Identity certificate implementation method and system based on block chain, and medium
By modeling verifiable credentials/verifiable representations as Soul-Bound Tokens (SBTs), identity credentials are managed on the blockchain, solving the problems of lack of automated identity verification and privacy protection in existing technologies, and realizing automated management of identity credentials and rich business applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI PUJIANG DIGITAL TECHNOLOGY CO LTD
- Filing Date
- 2024-10-15
- Publication Date
- 2026-04-17
AI Technical Summary
In existing technologies, the verifiable credentials/verifiable representations of distributed digital identities are usually managed by the holders themselves, lacking automated identity verification capabilities and failing to realize rich business scenarios, such as community airdrop rewards, while protecting user privacy.
Verifiable credentials/verifiable representations are modeled as Soul-Bound Tokens (SBTs) and managed on the blockchain. The assetization of identity credentials is realized through smart contracts, including issuance, receipt confirmation, destruction, and query, ensuring user privacy protection.
It achieves automated identity verification and rich business scenarios, such as community airdrop rewards, while protecting user privacy, thus improving the convenience and security of identity credential management.
Smart Images
Figure CN121887398A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of blockchain technology, and in particular to a method, system and medium for implementing identity credentials based on blockchain. Background Technology
[0002] Everyone has different identities; for example, a university student, an employee of a company or organization, a member of a social welfare or interest group, and a resident of a community. When participating in social activities, it is usually necessary to verify whether the participant has the corresponding identity.
[0003] Distributed Digital Identity (DID) provides a blockchain-based technology for verifying identity using Verifiable Credentials (VCs) / Verifiable Expressions (VPs). Each DID identity stores a DID document on the blockchain, and its corresponding DID document can be retrieved based on the DID identifier. A DID document is JSON data describing identity information, including the public key information of that DID identity. A VC is descriptive credential data where one DID endorses certain identity attributes of another DID. The issuer of the VC attaches their DID's digital signature to the VC, ensuring that the VC's content can be verified and is tamper-proof. A VP is a selective disclosure of the VC content, revealing only some attributes or a range of attributes. In current implementations, distributed digital identity VCs / VPs are typically managed by their holders, who must actively provide them for authentication. By retrieving the public key information of the DID document on the blockchain, the authenticity of the VC / VP signature can be verified.
[0004] Soulbound Tokens (SBTs) are non-fungible digital tokens based on blockchain technology. SBTs represent certain attributes of an identity, such as credentials or affiliations. Compared to common blockchain-based digital assets, such as NFTs, SBTs are primarily characterized by being tied to their respective accounts and non-transferable. An account can own multiple Soulbound Tokens representing different attributes, but a single Soulbound Token can only belong to one account.
[0005] Each digital identity's multiple identity attributes are essentially its identity assets. Therefore, programmable SBTs can be used to implement functions such as identity credential management, display, and verification, thereby improving the convenience of identity credential management and use, and enriching the application scenarios of digital identities.
[0006] In existing DID technologies, VC / VP credentials are typically stored off-blocks by their holders. When authentication is required, the VC / VP holder must manually provide their VC / VP to the authentication party. Currently, no technology can manage VC / VP identity credentials on the blockchain while protecting user privacy, providing automated authentication functions, and offering richer application scenarios based on identity-related businesses.
[0007] Specifically, current technology lacks a solution to realize VC / VP as digital assets and model them as SBTs. Furthermore, since VC / VP does not exist on the blockchain, it's impossible to further implement richer business scenarios based on their identity attributes. For example, if a community wants to airdrop rewards to its members, and the VC / VP is stored off-chain, it's impossible to identify who holds the VC / VP associated with that community member, thus hindering the automated completion of the airdrop reward operation.
[0008] If the full information of VC / VP is directly modeled as SBT, there is a risk of privacy leakage. Summary of the Invention
[0009] The purpose of this invention is to provide a blockchain-based method, system, and medium for implementing identity credentials, which assetizes VC / VP and models it as SBT, and sets up VC / VP as SBT on the blockchain. This allows VC / VP to be managed and automatically authenticated on the blockchain while ensuring user privacy, providing convenience for distributed digital identity and realizing functions such as identity credential management, display, and proof.
