A credit information security protection method based on a blockchain work mechanism

Abstract

This invention discloses a method for protecting credit information security based on a blockchain proof-of-work mechanism, belonging to the field of credit information security technology. It aims to solve problems in existing credit information protection methods, such as high centralization risk, significant tampering risks, insufficient decentralization, and lax access control. The method includes: building a consortium blockchain network based on proof-of-work; collecting credit information and performing anonymization, standardization, and integrity preprocessing; packaging standardized credit information into candidate transaction blocks, generating and allocating proof-of-work tasks; after verification nodes complete the proof-of-work calculation, all nodes in the network perform consensus verification; after reaching consensus, storing the transaction blocks on the blockchain and using asymmetric encryption to protect sensitive information; achieving full lifecycle security protection for credit information and improving the reliability and practicality of credit information protection.

Description

Technical Field

[0001] This invention belongs to the field of credit information security technology, specifically a method for protecting credit information security based on the blockchain workload mechanism. Background Technology

[0002] With the rapid development of financial technology, credit business is gradually transforming towards digitalization and networking. As a core data asset of the financial system, credit information contains sensitive content such as the identity information, financial information, and repayment records of credit entities. Its security protection is directly related to personal privacy, corporate trade secrets, and the stability of the financial system.

[0003] Currently, credit information storage and management mainly adopt a centralized database model, which has many security risks: on the one hand, centralized databases have a single point of failure. Once the database is attacked or leaked, a large amount of credit information will be leaked, causing huge losses to credit entities and financial institutions; on the other hand, under the centralized management model, the risk of tampering and forgery of credit information is high. Some institutions may arbitrarily modify credit records, affecting the fairness and authenticity of credit business.

[0004] Currently, some technologies have applied blockchain to credit information management, but most of them use consensus mechanisms such as proof of stake and delegated proof of stake. Although these mechanisms consume less computing power, they are not sufficiently decentralized and are prone to situations where a few nodes monopolize the right to record transactions, which in turn leads to the risk of credit information being tampered with or manipulated.

[0005] Therefore, this invention provides a method for protecting credit information security based on a blockchain workload mechanism. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0007] The technical solution adopted by this invention to solve its technical problem is: a method for protecting credit information security based on a blockchain workload mechanism, comprising the following steps: S1: Build a consortium blockchain network based on proof-of-work. The consortium blockchain network includes credit institution nodes, regulatory nodes, credit investigation nodes and verification nodes. Each node deploys the same blockchain ledger and proof-of-work algorithm, and sets a threshold for the difficulty of work calculation and consensus verification rules. S2: Collect the original credit information of the credit subject, including the credit subject's identity information, credit application information, repayment record information and credit reference information; The original credit information is anonymized, standardized in format, and validated for completeness to obtain standardized credit information. S3: Package the standardized credit information into candidate transaction blocks, generate summary information of the candidate transaction blocks based on a preset hash algorithm, dynamically adjust the workload calculation difficulty in combination with the computing power of the blockchain network, generate a proof-of-work task, and broadcast the candidate transaction blocks and the proof-of-work task to all verification nodes in the consortium blockchain network. S4: After receiving the proof-of-work task, each verification node continuously calculates random numbers to ensure that the hash value of the combination of the candidate transaction block digest information and the random numbers meets the preset difficulty threshold, thus completing the proof-of-work. The verification node broadcasts the completed proof-of-work results and candidate transaction blocks to the entire network. Each node verifies the validity of the proof-of-work results and verifies the completeness and compliance of the credit information in the candidate transaction blocks. When more than a preset proportion of nodes pass the verification, a consensus is reached across the entire network. S5: Write the candidate transaction block into the blockchain ledger to form an immutable credit information block. At the same time, use an asymmetric encryption algorithm to encrypt the sensitive credit information in the credit information block. Each node can only access the decrypted sensitive information with its corresponding private key. S6: Establish an access permission mechanism based on proof-of-work. Accessing nodes need to complete a lightweight proof-of-work with a preset difficulty level. Only after successful verification can they submit an access request. The system allocates the corresponding access scope according to the identity and permissions of the accessing nodes. At the same time, the blockchain's chain structure is used to realize the full-process traceability of credit information and to query the collection, processing, on-chain and access records of credit information in real time. S7: When monitoring for abnormal computing power, forged proof-of-work, unauthorized access, or signs of credit information tampering, trigger an anomaly warning, suspend the transactions and access permissions of the relevant nodes, and start backup nodes to supplement computing power.

