Block chain-based trusted data circulation transaction platform implementation method and system

Abstract

The invention relates to the technical field of data transaction and block chains, in particular to a trusted data circulation transaction platform implementation method and system based on a block chain, and the method comprises the following steps: platform deployment and architecture construction, and block chain configuration. The method has the beneficial effects that through the generated distributed digital identity, it is ensured that the identity information of each transaction platform obtains a unique and non-tampering record on the block chain, and the security of data transaction is improved. And the data is encrypted by adopting an encryption technology, and only an authorized user can decrypt and check the data content, so that data leakage and unauthorized access are prevented.

Description

Technical Field

[0001] The present invention relates to the technical fields of data trading and blockchain, and specifically provides a method and system for implementing a trusted data circulation and trading platform based on blockchain. Background Art

[0002] With the advent of the big data era, the value of data has become increasingly prominent. However, there are many problems in the process of data circulation and trading, such as the difficulty in ensuring data authenticity, the easy infringement of data ownership, and the lack of transparency in the trading process.

[0003] Traditional data trading platforms are difficult to completely solve these problems, while blockchain technology has characteristics such as decentralization, immutability, and traceability, providing new ideas for building a trusted data circulation and trading platform. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for implementing a trusted data circulation and trading platform based on blockchain. By utilizing the characteristics of blockchain such as immutability, decentralization, and traceability, the present invention provides the capabilities of rights confirmation and evidence storage for the data trading platform, and solves the pain points of insufficient protection of data ownership and non-public and transparent trading processes in existing data circulation and trading platforms.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A method for implementing a trusted data circulation and trading platform based on blockchain, comprising the following steps:

[0006] Platform deployment and architecture construction: Select Linux as the server operating system, PostgreSQL as the database, Fabric as the blockchain platform, Vue as the front-end framework, and Golang as the back-end programming language to build a distributed trading platform; store information of other trading platforms in the database table, including the trading platform name, address, port number, and identifier, to enable access between trading platforms;

[0007] Blockchain configuration: Use the Fabric blockchain with the Raft consensus algorithm, and equip it with four smart contracts: a distributed digital identity contract, a deposit and evidence-taking contract, a data product rights confirmation contract, and a trading platform signature verification contract.

[0008] Preferably, the platform trading process includes steps of product listing and placing an order to purchase:

[0009] Product listing: The user adds new data sources. The data source types include files and data interfaces. The file-type data source includes file size, file name, file type, and file content. The data-interface-type data source includes interface description, address, and port number. The newly added data sources are aggregated into data resources, and only data sources of the same type are allowed to exist in the newly added data resources. A new data product is added. The data resources containing valuable data are encapsulated into data products in combination with business information, and the administrator formulates an access control policy for it. Use the private key of the local trading platform to sign the relevant information, package and send it to the blockchain network, and confirm the rights through a smart contract to generate a unique on-shelf data product identifier.

[0010] Placing an order to purchase: The user selects another trading platform on the local trading platform, views the listed data products, and places an order after entering the desired control policy and price information. The trading platform creates the same order locally on both sides. The provider views the order and conducts feedback negotiation. After modifying the feedback, the order status becomes "feedback given", and the user confirms the order. The provider delivers the order, packages the order information and the trading platform information of both sides and sends it to the blockchain platform for transaction deposit and obtains a transaction ID. After the provider delivers the order, the user can obtain the purchased data product on the local trading platform and perform operations such as downloading, calling, and viewing.

[0011] Preferably, the steps for generating and verifying the distributed digital identity and public-private key of the trading platform are as follows:

[0012] Generating public-private keys: When the trading platform is initialized, a pair of national cryptography SM2 public-private keys are generated. The private key is used for signing, and the public key is used for signature verification.

[0013] Obtaining the distributed digital identity identifier: Package the public key and the basic information of the trading platform and send it to the blockchain platform, and call the distributed digital identity smart contract to obtain the distributed digital identity identifier.

[0014] Identity verification: When requesting an external trading platform, use the private key to perform a random number challenge on the timestamp, that is, 〖Sign〗_SM2PriviteKey{Nonce(timestamp.Now)}. The other trading platform looks up the corresponding public key according to the distributed digital identity and uses the public-private key signature verification smart contract to verify the identity.