[0010] The objective of this invention can be achieved through the following technical solutions:
[0011] A blockchain-based method for implementing identity credentials involves modeling verifiable credentials (VC) / verifiable representations (VP) as soul-bound tokens to assetize identity credential information. The method then manages user identity credentials on the blockchain. The assetization process includes the following steps:
[0012] Confirm the recipient of the soul-binding token, wherein the recipient of the soul-binding token is a distributed digital identity object corresponding to different entities based on their different identities;
[0013] Generate the token metadata of the soul-bound token and store it in a distributed manner. The token metadata includes the identity credential information represented by the soul-bound token, presented in an encrypted manner, and the digital signature of the soul-bound token issuer and the digital signature of the soul-bound token recipient.
[0014] The issuer of the soul-bound token generates the soul-bound token and saves it to the blockchain;
[0015] The issuer of the Soulbound Token issues Soulbound Tokens to the recipient of the Soulbound Token.
[0016] The recipient of the Soul-Bound Token confirms whether to accept the Soul-Bound Token. If the recipient confirms acceptance, the recipient sends feedback information to the issuer of the Soul-Bound Token and receives the Soul-Bound Token, thus becoming the Soul-Bound Token holder. The Soul-Bound Token holder owns one or more Soul-Bound Tokens as their identity assets.
[0017] The information contained in the soul-bound token includes: unique token identifier, token type, token issuer, token holder, token issuance time, token validity period, and token metadata URI, wherein the token metadata URI points to the corresponding token metadata stored in the distributed data storage and sharing module.
[0018] The identity credential information includes the issuer of the identity credential, the issuance time, the content format, and the specific content of the identity credential.
[0019] The issuance and receipt of Soulbound Tokens is a two-way confirmation process. The issuer of the Soulbound Token verifies the identity of the recipient and generates the corresponding Soulbound Token. If the recipient confirms receipt of the Soulbound Token, the recipient calls the token receipt confirmation method based on the smart contract. The recipient uses their private key of their distributed digital identity to sign the Soulbound Token issued to them by the issuer and attaches the signature to the token's metadata, indicating that the recipient agrees to receive the Soulbound Token. Subsequently, the smart contract automatically changes the holder of the Soulbound Token to the recipient, and the Soulbound Token belongs to the recipient, becoming their identity asset.
[0020] The issuer's digital signature is a string of data signed with the issuer's private key using the Soul-Bound Token, used to ensure the immutability and verification of the identity credential data; the recipient's digital signature is a string of data encrypted with the recipient's private key using the Soul-Bound Token, and this data is written after the recipient confirms receipt.
[0021] The method also includes a process for destroying soul-bound tokens, which includes the following steps:
[0022] The token issuer invokes a token destruction method based on a smart contract. The token destruction method verifies whether the caller is the issuer of the soul-bound token. If not, the call fails. If so, the holder of the token is changed to a pre-set distributed digital identity account address used to store the destroyed soul-bound token, thereby destroying the soul-bound token and removing it from the holder's identity assets. The soul-bound token cannot be used or transferred again.
[0023] The method also includes a query process for soul-bound tokens, which includes the following steps:
[0024] Soul-bound token queryers can retrieve all the soul-bound tokens held by a user on the blockchain by calling a query method based on a smart contract and using the user's distributed digital identity.
[0025] Soul-bound token queryers can retrieve the corresponding soul-bound token and obtain its detailed information on the blockchain using the token's unique identifier.
[0026] The method also includes a verification process for soul-bound tokens. Soul-bound token verifiers obtain the identity credential information of soul-bound token holders by querying and verifying their soul-bound tokens on the blockchain. This verification process includes the following steps:
[0027] The Soul-Bound Token Verifier calls a verification method based on a smart contract. The verification method automatically calls a query method based on a smart contract to query the Soul-Bound Tokens held by the user, automatically filters the type of the target Soul-Bound Token, obtains the token metadata URI of the target Soul-Bound Token, queries the encrypted data of the identity credential information in the token metadata through the token metadata URI, and decrypts the identity credential information through cryptographic technology.
[0028] By using the distributed digital identity identifiers of the token issuer and holder bound by the soul, the corresponding distributed digital identity information document is retrieved from the blockchain. The public key of the token issuer and holder is obtained from the document, and the identity credential information is verified using the public key to confirm that the identity credential information has not been modified and has been endorsed by the token issuer and confirmed by the token holder, thus completing the verification of the identity credential information.