[0008] The proof-of-work algorithm uses the SHA-256 hash algorithm. The difficulty threshold for work calculation is dynamically adjusted according to the real-time computing power of the consortium blockchain network, with an adjustment cycle of every 2016 blocks.

[0009] The desensitization process specifically involves: partially replacing and hiding characters in the credit subject's ID card number, mobile phone number, and bank card number, and blurring the credit subject's address and workplace. The integrity verification specifically involves verifying whether the original credit information contains required fields, whether the field format conforms to preset standards, and whether missing or abnormal fields need to be returned to the credit institution node for supplementation and improvement before reprocessing.

[0010] The structure of the candidate transaction block includes a block header and a block body. The block header contains the hash value of the previous block, the timestamp of the current block, the workload difficulty value, a random number placeholder, and a credit information digest. The block contains standardized credit information, credit institution node signatures, and preprocessed logs. The proof-of-work task includes candidate transaction block summaries, difficulty thresholds, and calculation rules.

[0011] The specific process of the workload calculation is as follows: the verification node obtains the candidate transaction block digest information, initializes a random number, performs SHA-256 double hash calculation on the combination of the digest information and the random number, and if the first N bits of the calculation result are 0, where N is the number of bits corresponding to the difficulty threshold, then the proof of work is completed; otherwise, iteratively update the random number and repeat the hash calculation until the condition is met. The preset ratio for consensus verification is more than 2 / 3 of the total number of nodes in the network.

[0012] The asymmetric encryption algorithm uses the RSA algorithm. Credit institution nodes hold private keys and are responsible for encrypting and decrypting sensitive credit information. Regulatory nodes and credit reporting nodes hold corresponding public keys and can only access encrypted credit information or non-sensitive information that has been decrypted after authorization. The blockchain ledger uses distributed storage, with each node storing a complete copy of the ledger.

[0013] The difficulty threshold of the lightweight proof of work is 1 / 10 of the difficulty threshold of the normal proof of work, and the time for the access node to complete the lightweight proof of work does not exceed 10 seconds. The access permissions are divided into three levels: Level 1 permissions can only access credit information summaries, Level 2 permissions can access non-sensitive credit information, and Level 3 permissions can access complete sensitive credit information. The permission level is jointly reviewed and allocated by the credit institution node and the regulatory node.

[0014] The anomaly monitoring indicators include: a single node's computing power accounts for more than 50% of the total network computing power, the hash value of the proof-of-work result does not meet the difficulty threshold, the access request does not complete the lightweight proof-of-work, and the block hash value does not match the previous block hash value. After an anomaly is handled, the anomaly information and handling results are packaged into a new transaction block, and stored on the blockchain after proof-of-work is completed.

[0015] The consortium blockchain network also includes backup nodes, which synchronize blockchain ledger data in real time. When verification nodes or credit institution nodes fail, backup nodes automatically start to take over the corresponding workload calculation, information verification and access response tasks, ensuring the continuity of the protection method.

