#Triangle of Trust: Foundation of Verifiable Credentials

#Introduction

The Triangle of Trust forms the core relationship model that enables verifiable credentials to function effectively in digital identity systems. This trust framework creates a secure, reliable ecosystem for digital credential exchange by defining clear roles and responsibilities for each participant.

In today's increasingly digital world, establishing trusted relationships without traditional paper credentials presents significant challenges. The Triangle of Trust addresses these challenges by providing a standardized approach to credential verification that maintains security, privacy, and user control.

#Key Components

The Triangle of Trust consists of three primary entities:

#Issuer

The Issuer creates and signs verifiable credentials, establishing their authenticity and provenance.

Role and Responsibilities:

• Creates credentials based on verified information
• Cryptographically signs credentials using their private keys
• Maintains and publishes their public keys and identifiers
• Establishes credential schemas and formats
• Revokes credentials when necessary

Examples of issuers include government agencies, educational institutions, employers, certification bodies, and other authoritative sources.

#Holder

The Holder receives, stores, and controls credentials, presenting them to verifiers when needed.

Role and Responsibilities:

• Securely stores credentials in digital wallets
• Maintains control over when and how credentials are shared
• Selectively discloses credential information as needed
• Manages multiple credentials from different issuers
• May generate verifiable presentations that combine multiple credentials

The holder is typically an individual, but could also be an organization or even an IoT device.

#Verifier

The Verifier requests and validates credentials presented by holders.

Role and Responsibilities:

• Requests specific credentials or proofs from holders
• Validates cryptographic signatures to ensure authenticity
• Checks credential status (active, expired, revoked)
• Verifies issuer identity and trustworthiness
• Evaluates credential content against verification policies
• Makes trust decisions based on verification results

Examples of verifiers include service providers, employers, government agencies, educational institutions, and online platforms.

#The Verification Process

The verification process represents the critical trust establishment mechanism within the Triangle of Trust. This process involves several key steps:

1. Credential Request: The verifier requests specific credentials or proofs from the holder based on their verification requirements.

2. Presentation Creation: The holder, with consent, generates a verifiable presentation containing the requested credential information.

3. Presentation Submission: The holder sends the verifiable presentation to the verifier through a secure channel.

4. Signature Verification: The verifier validates the cryptographic signatures on both the presentation (holder's signature) and the contained credentials (issuer's signatures).

5. Issuer Validation: The verifier confirms the issuer's identity by checking their decentralized identifier (DID) against a trusted registry.

6. Credential Status Check: The verifier checks if the credential is still valid and has not been revoked using status services or verification registries.

7. Policy Enforcement: The verifier applies domain-specific verification policies to evaluate the credential content.

8. Trust Decision: Based on all verification results, the verifier makes a trust decision about whether to accept the credential and grant access to the holder.

#Vidos Services in the Verification Ecosystem

Vidos focuses on providing robust, configurable services specifically designed for the Verifier role in the Triangle of Trust.

#Core Verification Services

Vidos offers several specialized services that work together to support comprehensive verification:

#Authorizer

The Authorizer service manages access control policies for verification processes, determining:

• Who can request verification
• What types of credentials can be verified
• Under what conditions verification can occur

#Resolver

The Resolver locates and retrieves essential verification resources:

• Issuer DID documents and public keys
• Credential schemas and context definitions
• Verification registries and status services

#Verifier

The Verifier service performs the cryptographic validation of credentials:

• Validates digital signatures
• Checks proof formats and methods
• Verifies the integrity of the credential data
• Confirms the credential structure matches expected schemas

#Validator

The Validator evaluates credential content against domain-specific rules:

• Checks required credential fields and values
• Validates dates, identifiers, and other attributes
• Applies custom business logic to credential data
• Enforces compliance with verification policies

#Integration in the Triangle of Trust

Vidos services integrate into the Triangle of Trust by providing the technical infrastructure needed by verifiers to establish trust relationships with issuers and holders:

1. Trust Anchor Establishment: Vidos services connect to trusted registries to confirm issuer identities.

2. Credential Format Support: Vidos verifier supports multiple credential formats (JSON-LD, JWT, mDocs), enabling interoperability across the ecosystem.

3. Configurable Trust Rules: Vidos validator enables verifiers to define custom rules for what constitutes a trusted credential.

4. Audit and Compliance: Vidos services provide detailed verification logs to support compliance requirements.

5. Privacy Enhancement: Vidos supports selective disclosure and zero-knowledge proof verification methods to enhance holder privacy.

#Implementation Considerations

When implementing verification services within the Triangle of Trust, several important considerations should be addressed:

#Security Best Practices

• Implement secure communication channels for credential exchange
• Use up-to-date cryptographic methods and libraries
• Apply the principle of least privilege to verification processes
• Validate all inputs to prevent injection attacks
• Implement rate limiting to prevent denial-of-service attacks
• Regularly audit verification logs for suspicious activity

#Privacy Considerations

• Only request the minimum credentials necessary for verification
• Support selective disclosure to minimize data exposure
• Implement appropriate data retention policies
• Provide clear notice about how verification data will be used
• Consider privacy regulations (GDPR, CCPA) when designing verification processes

#Interoperability Challenges

• Support multiple credential formats and proof methods
• Implement widely adopted standards (W3C VC, DID)
• Participate in interoperability testing and certification
• Design for extensibility to accommodate emerging standards
• Consider cross-domain verification requirements

#Conclusion

The Triangle of Trust provides the foundational model for secure, privacy-preserving credential exchange in digital identity systems. By clearly defining the roles and responsibilities of issuers, holders, and verifiers, this model enables trustworthy digital interactions without requiring centralized authorities.

Vidos services strengthen the verifier role within this triangle by providing specialized, configurable verification capabilities that adapt to diverse use cases while maintaining security and interoperability. By leveraging these services, verifiers can establish robust trust relationships with credential issuers and holders, enabling a wide range of secure digital identity applications.

#Related Resources

• W3C Verifiable Credentials Data Model