[0029] A blockchain-based identity credential implementation system, used to implement the method described above, includes: a soul-bound token lifecycle management module, a soul-bound token identity data generation and verification module, a distributed data storage and sharing module, and a blockchain module, wherein...
[0030] The Soul-Bound Token Lifecycle Management Module provides full lifecycle management functions for Soul-Bound Tokens, including the issuance, receipt confirmation, destruction, and query of Soul-Bound Tokens. The Soul-Bound Token is issued by the Soul-Bound Token issuer to the Soul-Bound Token recipient. The Soul-Bound Token recipient is an entity corresponding to different distributed digital identity objects based on its identity. When the Soul-Bound Token recipient confirms receipt and receives the Soul-Bound Token, it becomes the Soul-Bound Token holder. The Soul-Bound Token holder owns one or more Soul-Bound Tokens.
[0031] The Soul-Bound Token Identity Data Generation and Verification Module is used to provide token metadata generation and verification functions. Soul-Bound Token Verifiers obtain the identity credential information by querying and verifying the Soul-Bound Token holder's Soul-Bound Token on the blockchain. The token metadata includes the identity credential information represented by the Soul-Bound Token presented in an encrypted manner, the digital signature of the Soul-Bound Token issuer, and the digital signature of the Soul-Bound Token recipient.
[0032] The distributed data storage and sharing module is used to store the token metadata generated by the soul-binding token identity data generation and verification module after being encrypted using cryptographic algorithms.
[0033] The blockchain module is used to store soul-bound tokens.
[0034] A storage medium having a program stored thereon, which, when executed, implements the method described above.
[0035] Compared with the prior art, the present invention has the following beneficial effects:
[0036] (1) This invention models the VC / VP of DID technology as SBT, and assetizes the identity credential information, so that the user's identity credential can be managed on the blockchain while protecting user privacy, which facilitates the automatic verification of VC / VP without the need for VC / VP holders to provide it manually.
[0037] (2) By storing VC / VP assets on the blockchain, this invention enables richer application scenarios of identity on the blockchain. Attached Figure Description
[0038] Figure 1 This is a schematic diagram of the system structure of the present invention.
[0039] Figure 2 This is a workflow for soul-binding tokens in one embodiment. Detailed Implementation
[0040] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.
[0041] Example 1
[0042] This embodiment provides a blockchain-based identity credential implementation system, such as... Figure 1 As shown, the system includes: a soul-bound token lifecycle management module, a soul-bound token identity data generation and verification module, a distributed data storage and sharing module, and a blockchain module.
[0043] (1) Soul-bound Token Lifecycle Management Module: This module provides full lifecycle management functions for soul-bound tokens, including issuance, receipt confirmation, destruction, and querying. In one embodiment, this module includes a soul-bound token issuance submodule, a soul-bound token receipt confirmation submodule, a soul-bound token destruction submodule, and a soul-bound token query submodule.
[0044] (11) Soul-bound token issuance submodule, used by the token issuer to issue corresponding soul-bound tokens to users.
[0045] Any institution, organization, or individual with a digital identity can issue Soul-Bound Tokens to others. Specifically, the token issuer calls the Soul-Bound Token Minting method `__mint` in the smart contract to issue Soul-Bound Tokens to others, either once or in batches. The information contained in a Soul-Bound Token includes: a unique token identifier, token type, token issuer, token holder, token issuance time, token validity period, and token metadata URI. The token metadata URI points to the corresponding token metadata stored in the distributed data storage and sharing module, which details the identity information represented by the Soul-Bound Token. Since only the URL of the token metadata is publicly displayed on the blockchain, and the original detailed information of the token metadata is not shown on the blockchain, the identity information of its holder will not be leaked. Furthermore, the original information of the token metadata can be presented in an encrypted manner to avoid leaking user privacy. The original information of the token metadata is generated by the token metadata generation submodule of the Soul-Bound Token Identity Data Generation and Verification module. The SBTs generated through the Soul Binding Token Issuance Submodule will be stored on the blockchain. The SBT can be retrieved on the blockchain and its detailed information can be obtained through its unique token identifier.