[0016] The credit information includes personal credit information and corporate credit information. For corporate credit information, additional data collection and verification of corporate operating conditions and asset-liability status are required. Furthermore, the workload calculation threshold for corporate credit information is higher than that for personal credit information to ensure the security of corporate credit information. The beneficial effects of this invention are as follows: 1. The present invention discloses a method for protecting credit information security based on a blockchain proof-of-work mechanism. This invention uses a proof-of-work mechanism to build a consortium blockchain network, abandoning the traditional centralized database model. Each node stores credit information in a distributed manner, avoiding single points of failure. At the same time, the right to record transactions is obtained through computing power competition. Malicious nodes need to control more than 51% of the computing power of the entire network to tamper with credit information, making the attack cost extremely high. This method can effectively prevent security risks such as hacker attacks and information leakage, significantly improve the anti-attack capability and security of credit information, solve the security shortcomings of the existing centralized model, and avoid the problem of a few nodes monopolizing the right to record transactions by utilizing the fully decentralized characteristics. 2. The present invention provides a method for protecting credit information security based on a blockchain proof-of-work mechanism. Through this mechanism, credit information, after being packaged into blocks, must be verified by all nodes in the network before being uploaded to the blockchain. Blocks are linked to previous blocks via hash values, forming an immutable chain structure. If credit information is tampered with, the block hash value will change, which can be quickly detected by all nodes in the network. Simultaneously, the blockchain ledger records the entire process of credit information collection, processing, uploading, and access, enabling traceability of credit information, facilitating verification by regulatory nodes, ensuring the fairness and authenticity of credit transactions, and solving the problems of high risk of credit information tampering and difficulty in traceability in existing technologies. 3. The credit information security protection method based on blockchain workload mechanism described in this invention uses an asymmetric encryption algorithm to encrypt sensitive credit information and combines it with a hierarchical access permission mechanism. Different nodes access different ranges of credit information according to their permissions. At the same time, the accessing node must complete a lightweight workload proof before submitting an access request. This provides double protection for the access security of credit information, prevents the leakage and abuse of sensitive information, and balances information security and access convenience, achieving the security goal of "data is usable but not visible". 4. The credit information security protection method based on blockchain workload mechanism described in this invention dynamically adjusts the workload calculation difficulty according to the real-time computing power of the blockchain network to ensure stable block generation time. This ensures the security of workload calculation while avoiding excessive computing power consumption that affects processing efficiency. At the same time, the access process adopts lightweight proof-of-work, which improves access efficiency while ensuring access security, meets the actual application needs of credit business, and solves the problems of excessive computing power consumption and low efficiency in the application of existing mechanisms. 5. The present invention provides a method for protecting credit information security based on a blockchain workload mechanism. This invention achieves end-to-end security protection from the collection, preprocessing, on-chaining, and storage of credit information, to access, tracing, and anomaly handling. Each step is equipped with security verification and protection mechanisms to ensure the security and integrity of credit information throughout its entire lifecycle. Simultaneously, the use of backup nodes ensures the continuity of the protection method, preventing information loss or service interruption due to node failures, further enhancing the reliability and practicality of the solution and effectively addressing various risks in credit information security protection. 6. The credit information security protection method based on the blockchain workload mechanism described in this invention realizes the collaboration of multiple nodes such as credit institutions, regulatory departments, and credit reporting agencies through the construction of a consortium blockchain network. The distributed storage mode enables each node to synchronously obtain compliant credit information, breaking the data silo problem in traditional credit information management. At the same time, through encryption technology and access control, the security and compliance of information sharing are ensured, and the collaborative efficiency of credit business is improved. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0019] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0020] Example 1: A method for protecting credit information security based on blockchain proof-of-work mechanism is proposed. A consortium blockchain network based on proof-of-work is built. The participating nodes include 3 commercial banks (credit institution nodes), 1 regulatory agency (regulatory node), 1 credit reporting agency (credit reporting node), and 10 verification nodes. Each node deploys the same blockchain ledger and SHA-256 proof-of-work algorithm. The initial workload calculation difficulty threshold is set to have the first 18 bits of the hash value as 0. The difficulty adjustment cycle is every 2016 blocks. The preset block generation time is 8 minutes. The consensus verification ratio is more than 2 / 3 of the total number of nodes in the network, that is, at least 11 nodes must pass the verification. The consortium blockchain network is deployed using a dedicated network. Node access requires identity authentication to ensure the security and closed nature of the network and prevent malicious external nodes from accessing it.

[0021] Commercial bank nodes collect original credit information from individual credit subjects, including: name, ID number, mobile phone number, bank card number, loan application amount, repayment period, repayment method, personal credit report, income certificate, etc. Preprocess the original credit information: for example, replace the ID number with "110101********1234", the mobile phone number with "138****5678", the bank card number with "622202********1234", and only retain "Chaoyang District, Beijing" for the address, without retaining the specific street and house number, so as to achieve de-identification.

