Glossary
Anonymity set — the crowd you hide in. When you spend, your proof says "one of the notes in the tree"; the larger and more active the pool, the stronger your privacy.
Commitment — the on-chain hash of a note that hides its contents (amount, token, owner) while binding them. Stored as a leaf in the Merkle tree.
Consolidation — merging several small notes into fewer large ones (a self-transfer), so you can make big private spends.
Merkle tree — the append-only tree of all note commitments. Spending proves your note's commitment is a leaf in it, without revealing which.
Note — a unit of private value: (token, amount, owner, randomness). Like a bill of private cash; only its owner can spend it.
Nullifier — a one-time tag revealed when a note is spent, recorded on-chain to prevent double-spending. Unlinkable to the note's commitment.
Owner key — a hash of your spend key that a note is bound to. Spending requires knowing the spend secret behind it.
Relayer — an optional service that submits your transaction and pays gas, reimbursed by an in-proof fee. Cannot forge a spend or read your notes.
Indexer — a service that caches on-chain events (leaves, nullifiers, blobs) so wallets sync quickly. A projection of public chain data.
Shielded pool — the on-chain vault + Merkle tree + nullifier set that holds all private value.
Spend key — your master secret, derived from a wallet signature, held in memory only. Authorizes spends.
Trusted setup — a one-time ceremony that produces the proving/verifying keys for a Groth16 circuit; its secret "toxic waste" must be destroyed.
Veil / deposit — moving a public token into the pool, where it becomes a private note.
Viewing key — a one-way subkey of your spend key that can decrypt your notes (read-only) but cannot spend. Used for compliance disclosure.
Withdraw / reveal — moving private value back out to a public address.
Zero-knowledge proof (Groth16) — a compact cryptographic proof that a private action is valid without revealing its details. Verified on-chain by the Solana program.