Notes & Vaults

A note is the unit of private balance inside a Siphon vault.

Note structure

Each note contains:

The commitment inserted into the Merkle tree is:

commitment = Poseidon(value, Poseidon(nullifier, secret))

Only the user who generated the note knows the nullifier and secret.

Deposits

When you deposit through the Entrypoint:

1. Tokens move into the asset-specific Vault.
2. A new commitment is inserted as a Merkle leaf.
3. Note secrets are generated and stored locally (optionally encrypted and synced to the server).

Spends

Spending a note requires a Groth16 proof that:

• Proves Merkle membership of the input commitment(s)
• Reveals nullifier hash(es) to prevent double-spend
• Binds the recipient and any swap parameters in public signals

Observers see that some note was spent — not which deposit it came from.

Spendable balance

Your balance is not a single on-chain number. The dapp reconstructs it by:

1. Matching local notes against indexed Merkle leaves
2. Excluding notes whose nullifiers appear on-chain
3. Summing remaining note values

The indexer (siphon-indexer) makes this a single HTTP query instead of thousands of eth_getLogs calls.

Vault operations