Verifiable Credential Data Integrity

Verifiable Credential Data Integrity is a specification that defines mechanisms for ensuring the authenticity and integrity of digital documents, particularly verifiable credentials, using cryptographic proofs. The standard enables the creation and verification of digital signatures and other mathematical proofs to protect document integrity while supporting features like selective disclosure and unlinkability.

At its core, the specification implements a three-step process for creating cryptographic proofs:

1. Transformation - Converting input data into a standardized format
2. Hashing - Generating a unique cryptographic identifier
3. Proof Generation - Creating the actual cryptographic protection

Key differentiating capabilities include:

• Support for both proof sets (multiple independent signatures) and proof chains (ordered sequence of dependent signatures)
• Flexible transformation algorithms that enable the same signature to work across different data formats
• Built-in selective disclosure capabilities for privacy-preserving verification
• Cryptographic agility to support algorithm upgrades over time

Purpose and Scope:

• Defines standard methods for adding cryptographic proofs to digital documents
• Enables verification of document authenticity and integrity
• Supports both simple signatures and complex proof chains
• Provides framework for implementing privacy-preserving features

Technical Specifications:

• Uses JSON-LD for data modeling and context definition
• Supports multiple cryptographic suites through modular design
• Implements proof purposes to prevent signature misuse
• Requires specific proof properties: type, verificationMethod, proofPurpose
• Uses Multibase encoding for cryptographic values

Implementation Requirements:

• Must implement core algorithms for Add Proof and Verify Proof
• Must validate all JSON-LD contexts against known good values
• Must implement proper error handling for proof verification
• Must support caching of context documents for security

Security Considerations:

• Enforces cryptographic agility through versioned suites
• Supports cryptographic layering for long-term security
• Requires validation of proof purposes and verification methods
• Implements protections against dataset poisoning attacks

Interoperability Features:

• Standard JSON-LD contexts for cross-implementation compatibility
• Common proof format supporting multiple cryptographic suites
• Transformation algorithms enabling cross-format verification
• Standardized error codes and handling

Current Adoption:

• Implemented by W3C Verifiable Credentials ecosystem
• Supported by multiple digital identity platforms
• Used in production systems for credential issuance and verification
• Active development of new cryptographic suites