[0022] Convert all information to JSON format, and unify field names (e.g., "ID number" should be "id_card", "credit amount" should be "credit_amount") to ensure consistent formatting; The verification revealed that the personal credit information was missing the "income verification number" field. The information was then returned to the commercial bank node for supplementation. After the supplementation was completed, the information was reprocessed to obtain standardized personal credit information. After the preprocessing was completed, the commercial bank node signed and confirmed the standardized information to ensure the authenticity of the information source.

[0023] Commercial bank nodes package standardized personal credit information into candidate transaction blocks, the structure of which is as follows: Block header: previous block hash (0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef), current block timestamp, workload difficulty (18), random number placeholder (0), credit information digest (calculated from the block body using the SHA-256 algorithm, 0x9876543210fedcba9876543210fedcba9876543210fedcba9876543210fedcba); Block body: Standardized personal credit information, commercial bank node signature (0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890), preprocessing log (records the de-identification and verification process); Based on the current computing power status of the blockchain network, the commercial bank node determines that the current workload difficulty threshold remains unchanged at 18, generates a proof-of-work task (including candidate transaction block digests, difficulty threshold of 18, calculation rule: SHA-256 double hash calculation, with the first 18 bits of the result being 0), and broadcasts the candidate transaction blocks and proof-of-work task to all 10 verification nodes in the consortium blockchain network.

[0024] After receiving the proof-of-work task, each verification node starts computing power to calculate the work: the initial random number is 0, and a SHA-256 double hash calculation is performed on the combination of the candidate transaction block digest and the random number. If the first 18 bits of the calculation result are not 0, the random number is iteratively updated (in sequence 1, 2, 3...), and the hash calculation is repeated; when a verification node calculates the random number to be 123456, the hash calculation result is "0000000000000000000abcdef1234567890abcdef1234567890abcdef", with the first 18 bits being 0, thus completing the proof-of-work. The verification node broadcasts the proof-of-work result (random number 123456, hash result) and candidate transaction blocks to the entire network. Each node (3 commercial banks, 1 regulatory agency, 1 credit reporting agency, and 10 verification nodes, for a total of 15 nodes) verifies the validity of the proof-of-work result (recalculates the hash value and confirms that the first 18 bits are 0), and at the same time verifies the integrity and anonymization compliance of the personal credit information in the candidate transaction blocks. After verification, 13 nodes passed the verification (more than 2 / 3 of the 10 nodes), achieving network-wide consensus. The two nodes that failed verification did not complete the verification due to insufficient computing power, and their verification results were automatically ignored by the system to ensure the effectiveness of the consensus process.

[0025] After reaching a consensus, candidate transaction blocks are written into the blockchain ledger to form an immutable personal credit information block. The hash value of this block is “000000000000000000abcdef1234567890abcdef1234567890abcdef”, which is associated with the hash value of the previous block to form a chain structure. The RSA algorithm is used to encrypt sensitive personal credit information (such as complete ID card number, mobile phone number, and bank card number) in the block. Commercial bank nodes hold private keys (used for encryption and decryption), while regulatory nodes and credit reporting nodes hold public keys (they can only access the encrypted information; if they need to access the complete sensitive information, they need to apply for authorization from the commercial bank nodes and obtain temporary decryption permissions). The blockchain ledger uses distributed storage, with each of the 15 nodes storing a complete copy of the ledger. This ensures that the availability of personal credit information is not affected even if a single node fails (such as a verification node going down). Simultaneously, the nodes synchronize ledger data in real time to ensure data consistency.