[0015] Preferably, the steps for data product rights confirmation are as follows: When publishing a product, sign the distributed digital identity identifier of the local trading platform and the product-related information with the private key, and send it to the blockchain platform together with the public key. The blockchain platform checks whether there is such a public key, uses the public key to verify the signature and decrypt the corresponding data. Based on the hash value of the above information, that is, Hash, obtain the data product identifier.

[0016] Preferably, the steps for order transaction deposit and evidence collection are as follows:

[0017] Transaction deposit and evidence: When the order status is delivered, request the deposit and evidence contract of the blockchain platform to conduct transaction deposit and evidence. Desensitize and store the distributed digital identities of both parties' trading platforms, order IDs, product identifiers, and other order information, generate and return a blockchain transaction ID, and the provider and user deposit this blockchain transaction ID into the database;

[0018] Evidence collection operation: When the provider or user conducts an evidence collection operation, send the distributed digital identity of the requester and the blockchain transaction ID encrypted with the private key in the order table to the deposit and evidence contract of the blockchain platform; inside the contract, query the public key of the corresponding trading platform according to the distributed digital identity, verify whether the decrypted plaintext is consistent with the information sent by the requester. If it is consistent, query the relevant information deposited previously and return it to the requester after processing.

[0019] A system for implementing a trusted data circulation and trading platform based on blockchain, including:

[0020] Platform architecture module: Build a distributed trading platform using Linux servers, PostgreSQL databases, Fabric blockchains, Vue front-end frameworks, and Golang back-end programming languages; store the names, addresses, port numbers, and identifiers of other trading platforms in the database table to support access between trading platforms;

[0021] Blockchain configuration module: Select a Fabric blockchain with the Raft consensus algorithm and equip it with four smart contracts: a distributed digital identity contract, a deposit and evidence contract, a data product rights confirmation contract, and a trading platform signature verification contract.

[0022] Preferably, it further includes a platform trading process module, and specifically:

[0023] Product shelving module: Support users to add data sources of file or data interface types. The file type data source includes file size, file name, file type, and file content. The data interface type data source includes interface description, address, and port number; aggregate the newly added data sources into data resources, and only allow data sources of the same type to exist in the data resources; support adding data products, encapsulate valuable data resources combined with business information into data products, and allow administrators to formulate access control policies; when shelving products, sign the relevant information with the private key of the local trading platform, package and send it to the blockchain network, and confirm the rights through smart contracts to generate a unique on-shelf data product identifier;

[0024] Product Order Sub-module: It supports the user to create a point-to-point order, which includes the information of both parties' trading platforms and the information of the data products on the shelf related to the order; the user can select other trading platforms on the local trading platform, view the data products that have been put on the shelf, and place an order after entering the expected control strategy and price information; the trading platform creates the same order on both parties' local sides, and the provider can view the order for feedback negotiation. After modifying the feedback, the order status becomes "Feedback Given", and the order cannot be modified after the user confirms it; when the provider delivers the order, the order information and the information of both parties' trading platforms are packaged and sent to the blockchain platform for transaction evidence storage to obtain a transaction ID; after the provider delivers the order, the user can obtain the purchased data products on the local trading platform and perform operations such as downloading, calling, and viewing.

[0025] Preferably, it further includes a distributed digital identity and public-private key module for the trading platform, and this module specifically includes:

[0026] Public-Private Key Generation Sub-module: When the trading platform is initialized, a pair of national cryptography SM2 public-private keys are generated. The private key is used for signing, and the public key is used for signature verification.

[0027] Distributed Digital Identity Acquisition Sub-module: The public key and the basic information of the trading platform are packaged and sent to the blockchain platform, and the distributed digital identity smart contract is called to obtain the distributed digital identity identifier.

[0028] Identity Verification Sub-module: When requesting an external trading platform, use the private key to perform a random number challenge on the timestamp, that is, 〖Sign〗_SM2PriviteKey{Nonce(timestamp.Now)}; the other party's trading platform looks up the corresponding public key according to the distributed digital identity and uses the public-private key signature verification smart contract to verify the identity.

