its attribute information. The system parses the data acquisition request and determines the target key node that the user hopes to access and the relevant target access policy from it. According to the determined target key node, the system retrieves the second zero-knowledge proof of this node. This proof shows that this node complies with the preset access policy.

[0163] S303, verify whether the third zero-knowledge proof meets the preset challenge conditions according to the first zero-knowledge proof and the second zero-knowledge proof.

[0164] The first zero-knowledge proof (previously generated) and the second zero-knowledge proof can be used to verify the third 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 its access permission.

[0165] The preset challenge conditions can refer to the specific conditions that the system requires to be met during the zero-knowledge proof process. These conditions can 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 permission to access the target key node. Ensure that the user attribute information is consistent with the target access policy.

[0166] S304, if it meets the preset challenge conditions, generate the second public parameter, generate the decryption key according to the user attribute information, the target access policy, the execution status information and the second public parameter, and send the decryption key to the client.

[0167] The second public parameter can 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 can include randomly generated group elements, hash values related to specific access policies.

[0168] The decryption key is the key used to convert ciphertext information back into plaintext information. The process of generating the decryption key is based on the user's attribute information, the target access policy, the execution status information, and the second public parameter.

[0169] The client can refer to a user or application that interacts with the system. It can be a mobile application, a web application, or any program that supports communication with the server. The client is responsible for: sending data acquisition requests, receiving the decryption key and other necessary information, and interacting with the backend smart contract or blockchain system to access protected contract information.

[0170] If the third zero-knowledge proof passes the verification, the system generates the second public parameter, which is required for further processing. Then, using the user attribute information, the target access policy, the execution status information, and the second public parameter, the system generates the 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.

[0171] In this embodiment, through zero-knowledge proof, the user 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.

[0172] Embodiment 4

[0173] Figure 4 It is a schematic structural diagram of a blockchain-based decoration contract risk assessment and encryption management system provided by Embodiment 4 of the present application. As Figure 4 shown, this system is used to implement the method of a blockchain-based decoration contract risk assessment and encryption management system provided by Embodiments 1, 2, and 3. Specifically, this system includes the following:

[0174] A risk determination module 401, 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;

[0175] An evaluation module 402, configured to, if there is a contract risk, determine the risk type and modification suggestions through a preset risk assessment model, and send the risk type and modification suggestions to the control center;

[0176] A transmission module 403, configured to, if receiving a modified second decoration contract sent by the control center, transmit the second decoration contract to the blockchain platform;

[0177] An encryption module 404 is configured 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;

[0178] A zero-knowledge proof generation module 405 is configured 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.

[0179] In the embodiment of the present application, a risk determination module is 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 evaluation module is configured to, if there is a contract risk, determine a risk type and a modification suggestion through a preset risk assessment model, and send the risk type and the modification suggestion to the control center; a transmission module is configured to, if receiving the modified second decoration contract sent by the control center, transmit the second decoration contract to the blockchain platform; an encryption module is configured 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; a zero-knowledge proof generation module is configured 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. Through the above 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. Storing the contract and related information on the blockchain ensures the immutability of data and enhances trust. Encrypting the contract information to protect sensitive information can ensure that only authorized parties can access it. Generating zero-knowledge proofs allows the validity of the contract to be proven without disclosing the specific contract content, which can improve the privacy of data sharing.

[0180] The above is only the preferred embodiment of the present application and the technical principles applied. The present application is not limited to the specific embodiments described here. Various obvious changes, re-adjustments and substitutions that can be made by those skilled in the art will not depart from the protection scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments. Without departing from the concept of the present application, it may also include more other equivalent embodiments, 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; 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; Monitor the execution status information of each key node through a preset smart contract, and determine the target access strategy and strategy version information of each key node based on the execution status information and the preset access strategy; 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; Encrypting the contract information of each key node according to the encryption key to obtain ciphertext information of the contract information of each key node, and embedding the policy version information of each key node in the ciphertext information; 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; 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.

2. According to the blockchain-based renovation contract risk assessment and encryption management method of claim 1, it 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.

3. 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.

4. 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.

5. 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.

6. 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, 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, for transmitting the second decoration contract to the blockchain platform upon receiving the modified second decoration contract sent by the control center; The system is also used to: 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; Monitor the execution status information of each key node through a preset smart contract, and determine the target access strategy and strategy version information of each key node based on the execution status information and the preset access strategy; 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; Encrypting the contract information of each key node according to the encryption key to obtain ciphertext information of the contract information of each key node, and embedding the policy version information of each key node in the ciphertext information; 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; A zero-knowledge proof generation module, 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; The system is also used to: 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.

Images