[0026] The credit reporting node needs to access the individual's credit information. It submits an access request and first completes a lightweight proof-of-work (difficulty threshold of 2, i.e., the first two bits of the hash value are 0). The credit reporting node then starts computing power calculation and completes the proof-of-work within 1 second (random number is 789, hash result is "00abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef"). The verification is successful. The system assigns secondary access permissions based on the identity of the credit reporting node (access to non-sensitive personal credit information, such as loan amount, repayment period, and credit report summary, but not access to complete sensitive information). If a regulatory node needs to verify the entire process of an individual's credit information, it can query the blockchain ledger to: collection records (collected by the commercial bank node on March 3, 2026 at 08:30:00), preprocessing records (preprocessing completed at 08:40:00), on-chain records (on-chain completed at 09:10:00), and access records (accessed by the credit reporting node at 09:15:00), achieving full-process traceability. Access records are automatically written to the blockchain, are tamper-proof, and facilitate subsequent verification.

[0027] Each node monitors the blockchain network status in real time. If the computing power of a certain verification node reaches 55% (exceeding 50% poses a risk of a 51% computing power attack), an anomaly warning is immediately triggered. The system suspends the transaction and access permissions of that verification node and starts two backup nodes to supplement computing power and maintain the overall network computing power balance. The abnormal information (abnormal node ID, computing power ratio, warning time) and the handling results (suspension of permissions, activation of backup node) are packaged into a new transaction block. After the proof-of-work is completed (difficulty threshold 18), it is stored on the blockchain to achieve traceability of abnormal behavior and facilitate subsequent verification of the abnormal node's behavior by regulatory nodes. During the abnormal handling process, the blockchain network operates normally and does not affect the storage and access of personal credit information.

[0028] Example 2: Using the consortium blockchain network from Example 1, two new corporate lending institution nodes are added, increasing the number of verification nodes to 15, for a total of 20 nodes. The initial difficulty threshold for calculating corporate lending information is set to have the first 20 bits of the hash value as 0 (higher than the 18 bits for personal lending information). The difficulty adjustment cycle remains every 2016 blocks, the preset block generation time is 10 minutes, and the consensus verification ratio is more than 2 / 3 of the total number of nodes in the network (i.e., at least 14 nodes must pass verification). Corporate lending nodes must undergo additional corporate qualification verification to ensure the legality and reliability of the nodes.

[0029] The enterprise credit institution node collects the original credit information of a small and medium-sized enterprise, including: enterprise name, unified social credit code, legal representative information, enterprise operating status (revenue and profit in the past 3 years), asset and liability status, loan application amount (2 million yuan), repayment period (5 years), guarantee information, enterprise credit report, etc. The process involves several steps: anonymization (hiding the middle 8 digits of the Unified Social Credit Code and the middle 4 digits of the legal representative's mobile phone number), format standardization (converting to JSON format and standardizing field names), and integrity verification (adding the missing "Guarantee Institution Number" field). Additional verification of the company's operating status and asset-liability situation is also performed (verifying that revenue and profit data match the company's financial statements). This results in standardized corporate credit information. The corporate credit institution node signs and confirms the standardized information and submits it to the regulatory node for preliminary review. Once approved, the process proceeds to the next step.

[0030] Corporate credit institution nodes package standardized corporate credit information into candidate transaction blocks. The block header includes the hash value of the previous block, the current timestamp, the workload difficulty value of 20, a random number placeholder, and a summary of corporate credit information. The block body includes standardized corporate credit information, the signature of the corporate credit institution node, preprocessing logs, and preliminary review opinions from regulatory nodes. Based on the current total network computing power (1500 H / s), the workload difficulty threshold is dynamically adjusted to 20 (maintaining the initial value), a proof-of-work task is generated, and broadcast to 15 verification nodes. An additional specific verification rule for enterprise credit information is added to the proof-of-work task to ensure the authenticity of enterprise operating data.

[0031] Each verification node initiates computing power to calculate the workload. Through iterative random number generation, when the random number reaches 987654, the first 20 bits of the hash calculation result are 0, completing the proof-of-work. The verification nodes broadcast the results to the entire network. 16 out of the 20 nodes pass the verification (more than 2 / 3), reaching a consensus. Simultaneously, the authenticity and compliance of the enterprise's credit information are verified, and no anomalies are found. The verification results of the 4 nodes that failed the verification are invalid because they did not complete the specific verification of the enterprise's operating data.