[0046] (12) The Soul-Bound Token Receipt Confirmation Submodule is used for the token recipient to confirm receipt of the SBT issued to them by the token issuer. The issuance and receipt of the Soul-Bound Token is a two-way confirmation process. If the recipient confirms receipt, they will call the `__confirm` method of the smart contract in this submodule. The recipient will use their DID identity's private key to sign the SBT issued to them. This signature will be attached to the token metadata, indicating that the recipient agrees to receive the SBT. Subsequently, the smart contract automatically changes the SBT holder to the recipient, indicating that the final holder of the SBT is the recipient. The token will then belong to the recipient, becoming their identity asset.
[0047] The recipient of a Soul-Bound Token is an entity with different distributed digital identity objects corresponding to its different identities. When the recipient of a Soul-Bound Token confirms receipt and receives the Soul-Bound Token, it becomes the Soul-Bound Token holder. The Soul-Bound Token holder can own one or more Soul-Bound Tokens.
[0048] (13) Soul-bound Token Query Submodule, used to query the soul-bound tokens held by a user. The querying party can retrieve all the soul-bound tokens held by the user on the blockchain by calling the query method __balanceOf of the smart contract of the submodule, based on the user's DID identifier.
[0049] (14) Soul-Bound Token Destruction Module: This module is used by the token issuer to revoke the issued soul-bound tokens. The token issuer calls the smart contract method `__burn` of this submodule to destroy the soul-bound token, which will be removed from the holder's identity assets. Specifically, the `__burn` method verifies whether the caller is the token issuer; if not, the call fails. If so, the call succeeds, and the `__burn` method changes the token holder to a pre-set DID identity account address used to store the destroyed SBT. The original SBT holder no longer owns the SBT, and the SBT will be removed from the original holder's asset list. Furthermore, the SBT cannot be used or transferred again.
[0050] (2) Soul-binding token identity data generation and verification module: used to provide token metadata generation and verification functions, including a token metadata generation submodule and a token metadata verification submodule.
[0051] (21) Token Metadata Generation Submodule: This submodule generates token metadata, which includes the identity credential information represented by the Soul-Bound Token presented in encrypted form, the digital signature of the Soul-Bound Token issuer, and the digital signature of the Soul-Bound Token recipient. The issuer's digital signature is a string of data signed with the issuer's private key, used to ensure the identity credential data is tamper-proof and verifiable. The recipient's digital signature is a string of data encrypted with their private key, written after the recipient confirms receipt. This token metadata can be encrypted using cryptographic algorithms such as proxy re-encryption and then stored in the distributed data storage and sharing module.
[0052] The identity credential information includes the issuer of the identity credential, the date of issuance, the content format, and the specific content of the identity credential.
[0053] (22) Token metadata verification submodule: Soul-bound token verifiers can obtain the identity credential information by querying the soul-bound token of the soul-bound token holder on the blockchain and verifying it.
[0054] The Soul-Bound Token Verifier calls the smart contract verification method `__verify` of the submodule. The `__verify` method automatically calls the `__balanceOf` method of the Soul-Bound Token Query submodule to retrieve the SBT held by the user. The Token Metadata Verification submodule automatically filters the target token type, obtains the target token's metadata URI, and queries the encrypted data of the identity details in the distributed data storage and sharing module using the URI. It then decrypts the identity data using cryptographic techniques such as proxy re-encryption. Subsequently, the Token Metadata Verification submodule retrieves the corresponding DID document from the blockchain using the token issuer's and holder's DID identifiers. It obtains the public keys of the token issuer and holder from the DID document, uses the public keys to verify the identity data, confirms that the identity data has not been modified, and confirms that the identity information has been endorsed by the token issuer and confirmed by the token holder, thus completing the identity authentication.
[0055] (3) Distributed data storage and sharing module: used to store the token metadata generated by the soul-binding token identity data generation and verification module after being encrypted by cryptographic algorithms.
[0056] (4) Blockchain module: used to store soul-bound tokens.
