Credential Protocol

The Credential Protocol is a comprehensive technical framework developed by the Accountable Digital Identity Association (ADIA) for managing verifiable credentials within digital identity systems. This protocol defines how credentials are issued, verified, and managed throughout their lifecycle.

The protocol operates as an extension to the Aries issue-credential protocol and provides additional functionality specific to the ADIA ecosystem. It enables secure credential issuance between issuers and users while maintaining privacy and security controls.

Key features include:

• Credential metadata management
• Signature request/response handling
• Revocation capabilities
• Expiration management
• Integration with DID-based connections

Purpose and Scope:

• Standardizes credential issuance and verification workflows
• Defines message formats for credential operations
• Establishes roles and responsibilities for participating entities
• Provides audit trail capabilities through immutable metadata records

Technical Specifications:

• Uses JSON message formats for all protocol commands
• Implements state machine transitions for credential lifecycle
• Supports Base64 encoding for credential attachments
• Integrates with DIDComm messaging protocols

Implementation Requirements:

• Must be implemented by:
  • Issuer Agents
  • Cloud Agents
  • Service Provider Agents

Security Considerations:

• Requires secure DID-based connections between parties
• Implements signature verification
• Maintains audit trails through metadata
• Supports credential revocation and expiration

Interoperability Features:

• Compatible with Aries RFC 0036 (Issue Credential Protocol)
• Supports standard credential formats
• Uses common messaging patterns
• Enables cross-system credential verification

The protocol is actively maintained by the ADIA and serves as a critical component in their digital identity infrastructure, enabling secure and standardized credential management across the ecosystem.