[0032] Candidate transaction blocks are written into the blockchain ledger, using the RSA algorithm to encrypt sensitive corporate information (such as a complete balance sheet and complete information about the legal representative). Corporate credit institution nodes hold private keys, regulatory nodes hold the highest-level public key (allowing access to complete sensitive information), and credit reporting nodes hold secondary-level public keys (allowing access to non-sensitive information). Each node stores a complete copy of the ledger, ensuring the availability and security of corporate credit information. Simultaneously, blocks containing corporate credit information are specially marked for easy subsequent retrieval and monitoring.

[0033] The regulatory node needs to access the complete sensitive information of the enterprise's credit information, complete the lightweight proof of work (difficulty threshold of 3), and after the verification is passed, it will be assigned a three-level access permission, which can access all enterprise credit information; The entire process of the company's credit information can be traced through the blockchain ledger: data collection (March 3, 2026, 10:00:00), preprocessing (10:20:00), preliminary regulatory review (10:30:00), on-chain recording (10:50:00), and access records (accessed by the regulatory node at 11:00:00), ensuring the transparency and regulatory oversight of the company's credit business. The access records detail the access nodes, access times, and access content for easy subsequent verification.

[0034] The system detected that the proof-of-work result submitted by a certain corporate credit institution node was forged (the first 20 bits of the hash value were not 0), which immediately triggered an anomaly warning and suspended the node's on-chain permissions. Upon investigation, it was found that the node attempted to tamper with the corporate credit amount (changing 2 million yuan to 3 million yuan). A backup corporate lending institution node was activated to take over its business. Abnormal information and handling results (suspension of permissions, content tampering, and verification results) were packaged and uploaded to the blockchain to ensure traceability of abnormal behavior. Subsequently, this node must complete compliance rectification and re-authenticate its identity before its permissions can be restored. During the abnormal handling process, the corporate lending information was not tampered with, and the network operated normally.

[0035] The terms "front," "back," "left," "right," "top," and "bottom" all refer to the figures in the accompanying drawings. Figure 1 Based on the perspective of the observer, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0036] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for protecting credit information security based on a blockchain work mechanism, characterized in that, Includes the following steps: S1: Build a consortium blockchain network based on proof-of-work. The consortium blockchain network includes credit institution nodes, regulatory nodes, credit investigation nodes and verification nodes. Each node deploys the same blockchain ledger and proof-of-work algorithm, and sets a threshold for the difficulty of work calculation and consensus verification rules. S2: Collect the original credit information of the credit subject, including the credit subject's identity information, credit application information, repayment record information and credit reference information; The original credit information is anonymized, standardized in format, and validated for completeness to obtain standardized credit information. S3: Package the standardized credit information into candidate transaction blocks, generate summary information of the candidate transaction blocks based on a preset hash algorithm, dynamically adjust the workload calculation difficulty in combination with the computing power of the blockchain network, generate a proof-of-work task, and broadcast the candidate transaction blocks and the proof-of-work task to all verification nodes in the consortium blockchain network. S4: After receiving the proof-of-work task, each verification node continuously calculates random numbers to ensure that the hash value of the combination of the candidate transaction block digest information and the random numbers meets the preset difficulty threshold, thus completing the proof-of-work. The verification node broadcasts the completed proof-of-work results and candidate transaction blocks to the entire network. Each node verifies the validity of the proof-of-work results and verifies the completeness and compliance of the credit information in the candidate transaction blocks. When more than a preset proportion of nodes pass the verification, a consensus is reached across the entire network. S5: Write the candidate transaction block into the blockchain ledger to form an immutable credit information block. At the same time, use an asymmetric encryption algorithm to encrypt the sensitive credit information in the credit information block. Each node can only access the decrypted sensitive information with its corresponding private key. S6: Establish an access permission mechanism based on proof-of-work. Accessing nodes need to complete a lightweight proof-of-work with a preset difficulty level. Only after successful verification can they submit an access request. The system allocates the corresponding access scope according to the identity and permissions of the accessing nodes. At the same time, the blockchain's chain structure is used to realize the full-process traceability of credit information and to query the collection, processing, on-chain and access records of credit information in real time. S7: When abnormal computing power, forged proof of work, unauthorized access, or signs of credit information tampering are detected, an abnormality warning is triggered, and the transaction and access permissions of the relevant nodes are suspended. At the same time, backup nodes are started to supplement computing power.

