| aghost | The base unit of the GHOST token. 1 GHOST = 10^18 aghost. Equivalent to wei in Ethereum. |
| Access proof | A non-destructive ZK proof that proves knowledge of a commitment without consuming it. Used for persistent key access. |
| AssetGuard | Smart contract that maintains the whitelist of tokens authorized for Ghost Protocol operations. |
| Blinding factor | A random value included in the commitment preimage to prevent grinding attacks. |
| BN254 | The elliptic curve (also called alt_bn128) used for Groth16 proof verification. Supported natively by Ethereum precompiles. |
| CometBFT | The Byzantine Fault Tolerant consensus engine used by Specter. Provides instant finality. |
| Commitment | A Poseidon hash of secret inputs (secret, nullifierSecret, tokenIdHash, amount, blinding). Stored in the Merkle tree. |
| CommitRevealVault | The central smart contract that orchestrates all Ghost Protocol commit and reveal operations. |
| CommitmentTree | An append-only Merkle tree (depth 20, ~1M capacity) that stores all commitments. |
| Ghost Protocol | Specter's core privacy primitive — a commit-reveal system using ZK proofs for unlinkable token transfers. |
| GhostERC20 | A privacy-enabled ERC20 token with vault-controlled mint/burn functions. |
| Ghostmint | The precompile at address 0x0808 that enables smart contracts to mint and burn native GHOST tokens. |
| GHOST token | The native gas and staking token of the Specter network. |
| Groth16 | A zero-knowledge proof system with constant-size proofs (256 bytes) and fast verification. |
| Merkle tree | A hash tree structure used to prove set membership. Specter uses depth-20 Poseidon Merkle trees. |
| NativeAssetHandler | The smart contract authorized to call the Ghostmint precompile on behalf of the CommitRevealVault. |
| Nullifier | A value derived from the user's nullifierSecret and leaf index. Registered on-chain to prevent double-reveals. |
| NullifierRegistry | Smart contract that tracks spent nullifiers. |
| Open Protocol | A variant of Ghost Protocol for public data commitments (no privacy, but integrity and provenance). |
| Phantom Keys | A key management system using access proofs for persistent, reusable key storage. |
| Policy | A smart contract implementing IRevealPolicy that enforces conditions on reveals (timelocks, restrictions, etc.). |
| PolicyRegistry | Smart contract that maps commitments to their associated reveal policies. |
| Poseidon | A ZK-friendly hash function used for commitments and Merkle tree nodes. |
| PoseidonT3 | The on-chain Poseidon hash library (arity 2, ~55KB bytecode). |
| Reveal | The process of proving knowledge of a commitment's preimage and minting fresh tokens. |
| Root updater | A relayer service that maintains the Merkle tree off-chain and submits updated roots on-chain. |
| ShardedTreeRegistry | A registry managing 16 parallel Merkle trees for scaling. |
| snarkjs | A JavaScript library for generating and verifying Groth16 ZK proofs. |
| specterd | The Specter node binary (CLI + daemon). |
| Trusted setup | The ceremony that generates the Groth16 proving and verification keys. |