[0029] Preferably, it further includes a data product right confirmation module, and this module specifically includes: When publishing a product, the distributed digital identity identifier of the local trading platform and the product-related information are signed with the private key and sent to the blockchain platform together with the public key; the blockchain platform checks whether there is such a public key, uses the public key for signature verification and decrypts the corresponding data; based on the hash value of the above information, that is, Hash, the data product identifier is obtained.

[0030] Preferably, it further includes an order transaction evidence storage and forensics module, and this module specifically includes:

[0031] Transaction Evidence Storage Sub-module: When the order status is "Delivered", request the evidence storage and forensics contract of the blockchain platform for transaction evidence storage. The distributed digital identities of both parties' trading platforms, the order ID, the product identifier, and other order information are stored in a desensitized manner, and a blockchain transaction ID is generated and returned. The provider and the user store this blockchain transaction ID in the database.

[0032] Forensics operation sub-module: When the provider or user performs a forensics operation, the distributed digital identity of the requester and the blockchain transaction ID encrypted with the private key in the order table are sent to the forensics and archiving contract on the blockchain platform. The contract queries the public key of the corresponding trading platform based on the distributed digital identity, verifies whether the decrypted plaintext is consistent with the information sent by the requester. If they are consistent, it queries the previously archived relevant information and returns it to the requester after processing.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] The method and system for implementing a trusted data circulation trading platform based on blockchain proposed by the present invention ensure that the identity information of each trading platform is uniquely and immutably recorded on the blockchain through the generated distributed digital identity, improving the security of data transactions. Encryption technology is used to encrypt data, and only authorized users can decrypt and view the data content, preventing data leakage and unauthorized access.

[0035] Using public-private key pairs and blockchain technology, it ensures clear ownership of data and prevents data from being illegally copied or tampered with. Each transaction is recorded on the blockchain, forming a complete data flow chain, facilitating the tracing of the source and usage of transactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] In order to clearly and completely describe the objectives, technical solutions of the present invention, and make the advantages more clearly understood, the following further details the embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are some but not all embodiments of the present invention, and are only used to explain the embodiments of the present invention, not to limit the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0038] Embodiment 1, please refer to Figure 1 , the present invention provides a technical solution: A method for implementing a trusted data circulation trading platform based on blockchain, including the following content:

[0039] 1. Trading platform and blockchain architecture

[0040] The present invention is a distributed trading platform for relevant enterprises such as data exchanges and needs to be deployed within each data exchange. Among them, Linux is selected for the server, PostgreSQL is selected for the database, Fabric is selected for the blockchain, Vue is used for the front end, and Golang is used for programming the back end.

[0041] In terms of internal architecture, the trading platforms need to access each other. Therefore, information about other trading platforms needs to be stored in the database table. In the present invention, the trading platform name, address, port number, and identifier are stored in the database table. With the addresses and port numbers of other trading platforms, the local trading platform can access the products inside other trading platforms through a unified interface standard for placing orders and viewing. When releasing a product, relevant information needs to be transmitted to the blockchain, and the smart contract automatically running in the blockchain will confirm the rights of the data product to be released, ensuring that the ownership of the product belongs to a specific trading platform. When an order is generated, the blockchain will deposit and prove the transaction information and write the transaction information into the blockchain.

[0042] The Fabric blockchain used in the present invention uses the Raft consensus algorithm and is equipped with four types of smart contracts: distributed digital identity contract, deposit and evidence contract, data product right confirmation contract, and trading platform signature verification contract.

[0043] 2. Platform trading process

[0044] The trading platform designed in the present invention serves both as a user and as a provider, that is, users can both release products and place orders for the products listed on other trading platforms.