2. The method for protecting credit information security based on blockchain workload mechanism according to claim 1, characterized in that: The proof-of-work algorithm uses the SHA-256 hash algorithm. The difficulty threshold for work calculation is dynamically adjusted according to the real-time computing power of the consortium blockchain network, and the adjustment period is every 2016 blocks.

3. The method for protecting credit information security based on the blockchain workload mechanism according to claim 1, characterized in that: The desensitization process involves partially replacing and hiding characters in the credit subject's ID card number, mobile phone number, and bank card number, and blurring the credit subject's address and workplace. The integrity check verifies whether the original credit information contains required fields and whether the field format conforms to preset standards. Missing or abnormal fields need to be returned to the credit institution node for supplementation and improvement before reprocessing.

4. The method for protecting credit information security based on the blockchain workload mechanism according to claim 1, characterized in that: The structure of the candidate transaction block includes a block header and a block body. The block header contains the hash value of the previous block, the timestamp of the current block, the workload difficulty value, a random number placeholder, and a credit information digest. The block contains standardized credit information, credit institution node signatures, and preprocessed logs. The proof-of-work task includes candidate transaction block summaries, difficulty thresholds, and calculation rules.

5. The method for protecting credit information security based on blockchain workload mechanism according to claim 1, characterized in that: The workload calculation involves the verification node obtaining candidate transaction block digest information, initializing a random number, and performing a SHA-256 double hash calculation on the combination of the digest information and the random number. If the first N bits of the calculation result are 0, where N is the number of bits corresponding to the difficulty threshold, then the proof of work is completed; otherwise, the random number is iteratively updated and the hash calculation is repeated until the condition is met. The preset ratio for consensus verification is more than 2 / 3 of the total number of nodes in the network.

6. The method for protecting credit information security based on blockchain workload mechanism according to claim 1, characterized in that: The asymmetric encryption algorithm uses the RSA algorithm. Credit institution nodes hold private keys and are responsible for encrypting and decrypting sensitive credit information. Regulatory nodes and credit reporting nodes hold corresponding public keys and can only access encrypted credit information or non-sensitive information that has been decrypted after authorization. The blockchain ledger uses distributed storage, with each node storing a complete copy of the ledger.

7. The method for protecting credit information security based on blockchain workload mechanism according to claim 1, characterized in that: The difficulty threshold for the lightweight workload proof is 1 / 10 of the difficulty threshold for the normal workload proof; The access permissions are divided into three levels: Level 1 permissions allow access to credit information summaries, Level 2 permissions allow access to non-sensitive credit information, and Level 3 permissions allow access to complete sensitive credit information. The permission levels are jointly reviewed and assigned by the credit institution node and the regulatory node.

8. The method for protecting credit information security based on blockchain workload mechanism according to claim 1, characterized in that: The anomaly monitoring indicators include a single node's computing power accounting for more than 50% of the total network computing power, the hash value of the proof-of-work result not meeting the difficulty threshold, the access request not completing the lightweight proof-of-work, and the block hash value not matching the previous block hash value. After an anomaly is handled, the anomaly information and handling results are packaged into a new transaction block, and stored on the blockchain after proof-of-work is completed.

9. The method for protecting credit information security based on the blockchain workload mechanism according to any one of claims 1-8, characterized in that: The consortium blockchain network also includes backup nodes, which synchronize blockchain ledger data in real time. When verification nodes or credit institution nodes fail, backup nodes automatically start and take over the corresponding workload calculation, information verification and access response tasks.

10. The method for protecting credit information security based on the blockchain workload mechanism according to any one of claims 1-8, characterized in that: The credit information includes personal credit information and corporate credit information. For corporate credit information, the collection and verification of corporate operating conditions and asset and liability status are increased, and the workload calculation difficulty threshold for corporate credit information is higher than that for personal credit information.

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