Verifiable Credential

Every Verifiable Credential contains an embedded cryptographic proof that enables any verifying party to detect unauthorized modifications. The proof is generated by the issuer signing a hash of the credential's contents using their private key.

• Uses digital signature schemes such as EdDSA, ECDSA, or BBS+
• Any alteration to the credential invalidates the proof immediately
• Supports selective disclosure where only specific claims are revealed
• Proofs can be embedded directly (JWT) or linked externally (Linked Data Proofs)

The VC ecosystem operates on a three-party trust model that eliminates the need for direct communication between the issuer and verifier. The holder (agent) acts as an intermediary, presenting credentials issued by a trusted issuer to any verifier that trusts that issuer.

• Issuer: Creates and signs the credential with its private key
• Holder: Stores and presents the credential, controls disclosure
• Verifier: Validates the issuer's signature and credential status
• Trust is established through cryptographic verification, not direct API calls

Credentials can be revoked or expired without requiring the holder to surrender the physical credential. Verifiers check revocation registries or status lists during verification to ensure a credential is still valid.

• StatusList2021: A compact bitstring-based revocation mechanism
• Revocation registries can be hosted on decentralized ledgers or verifiable data registries
• Supports time-bound credentials with built-in expiration timestamps
• Enables real-time credential suspension for compromised agent identities

In multi-agent systems, VCs enable secure, automated trust establishment between autonomous agents without human intervention. An agent can present a VC proving its authorization level, capabilities, or organizational affiliation before engaging in collaborative tasks.

• Prevents agent impersonation attacks through cryptographic identity binding
• Enables delegated authorization: Agent A proves it acts on behalf of Entity B
• Supports capability-based security models for tool access control
• Integrates with DIDComm messaging for encrypted credential exchange

A globally unique, persistent identifier that enables self-sovereign identity for agents without requiring a centralized registration authority. DIDs are the subject field of a Verifiable Credential, cryptographically binding the attestation to a specific entity. Unlike email addresses or usernames, DIDs remain under the agent's control and can be resolved to a DID Document containing public keys and service endpoints.

A cryptographic method enabling one agent to prove a statement is true without revealing the underlying data. In the context of Verifiable Credentials, ZKPs enable selective disclosure—an agent can prove it is authorized to access a resource without exposing its full credential. Key techniques include:

• zk-SNARKs: Succinct proofs with constant verification time
• BBS+ Signatures: Enable multi-message selective disclosure
• Range Proofs: Prove a value falls within a threshold without revealing it

A secure, isolated area within a main processor that guarantees confidentiality and integrity of code and data loaded inside it. TEEs provide hardware-backed assurance that an agent's Verifiable Credential private keys and signing logic cannot be tampered with, even by a compromised operating system. Common implementations include Intel SGX, AMD SEV, and ARM TrustZone.

A security mechanism that allows an agent to generate irrefutable cryptographic proof of its current software stack and identity. Before a verifier accepts a Verifiable Credential, remote attestation confirms the presenting agent is running unmodified, trusted code. This closes the gap between possessing a valid credential and proving the runtime environment is trustworthy.

A cryptographic scheme where a private key is split into shares distributed among multiple agents, requiring a minimum threshold to collaborate to produce a valid digital signature. This prevents a single compromised agent from unilaterally issuing or revoking Verifiable Credentials. Common in multi-agent governance models where credential issuance requires consensus from a quorum of authorized signers.

A dynamic network structure that maps and quantifies transitive trust relationships between agents based on historical interactions, endorsements, and behavioral consistency. Trust graphs extend Verifiable Credentials beyond binary verification by computing reputation scores and confidence levels. An agent with credentials vouched for by multiple trusted issuers accumulates higher trust weight in the graph.