Presentation Exchange

Presentation Exchange is a protocol specification that standardizes how verifiers can request proofs and how holders can submit them in digital identity systems. The specification enables format-agnostic presentation of claims and credentials between parties.

The standard defines two primary data formats:

• Presentation Definition - Used by verifiers to specify proof requirements
• Presentation Submission - Used by holders to describe how submitted proofs satisfy the requirements

Key features include:

• Format-agnostic design supporting JSON Web Tokens, Verifiable Credentials, and other JSON-serializable claim formats
• Transport protocol independence (works with OpenID Connect, DIDComm, etc.)
• Flexible proof requirement specification through input descriptors
• Support for selective disclosure and predicate proofs
• Credential status verification capabilities

Technical Analysis:

1. Purpose and Scope:

• Enables structured request and submission of digital credentials/proofs
• Provides format-agnostic data models for proof exchange
• Supports complex proof requirements and combinations
• Facilitates interoperable credential verification

2. Key Technical Specifications:

• Uses JSONPath for referencing credential data
• Leverages JSON Schema for input validation
• Defines Input Descriptor format for specifying requirements
• Supports nested and complex submission requirements
• Includes Feature system for optional capabilities

3. Implementation Requirements:

• Must support JSON Schema Draft 7
• Must implement specified JSONPath syntax subset
• Must handle required security considerations
• Must support base objects before optional features
• Must validate against provided JSON schemas

4. Security Considerations:

• Protection against malicious regular expressions
• Safeguards for JSONPath function extensions
• Proper handling of JSON Schema validation
• Secure processing of nested submissions
• Protection against replay attacks

5. Interoperability Features:

• Format-agnostic credential handling
• Transport protocol independence
• Standardized embedding locations
• Flexible proof requirement specification
• Support for multiple credential formats

6. Current Adoption:

• Ratified by the Decentralized Identity Foundation
• Supported by major digital identity implementations
• Used in production identity systems
• Integrated with OpenID Connect and DIDComm
• Active community development and maintenance