W3C Verifiable Credentials Data Model

The W3C Verifiable Credentials Data Model is a specification that defines how to express credentials on the Web in a way that is cryptographically secure, privacy-respecting, and machine-verifiable. It provides a standard data model for representing digital versions of physical credentials like driver's licenses, passports, and educational certificates.

Key features that differentiate this standard:

• Cryptographically verifiable claims and proofs
• Privacy-preserving features like selective disclosure and zero-knowledge proofs
• Flexible data model that supports extension and interoperability
• Support for both human and machine verification
• Decentralized architecture that doesn't require intermediaries

Purpose and Scope:
The standard aims to:

• Define a data model for expressing verifiable credentials and presentations
• Enable secure, privacy-preserving credential exchange
• Support interoperability between credential issuers, holders, and verifiers
• Allow credentials to be verified without contacting the original issuer
• Enable selective disclosure of credential information

Key Technical Specifications:

• Core Data Model components:
  • credentialSubject - Claims about one or more subjects
  • issuer - Entity that issued the credential
  • proof - Cryptographic proof of authenticity
  • type - Credential type definition
  • @context - JSON-LD context for semantic meaning

Implementation Requirements:

• Must implement the base data model and required properties
• Must support at least one proof format (e.g. JWT or Data Integrity)
• Must include proper @context and type declarations
• Must validate credentials according to the specification rules
• Should implement privacy-preserving features where possible

Security Considerations:

• Cryptographic proofs must be properly implemented and verified
• Privacy risks like correlation must be mitigated
• Secure storage and transmission of credentials required
• Key management and revocation must be handled properly
• Implementation-specific security measures needed

Interoperability Features:

• Standard JSON-LD contexts for semantic interoperability
• Multiple proof formats supported
• Extensible data model
• Standard verification procedures
• Common credential status methods

Current Adoption:
The standard has broad industry adoption and support from:

• Major technology companies
• Government agencies
• Educational institutions
• Identity and credential providers
• Open source projects and communities

The specification provides a robust foundation for implementing verifiable credentials while maintaining flexibility for different use cases and implementation approaches.