[0057] Example 2
[0058] This embodiment provides a blockchain-based method for implementing identity credentials. This method models verifiable credentials (VC) / verifiable representations (VP) as soul-bound tokens, thus assetizing identity credential information. The method also enables on-chain management of user identity credentials within the blockchain. Figure 2 As shown, the method includes the assetization process of identity credentials, the destruction process of soul-bound tokens, the query process of soul-bound tokens, and the verification process of soul-bound tokens.
[0059] In this embodiment, the assetization process of soul-bound tokens includes the following steps:
[0060] S11, confirm the recipient of the soul-bound token;
[0061] S12, Generate the token metadata of the soul-bound token and store it in a distributed manner. The token metadata includes the identity credential information represented by the soul-bound token presented in an encrypted manner, the digital signature of the soul-bound token issuer, and the digital signature of the soul-bound token recipient.
[0062] S13, the soul-bound token issuer calls the soul-bound token minting method __mint of the smart contract to generate soul-bound tokens and save them to the blockchain;
[0063] S14, The issuer of the soul-bound token issues a soul-bound token to the recipient of the soul-bound token.
[0064] S15, the recipient of the soul-bound token confirms whether to receive the soul-bound token. If the recipient confirms the receipt, the recipient sends feedback information to the issuer of the soul-bound token and receives the soul-bound token, becoming the holder of the soul-bound token. The holder of the soul-bound token owns one or more soul-bound tokens as their identity assets.
[0065] The issuance and receipt of Soulbound Tokens is a two-way confirmation process. The issuer of the Soulbound Token verifies the identity of the recipient and generates the corresponding Soulbound Token. If the recipient confirms receipt of the Soulbound Token, the recipient calls the __confirm method of the smart contract. The recipient uses their private key of their distributed digital identity to sign the Soulbound Token issued to them by the issuer and attaches the signature to the token's metadata, indicating that the recipient agrees to receive the Soulbound Token. Subsequently, the smart contract automatically changes the holder of the Soulbound Token to the recipient, and the Soulbound Token belongs to the recipient, becoming their identity asset.
[0066] The destruction process of soul-bound tokens includes the following steps:
[0067] S21, the token issuer calls the token destruction method __burn based on the smart contract;
[0068] S22, the token destruction method verifies whether the caller is the issuer of the soul-bound token. If not, the call fails. If so, the holder of the token is changed to a pre-set distributed digital identity account address used to store the destroyed soul-bound token, thereby destroying the soul-bound token and removing it from the holder's identity assets. The soul-bound token cannot be used or transferred again.
[0069] The process of querying a soul-bound token includes the following steps:
[0070] S31, the soul-bound token queryer can retrieve all the soul-bound tokens held by the user on the blockchain by calling the query method __balanceOf based on the smart contract and using the user's distributed digital identity.
[0071] S32, Soul-bound token queryers can retrieve the corresponding Soul-bound token and obtain its detailed information on the blockchain through the token's unique identifier.
[0072] The verification process for Soulbound Tokens involves the Soulbound Token verifier querying and verifying the Soulbound Token holder's Soulbound Token on the blockchain to obtain their identity credential information. This verification process includes the following steps:
[0073] S41, the soul-bound token verifier calls the smart contract-based verification method __verify. The verification method automatically calls the smart contract-based query method to query the soul-bound tokens held by the user, automatically filters the type of the target soul-bound token, obtains the token metadata URI of the target soul-bound token, queries the encrypted data of the identity credential information in the token metadata through the token metadata URI, and decrypts the identity credential information through cryptographic technology.
[0074] S42 retrieves the corresponding distributed digital identity information document from the blockchain by using the distributed digital identity identifier of the token issuer and holder bound by the soul. It obtains the public key of the token issuer and holder from the document, uses the public key to verify the identity credential information, confirms that the identity credential information has not been modified, and confirms that the identity credential information has been endorsed by the token issuer and confirmed by the token holder, thus completing the verification of the identity credential information.
[0075] Example 3
[0076] This embodiment provides an application scenario description of the blockchain-based identity credential implementation system described in Embodiment 1.
[0077] Any institution, organization, or individual with a distributed digital identity can use this system to effectively manage social identity and attributes, including age, income, and credit, on the blockchain while protecting user identity privacy. This will improve the convenience of managing and using identity credentials and enrich the application scenarios of digital identity.
