W3C Decentralized Identifiers (DIDs)

Decentralized Identifiers (DIDs) are a new type of globally unique identifier designed to enable individuals and organizations to generate their own identifiers using systems they trust. DIDs enable verifiable, decentralized digital identity without relying on centralized registries, identity providers, or certificate authorities.

A DID consists of three parts:

• A URI scheme identifier (did:)
• The identifier for the DID method
• The method-specific identifier

Core capabilities include:

• Decentralized - No central registration authority required
• Persistent - Can remain unchanged regardless of changes in underlying systems
• Cryptographically Verifiable - Ownership can be proven using cryptographic proofs
• Resolvable - Can be resolved to a DID Document containing metadata
• Privacy-Preserving - Subjects control how much information is revealed

The specification defines:

1. Purpose and Scope:

• Provides a standard format for decentralized identifiers
• Enables cryptographic proof of control without central authorities
• Supports interoperable identity management across different systems

2. Key Technical Specifications:

• DID Syntax: did:<method-name>:<method-specific-id>
• DID Document structure containing:
  • Verification methods (e.g., public keys)
  • Service endpoints
  • Authentication mechanisms
• DID Resolution process to retrieve DID Documents
• Multiple representation formats (JSON, JSON-LD)

3. Implementation Requirements:

• Must implement at least one DID method
• Must support standard DID syntax
• Must be able to resolve DIDs to DID Documents
• Must implement required security considerations
• Must support verification methods and authentication

4. Security Considerations:

• Cryptographic proof of control
• Key management and rotation
• Revocation mechanisms
• Authentication protocols
• Integrity protection

5. Interoperability Features:

• Standard DID syntax across methods
• Common DID Document format
• Standardized resolution process
• Cross-platform compatibility
• Multiple representation formats

6. Current Adoption:

• Over 100 experimental DID method specifications
• 32+ experimental method implementations
• 46 implementations submitted for conformance testing
• Growing adoption in digital identity systems

The specification represents a fundamental building block for decentralized identity infrastructure, enabling self-sovereign identity management while maintaining security and privacy.