[0045] When a user wants to list a product on the trading platform: First, a data source needs to be newly added. The data source has types such as files and data interfaces, indicating which specific data the product contains. Among them, the data source of the file type should include file size, file name, file type, and file content (base64 encoded) in addition to the basic information of the data source. The data source of the data interface type should additionally include interface description, address, and port number. Then, the newly added data sources need to be aggregated into data resources to facilitate the management of multiple data sources by the product, so that the product table only needs to store the primary key of the resource table to be associated with multiple data sources. Only data sources of the same type are allowed to exist in the newly added data resources according to the principle, which is convenient for the classified management of data products. After adding the data resources, a data product needs to be newly added. This process can be understood as a data processing process, in which the data resources containing valuable data are combined with some business information to be encapsulated into a data product. When adding a data product, the administrator can formulate a guiding strategy for it, that is, an access control strategy, which indicates the usage restrictions for control operations such as downloading, viewing, and calling. The platform fee will also be carried out according to the number of times, capacity, or time of the control operations. Finally, the product needs to be published (listed) operation. After listing, the data product can be ordered and purchased by other trading platforms. When listing, the private key of the local trading platform needs to be used to sign some relevant information, and then it is packaged and sent to the blockchain network. The smart contract is used to confirm the publishing operation and generate a unique on-shelf data product identifier, which indicates the specific content of the data product and the owner of the data product. The specific details are described in Section 4.4.

[0046] When a user wants to place an order for a product on a trading platform: When placing an order for an on-shelf data product on another trading platform, a peer-to-peer order needs to be created. The order content includes information about both trading platforms and information related to the on-shelf data product being ordered. First, the user, i.e., the purchaser, needs to select a trading platform at the local trading platform, view the available on-shelf data products for ordering on that platform, and then place an order after entering the desired control strategy and price information. At this time, the trading platform will create an identical order locally on both sides. The provider can view the order in the local trading platform for feedback and negotiation. In this process, the provider can make multiple modification feedbacks based on the control strategy and price expected by the user. When the feedback is made, the status of the order will change to "feedback given". At this time, the user can confirm the order in the local trading platform. After confirmation, the order cannot be modified anymore. After the user confirms the order, the provider should deliver it. The delivery will package the order information and the information of both trading platforms and send them to the blockchain platform for transaction record keeping, and then obtain a transaction ID for subsequent evidence collection. After the provider delivers the order, the user can obtain the purchased data product in the local trading platform. This process will package the relevant data product information in the provider's trading platform and send it to the user's trading platform for storage in the database. The user can then perform operations such as downloading, invoking, and viewing.

[0047] 3. Distributed Digital Identity and Public-Private Key of the Trading Platform

[0048] The trading platform designed in the present invention is equipped with a distributed digital identity for identifying the trading platform and a pair of public-private keys for communication verification between trading platforms. First, when the trading platform is initialized, a pair of national cryptography SM2 public-private keys is generated. The private key is used for signing, and the public key is used for signature verification. By packaging the public key and the basic information of the trading platform and sending them to the blockchain platform to call the distributed digital identity smart contract, a distributed digital identity identifier will be obtained. When requesting an external trading platform, the private key needs to be used to make a random number challenge to the timestamp. That is, 〖Sign〗_SM2PriviteKey{Nonce(timestamp.Now)}

[0049] The other trading platform needs to find the corresponding public key according to the distributed digital identity of the trading platform, and then use the public-private key signature verification smart contract to verify the identity of the other trading platform.

[0050] 4. Data Product Right Confirmation

[0051] When releasing a product, the distributed digital identity of the local trading platform and product-related information need to be signed with a private key, and then sent to the blockchain platform together with the public key. The blockchain platform first checks if the public key exists, then uses the public key to verify the signature, and then decrypts the corresponding data. Then, based on the hash value of the above information, i.e., Hash(DID + ProductInfo), the data product identifier is obtained.

[0052] 5. Order Transaction Archiving

[0053] When the order status is delivered, it is necessary to request the archiving and evidence-taking contract of the blockchain platform for transaction archiving. The distributed digital identities of both trading platforms, order IDs, product identifiers, and other order information are stored in a desensitized manner, and then a blockchain transaction ID is generated and returned. The provider and user deposit this blockchain transaction ID into the database for evidence-taking purposes.

[0054] When the provider or user conducts an evidence-taking operation, the distributed digital identity of the requesting party and the blockchain transaction ID encrypted with the private key in the order table will be sent to the archiving and evidence-taking contract of the blockchain platform. Inside the contract, first, the public key of the corresponding trading platform is queried based on the distributed digital identity, and then it is verified whether the decrypted plaintext is consistent with the information sent by the requesting party. If they are consistent, the relevant information archived previously will be queried, processed, and returned to the requesting party for evidence-taking use.

