KR-20260063047-A - Method for Linking Off-Chain Attributes with Verifiable Credentials on Blockchain

Abstract

The present invention aims to resolve the disconnect between existing identity verification systems and blockchain-based Self-Sovereign Identity (SSI) systems by linking attribute information verified in an off-chain environment to a blockchain-based Verifiable Credential (VC). Users can process attribute information issued by an off-chain verification agency through a blockchain smart contract and utilize the VC generated based on this for various services. The core of the present invention is to ensure the reliability of off-chain data through Decentralized Multi-Party Computation (DMPC) and to automate verification and authentication procedures in smart contracts (100). The attribute verification unit (120) processes externally verified information and generates a VC through the attribute certificate management unit (130), and stores it in a digital wallet associated with the user's DID. The response consensus unit (140) combines the verification results of multiple nodes to determine the integrity of the data, and the history recorded on the blockchain is managed transparently. Through this invention, users can reuse verified attribute information across various services without duplication, and prove that conditions are met without disclosing specific attribute values through zk-SNARKs-based zero-knowledge proofs. Additionally, rewards are automatically paid to users and verification bodies participating in the authentication process via smart contracts, and all reward records are recorded on the blockchain for transparent management. This invention ensures interoperability between off-chain and blockchain-based systems and provides efficient and reliable identity authentication services across various industrial sectors. Through this, it realizes privacy protection, data integrity, and authentication automation, creating a convenient authentication environment for both users and organizations.

Inventors

• 최종석

Assignees

• 주식회사 바이야드

Dates

Publication Date

20260507

Application Date

20241030

Claims (5)

1. A system for attribute verification between blockchain and off-chain attribute verification services, Composed of blockchain smart contracts, Web 2.0 attribute verification services, and attribute certificate-based services.
2. In Article 1, A structure for verifying attributes by calling an off-chain service from a blockchain smart contract.
3. In Paragraph 2, For off-chain attribute verification in blockchain smart contracts, A system in which multiple nodes agree on a response to an external call.
4. In Paragraph 2, A system that performs off-chain attribute verification using DMPC-based data as a seed.
5. In Article 1, A system that enables off-chain services to utilize verified off-chain attributes.

Description

Method for Linking Off-Chain Attributes with Verifiable Credentials on Blockchain Method for Linking Off-Chain Attributes with Verifiable Credentials on Blockchain The present invention relates to a technology for blockchain-based Self-Sovereign Identity (SSI) and Verifiable Credential (VC), and in particular, to a method for linking the results of attribute verification performed in an off-chain environment to the VC attributes of the blockchain. The present invention utilizes smart contracts and blockchain networks to ensure the integrity and reliability of attribute information verified off-chain, and enables the use of this information in digital certificates and identity management services. Blockchain is a Distributed Ledger technology in which multiple nodes participating in a network share, verify, and manage data without a central server. This technology guarantees data integrity through decentralization, immutability, and transparency, and all transactions and data are stored in blocks linked in chronological order. Self-Sovereign Identity (SSI) is a decentralized identity management system that allows users to manage their own identities and credentials. In existing centralized identity systems, central organizations such as governments or corporations issued and managed users' identities, whereas SSI is designed to give users complete control over their identities. A Verifiable Credential (VC) is a verifiable credential in which an issuer grants a user specific qualifications or attributes, which the user can present to a verifier. The VC includes the issuer's digital signature, allowing the verifier to verify the authenticity of the credential. DID is registered on a blockchain or decentralized network to guarantee data transparency and integrity. A DID document contains information associated with the DID, such as a public key, allowing validators to verify metadata about the DID. Since DID documents are stored on a blockchain, manipulation or tampering of identity information can be prevented. In addition, DID is linked with Verifiable Credentials (VCs) to enable the integrated management of credentials issued by various issuing authorities. Users can collect attributes or credentials issued by various institutions in one place, store them in a digital wallet, and present them to validators whenever necessary. In this process, a DID Resolver links the VC or identity information associated with the user's DID, allowing the validator to verify the authenticity of the credentials. Figure 1 is a diagram showing how a blockchain smart contract links with an off-chain attribute verification service. In the embodiment of FIG. 1, the user has their identity verified by an off-chain verification agency, such as a bank, and is issued necessary attribute information, such as proof of income or deposit balance. The verification result is stored in the Web2 attribute verification service unit (200), and the user is issued a certificate that can be submitted to the blockchain. When a user links verified attribute information to the blockchain, the blockchain smart contract (100) processes this information. During this process, the DMPC management unit (110) has multiple participating nodes perform Decentralized Multi-Party Computation (DMPC) to safely process and verify external data. This is an essential step to ensure the reliability of externally input data and to confirm that it has not been tampered with. Subsequently, the attribute verification unit (120) verifies the validity of the attribute information received from off-chain. The verified attribute information is transmitted to the attribute certificate management unit (130), and the management unit generates a Verifiable Credential (VC) based on this data. The generated VC is stored in a digital wallet linked to the user's DID and can subsequently be utilized in various services. The response consensus unit (140) combines the verification results of multiple nodes to finally determine the integrity of the data, and the history is recorded on the blockchain. This ensures the transparency and reliability of all verification processes. Users can use the issued VC to access various services, such as the attribute certificate-based service unit (300). For example, when applying for a loan service, users can prove that their income level is above a certain standard through a zk-SNARKs-based zero-knowledge proof without disclosing a specific income amount. The loan service provider checks the authenticity of the information by viewing the attribute verification history recorded on the blockchain through the data transmission and reception unit (140) and proceeds with loan approval.