[0078] For example, a university possesses a distributed digital identity DID_A, and a current student at that university possesses a distributed digital identity DID_B. The university calls the Soul-Bound Token Issuance Submodule to issue a Soul-Bound Token SBT_B to the student. This Soul-Bound Token contains the following information: unique token identifier, token type, token issuer, token owner, token issuance time, token validity period, and token metadata URI. The token metadata URI is a JSON data point to a verifiable credential representing the student's identity, DID_B. This data includes: token metadata (VC issuer, issuance time, content format, on-campus declaration content (student's name, student ID, department, enrollment time, student status, etc.), the issuer's digital signature, and the recipient's digital signature. This data is generated by the token metadata generation submodule and stored in the distributed data storage and sharing module after encryption for easy subsequent retrieval.
[0079] The university student DID_B invokes the Soul-Binding Token Receiving and Confirmation Submodule to attach his / her private key signature to the Soul-Binding Token SBT_B. This SBT_B will then be transferred to DID_B's account, becoming an identity-related asset within DID_B's account.
[0080] When student DID_B uses their student identity to purchase a student ticket, the ticketing platform calls the Soul-Binding Token Query Submodule to query the blockchain for the identity asset SBT_B of type "student" owned by DID_B. The Token Metadata Verification Submodule retrieves the identity credential information carried by the token metadata corresponding to the token metadata URI of SBT_B, verifies the authenticity of SBT_B through signature verification, and determines that student DID_B has the right to purchase a student ticket after verification. During the authorization verification process, the student purchasing the ticket does not need to perform any operations, including actively providing verifiable credentials for their distributed digital identity, and the verifier only needs to call an interface to verify the ticket purchaser's identity, improving the convenience of identity credential use; at the same time, since the data stored on the blockchain is encrypted, the user's privacy information is also protected.
[0081] When the student graduates from the school, the university's DID_A will call the Soul Bound Token Destruction Submodule to destroy the SBT_B held by DID_B, which represents the student's identity. After destruction, DID_B will no longer hold SBT_B and will not be able to use the identity information represented by SBT_B to participate in related matters.
[0082] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0083] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.
Claims
1. A method for implementing identity credentials based on blockchain, characterized in that, This method models verifiable credentials (VC) / verifiable representations (VP) as soul-bound tokens, thereby assetizing identity credential information. It then manages user identity credentials on the blockchain. The method includes an assetization process for identity credentials, comprising the following steps: Confirm the recipient of the soul-binding token, wherein the recipient of the soul-binding token is a distributed digital identity object corresponding to different entities based on their different identities; Generate the token metadata of the soul-bound token and store it in a distributed manner. The token metadata includes the identity credential information represented by the soul-bound token, presented in an encrypted manner, and the digital signature of the soul-bound token issuer and the digital signature of the soul-bound token recipient. The issuer of the soul-bound token generates the soul-bound token and saves it to the blockchain; The issuer of the Soulbound Token issues Soulbound Tokens to the recipient of the Soulbound Token. The recipient of the Soul-Bound Token confirms whether to accept the Soul-Bound Token. If the recipient confirms acceptance, the recipient sends feedback information to the issuer of the Soul-Bound Token and receives the Soul-Bound Token, thus becoming the Soul-Bound Token holder. The Soul-Bound Token holder owns one or more Soul-Bound Tokens as their identity assets.
2. The method for implementing identity credentials based on blockchain according to claim 1, characterized in that, The information contained in the soul-bound token includes: unique token identifier, token type, token issuer, token holder, token issuance time, token validity period, and token metadata URI, wherein the token metadata URI points to the corresponding token metadata stored in the distributed data storage and sharing module.
3. The method for implementing identity credentials based on blockchain according to claim 1, characterized in that, The identity credential information includes the issuer of the identity credential, the issuance time, the content format, and the specific content of the identity credential.
4. The method for implementing identity credentials based on blockchain according to claim 1, characterized in that, The issuance and receipt of Soulbound Tokens is a two-way confirmation process. The issuer of the Soulbound Token verifies the identity of the recipient and generates the corresponding Soulbound Token. If the recipient confirms receipt of the Soulbound Token, the recipient calls the token receipt confirmation method based on the smart contract. The recipient uses their private key of their distributed digital identity to sign the Soulbound Token issued to them by the issuer and attaches the signature to the token's metadata, indicating that the recipient agrees to receive the Soulbound Token. Subsequently, the smart contract automatically changes the holder of the Soulbound Token to the recipient, and the Soulbound Token belongs to the recipient, becoming their identity asset.