[0055] Embodiment 2, based on Embodiment 1, proposes a system for implementing a blockchain-based trusted data circulation trading platform, including:

[0056] Platform Architecture Module: Build a distributed trading platform using Linux servers, PostgreSQL databases, Fabric blockchains, Vue front-end frameworks, and Golang back-end programming languages; store the names, addresses, port numbers, and identifiers of other trading platforms in database tables to support access between trading platforms;

[0057] Blockchain Configuration Module: Select a Fabric blockchain with the Raft consensus algorithm and equip it with four smart contracts: a distributed digital identity contract, an archiving and evidence-taking contract, a data product rights confirmation contract, and a trading platform signature verification contract.

[0058] It also includes a platform trading process module, which specifically includes: Product shelving module: It supports users to add data sources of file or data interface types. The data source of file type includes file size, file name, file type, and file content. The data source of data interface type includes interface description, address, and port number. It aggregates the newly added data sources into data resources, and only the same type of data source is allowed to exist in the data resources. It supports adding data products, encapsulating valuable data resources combined with business information into data products, and allows administrators to formulate access control policies. When shelving products, it signs relevant information with the private key of the local trading platform, packages and sends it to the blockchain network, and confirms the rights through a smart contract to generate a unique on-shelf data product identifier. Product ordering sub-module: It supports the user side to create a peer-to-peer order, and the order includes the information of both trading platforms and the relevant information of the on-shelf data product placed in the order. The user side can select other trading platforms on the local trading platform, view the on-shelved data products, and place an order after entering the expected control policy and price information. The trading platform creates the same order locally for both parties. The provider side can view the order for feedback negotiation. After modifying the feedback, the order status becomes "already feedback". After the user side confirms the order, the order cannot be modified. When the provider side delivers the order, it packages the order information and the information of both trading platforms and sends it to the blockchain platform for transaction deposit and obtains a transaction ID. After the provider side delivers the order, the user side can obtain the purchased data product on the local trading platform and perform operations such as downloading, calling, and viewing.

[0059] It also includes a trading platform distributed digital identity and public-private key module, which specifically includes: Public-private key generation sub-module: When the trading platform is initialized, a pair of national cryptography SM2 public-private keys is generated. The private key is used for signing, and the public key is used for signature verification. Distributed digital identity acquisition sub-module: It packages the public key and the basic information of the trading platform and sends it to the blockchain platform, calls the distributed digital identity smart contract, and obtains the distributed digital identity identifier. Identity verification sub-module: When requesting an external trading platform, it uses the private key to make a random number challenge to the timestamp, that is, 〖Sign〗_SM2PriviteKey{Nonce(timestamp.Now)}. The other trading platform looks up the corresponding public key according to the distributed digital identity and uses the public-private key signature verification smart contract to verify the identity.

[0060] It also includes a data product right confirmation module, which specifically includes: When publishing a product, it signs the distributed digital identity identifier of the local trading platform and the product-related information with the private key, and sends them to the blockchain platform together with the public key. The blockchain platform checks whether there is such a public key, uses the public key for signature verification and decrypts the corresponding data. Based on the hash value of the above information, that is, Hash, it obtains the data product identifier.

[0061] It also includes an order transaction deposit and evidence collection module, which specifically includes: a transaction deposit sub-module: when the order status is delivery, it requests the deposit and evidence collection contract of the blockchain platform to conduct transaction deposit, desensitizes and stores the distributed digital identities of both parties' trading platforms, order IDs, product identifiers, and other order information, generates and returns a blockchain transaction ID, and both the provider and the user deposit this blockchain transaction ID into the database; an evidence collection operation sub-module: when the provider or the user conducts an evidence collection operation, it sends the distributed digital identity of the requesting party and the blockchain transaction ID encrypted with the private key in the order table to the deposit and evidence collection contract of the blockchain platform; the contract queries the public key of the corresponding trading platform according to the distributed digital identity, verifies whether the decrypted plaintext is consistent with the information sent by the requesting party, and if it is consistent, it queries the relevant information deposited previously and returns it to the requesting party after processing.

