| A2A | Agent-to-Agent protocol — handshake for two agents to verify each other’s DIDs and exchange capabilities. |
| ADI | The Layer-2 blockchain IDA is built on (mainnet chain ID 8400). |
| Anoncrypt | DIDComm encryption mode where the sender is hidden from the recipient. |
| Authcrypt | DIDComm encryption mode where the sender is authenticated to the recipient. |
| Autonomy Level | Integer 1–5 declared on an Agent DID describing the scope of action it is authorized to take. |
| BBS+ | Signature scheme that supports selective disclosure of fields. |
| Capability Token (IBCT) | Short-lived JWT granting an agent narrow, time-bounded permissions. |
| Controller | The DID(s) authorized to update a DID Document. |
| DID | Decentralized Identifier — globally unique self-sovereign identifier (W3C DID Core 1.0). |
| DID-Auth | Authentication by signing a server-issued nonce with a DID’s authentication key. |
| DID Document | JSON-LD object resolved from a DID containing keys, authentication methods, and service endpoints. |
| DIDComm | DIF protocol for end-to-end encrypted DID-to-DID messaging. |
| Groth16 | Succinct zk-SNARK proving system used by IDA’s ZK predicates. |
| Holder | Role that holds and presents Verifiable Credentials. |
| IBCT | Identity-Bound Capability Token. |
| Issuer | Role that signs and issues Verifiable Credentials about a Subject. |
| JWS / JWT | JSON Web Signature / Token — used for VC proofs and session access. |
| MCP-I | Model Context Protocol with Identity. |
| MPC Wallet | Multi-Party Computation wallet — splits the private key into shares. |
| Predicate | A logical statement (e.g., age_gte 18) used as the relation in a ZK proof. |
| Presentation | A bundle of one or more credentials signed by the holder for a verifier. |
| Selective Disclosure | Revealing only certain fields of a credential, hiding the rest. |
| Status List 2021 | W3C method for compact on-chain revocation status. |
| Subject | The entity a credential describes. |
| Trust Registry | On-chain registry of trusted issuers and their schemas. |
| Trust Score | Numeric 0–100 reputation computed by the AgentTrustRegistry. |
| Verifiable Credential (VC) | Cryptographically signed attestation per W3C VC Data Model 2.0. |
| Verifiable Presentation (VP) | Holder-signed bundle of VCs. |
| Verifier | Role that requests and validates presentations or ZK proofs. |
| ZKP | Zero-Knowledge Proof — proof of a statement without revealing the underlying data. |