5. The method for implementing identity credentials based on blockchain according to claim 1, characterized in that, The issuer's digital signature is a string of data signed with the issuer's private key using the Soul-Bound Token, used to ensure the immutability and verification of the identity credential data; the recipient's digital signature is a string of data encrypted with the recipient's private key using the Soul-Bound Token, and this data is written after the recipient confirms receipt.
6. The method for implementing identity credentials based on blockchain according to claim 1, characterized in that, The method also includes a process for destroying soul-bound tokens, which includes the following steps: The token issuer invokes a token destruction method based on a smart contract. The token destruction method verifies whether the caller is the issuer of the soul-bound token. If not, the call fails. If so, the holder of the token is changed to a pre-set distributed digital identity account address used to store the destroyed soul-bound token, thereby destroying the soul-bound token and removing it from the holder's identity assets. The soul-bound token cannot be used or transferred again.
7. A method for implementing identity credentials based on blockchain according to claim 2, characterized in that, The method also includes a query process for soul-bound tokens, which includes the following steps: Soul-bound token queryers can retrieve all the soul-bound tokens held by a user on the blockchain by calling a query method based on a smart contract and using the user's distributed digital identity. Soul-bound token queryers can retrieve the corresponding soul-bound token and obtain its detailed information on the blockchain using the token's unique identifier.
8. A method for implementing identity credentials based on blockchain according to claim 7, characterized in that, The method also includes a verification process for soul-bound tokens. Soul-bound token verifiers obtain the identity credential information of soul-bound token holders by querying and verifying their soul-bound tokens on the blockchain. This verification process includes the following steps: The Soul-Bound Token Verifier calls a verification method based on a smart contract. The verification method automatically calls a query method based on a smart contract to query the Soul-Bound Tokens held by the user, automatically filters the type of the target Soul-Bound Token, obtains the token metadata URI of the target Soul-Bound Token, queries the encrypted data of the identity credential information in the token metadata through the token metadata URI, and decrypts the identity credential information through cryptographic technology. By using the distributed digital identity identifiers of the token issuer and holder bound by the soul, the corresponding distributed digital identity information document is retrieved from the blockchain. The public key of the token issuer and holder is obtained from the document, and the identity credential information is verified using the public key to confirm that the identity credential information has not been modified and has been endorsed by the token issuer and confirmed by the token holder, thus completing the verification of the identity credential information.
9. A blockchain-based identity credential implementation system, characterized in that, To implement the method as described in any one of claims 1-8, the system comprises: a soul-bound token lifecycle management module, a soul-bound token identity data generation and verification module, a distributed data storage and sharing module, and a blockchain module, wherein... The Soul-Bound Token Lifecycle Management Module provides full lifecycle management functions for Soul-Bound Tokens, including the issuance, receipt confirmation, destruction, and query of Soul-Bound Tokens. The Soul-Bound Token is issued by the Soul-Bound Token issuer to the Soul-Bound Token recipient. The Soul-Bound Token recipient is an entity corresponding to different distributed digital identity objects based on its identity. When the Soul-Bound Token recipient confirms receipt and receives the Soul-Bound Token, it becomes the Soul-Bound Token holder. The Soul-Bound Token holder owns one or more Soul-Bound Tokens. The Soul-Bound Token Identity Data Generation and Verification Module is used to provide token metadata generation and verification functions. Soul-Bound Token Verifiers obtain the identity credential information by querying and verifying the Soul-Bound Token holder's Soul-Bound Token on the blockchain. The token metadata includes the identity credential information represented by the Soul-Bound Token presented in an encrypted manner, the digital signature of the Soul-Bound Token issuer, and the digital signature of the Soul-Bound Token recipient. The distributed data storage and sharing module is used to store the token metadata generated by the soul-binding token identity data generation and verification module after being encrypted using cryptographic algorithms. The blockchain module is used to store soul-bound tokens.
10. A storage medium having a program stored thereon, characterized in that, When the program is executed, it implements the method as described in any one of claims 1-8.