[0062] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for implementing a trusted data circulation and trading platform based on blockchain, characterized in that: It includes the following steps: Platform deployment and architecture setup: Select Linux as the server operating system, PostgreSQL as the database, Fabric as the blockchain platform, Vue as the front-end framework, and Golang as the back-end programming language to build a distributed trading platform; store information of other trading platforms in the database table, including trading platform name, address, port number, and identifier, to enable access between trading platforms; Blockchain configuration: Use the Fabric blockchain with the Raft consensus algorithm, equipped with four smart contracts: distributed digital identity contract, deposit and evidence-taking contract, data product rights confirmation contract, and trading platform signature verification contract.

2. The implementation method of a blockchain-based trusted data circulation and trading platform according to claim 1, characterized in that: The platform trading process includes product listing and order placement steps: Product listing: Users add data sources, and the data source types include files and data interfaces. The file-type data source includes file size, file name, file type, and file content, and the data-interface-type data source includes interface description, address, and port number; collect the newly added data sources into data resources, and only data sources of the same type are allowed to exist in the newly added data resources; add a data product, encapsulate the data resources containing valuable data together with business information into a data product, and the administrator formulates an access control policy for it; use the private key of the local trading platform to sign the relevant information, pack and send it to the blockchain network, and generate a unique on-shelf data product identifier through smart contract rights confirmation; Order placement: The user selects another trading platform on the local trading platform, views the listed data products, and places an order after entering the expected control policy and price information; the trading platform creates the same order locally for both parties. The provider views the order and conducts feedback negotiation. After modifying the feedback, the order status becomes "feedback given", and the user confirms the order; the provider delivers the order, packs the order information and the trading platform information of both parties and sends it to the blockchain platform for transaction deposit and evidence-taking to obtain a transaction ID; after the provider delivers the order, the user obtains the purchased data product on the local trading platform and can perform download, call, and view operations.

3. The implementation method of a blockchain-based trusted data circulation and trading platform according to claim 2, characterized in that: The steps for generating and verifying the distributed digital identity and public-private keys of the trading platform are as follows: Generate public-private keys: When the trading platform is initialized, a pair of national cryptography SM2 public-private keys is generated. The private key is used for signing, and the public key is used for signature verification; Obtain the distributed digital identity identifier: Pack the public key and the basic information of the trading platform and send it to the blockchain platform, and call the distributed digital identity smart contract to obtain the distributed digital identity identifier; Identity verification: When requesting an external trading platform, use the private key to make a random number challenge to the timestamp, that is, 〖Sign〗_SM2PriviteKey{Nonce(timestamp.Now)}; the other trading platform looks up the corresponding public key according to the distributed digital identity and uses the public-private key signature verification smart contract to verify the identity.

4. A method for implementing a trusted data circulation and trading platform based on blockchain according to claim 3, characterized in that: The steps for the confirmation of the rights of data products are as follows: When releasing a product, use the private key to sign the distributed digital identity of the local trading platform and product-related information, and send them together with the public key to the blockchain platform; The blockchain platform checks whether there is such a public key, uses the public key to verify the signature and decrypt the corresponding data; Based on the hash value of the above information, that is, Hash, obtain the data product identifier.

5. The implementation method of a blockchain-based trusted data circulation and trading platform according to claim 4, characterized in that: The steps for order transaction evidence preservation and evidence collection are as follows: Transaction evidence preservation: When the order status is delivery, request the evidence preservation and collection contract of the blockchain platform to conduct transaction evidence preservation, desensitize and store the distributed digital identities of both trading platforms, order ID, product identifier, and other order information, generate and return a blockchain transaction ID, and the provider and user deposit this blockchain transaction ID into the database; Evidence collection operation: When the provider or user conducts an evidence collection operation, send the distributed digital identity of the requesting party and the blockchain transaction ID encrypted with the private key in the order table to the evidence preservation and collection contract of the blockchain platform; According to the distributed digital identity in the contract, query the public key of the corresponding trading platform, verify whether the decrypted plaintext is consistent with the information sent by the requesting party. If it is consistent, query the relevant information of the previous evidence preservation, and return it to the requesting party after processing.

6. A system for implementing the method of a blockchain-based trusted data circulation and trading platform according to claim 5, characterized in that: Including: Platform architecture module: Build a distributed trading platform using Linux servers, PostgreSQL databases, Fabric blockchains, Vue front-end frameworks, and Golang back-end programming languages; Store the names, addresses, port numbers, and identifiers of other trading platforms in the database table to support access between trading platforms; Blockchain configuration module: Select a Fabric blockchain with the Raft consensus algorithm and equip it with four smart contracts: a distributed digital identity contract, an evidence preservation and collection contract, a data product rights confirmation contract, and a trading platform signature verification contract.

7. A system according to claim 6, characterized in that: It also includes a platform trading process module, which specifically is: Product shelving sub-module: Support users to add data sources of file or data interface types. The file type data source includes file size, file name, file type, and file content. The data interface type data source includes interface description, address, and port number; Aggregate the newly added data sources into data resources, and only allow data sources of the same type to exist in the data resources; Support the addition of data products, encapsulate valuable data resources combined with business information into data products, and allow administrators to formulate access control policies; When shelving a product, use the private key of the local trading platform to sign the relevant information, package and send it to the blockchain network, and confirm the rights through a smart contract to generate a unique on-shelf data product identifier; Product ordering sub-module: Support the user to create a peer-to-peer order, and the order includes the information of both trading platforms and the information related to the on-shelf data product ordered. The user can select other trading platforms on the local trading platform, view the listed data products, place an order after entering the desired control strategy and price information; the trading platform creates the same order on both parties' local sides, the provider can view the order for feedback negotiation, and after modifying the feedback, the order status becomes "feedback given", and the order cannot be modified after the user confirms the order; when the provider delivers the order, the order information and the information of both parties' trading platforms are packaged and sent to the blockchain platform for transaction deposit and evidence collection, and a transaction ID is obtained; after the provider delivers the order, the user can obtain the purchased data product on the local trading platform and perform operations such as downloading, calling, and viewing.

8. A system according to claim 7, characterized in that: It also includes a distributed digital identity and public-private key module for the trading platform, which specifically includes: Public-private key generation sub-module: When the trading platform is initialized, a pair of national cryptographic SM2 public-private keys is generated. The private key is used for signing, and the public key is used for signature verification. Distributed digital identity acquisition sub-module: The public key and the basic information of the trading platform are packaged and sent to the blockchain platform, and the distributed digital identity smart contract is called to obtain the distributed digital identity identifier. Identity verification sub-module: When requesting an external trading platform, the private key is used to perform a random number challenge on the timestamp, that is, 〖Sign〗_SM2PriviteKey{Nonce(timestamp.Now)}; the other party's trading platform looks up the corresponding public key according to the distributed digital identity and uses the public-private key signature verification smart contract to verify the identity.

9. A system according to claim 8, characterized in that: It also includes a data product rights confirmation module, which specifically includes: When publishing a product, the distributed digital identity identifier of the local trading platform and the product-related information are signed with the private key and sent to the blockchain platform together with the public key; the blockchain platform checks whether there is such a public key, uses the public key for signature verification and decrypts the corresponding data; based on the hash value of the above information, that is, Hash, the data product identifier is obtained.

10. A system according to claim 9, characterized in that: It also includes an order transaction deposit and evidence collection module, which specifically includes: Transaction deposit sub-module: When the order status is "delivered", request the deposit and evidence collection contract of the blockchain platform for transaction deposit, desensitize and store the distributed digital identities of both parties' trading platforms, the order ID, the product identifier, and other order information, generate and return a blockchain transaction ID, and the provider and the user store this blockchain transaction ID in the database. Evidence collection operation sub-module: When the provider or the user performs an evidence collection operation, the distributed digital identity of the requesting party and the blockchain transaction ID encrypted with the private key in the order table are sent to the deposit and evidence collection contract of the blockchain platform. Inside the contract, the public key of the corresponding trading platform is queried according to the distributed digital identity, and it is verified whether the decrypted plaintext is consistent with the information sent by the requesting party. If it is consistent, the relevant information stored in the previous deposit is queried and processed and then returned to the requesting party.

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