Laundry Protocol

Key Features
Process Flow Nullifier Mechanism

Laundry Protocol is a non-custodial privacy solution for Ethereum and Arbitrum. It uses zero-knowledge proofs to break the on-chain link between deposit and withdrawal addresses.

• Zero-Knowledge Proofs: Withdraw without revealing your deposit address
• Non-Custodial: You maintain control of your funds at all times
• Cross-Chain: Atomic swaps between Ethereum and Arbitrum
• Compliance Ready: Optional proof generation for regulatory requirements

1. Deposit: User generates a random secret and nullifier, computes the commitment, and deposits funds along with the commitment.
2. Anonymity Set: The commitment is added to a Merkle tree. As more users deposit, the anonymity set grows.
3. Withdrawal: User generates a ZK proof that they know a secret corresponding to a commitment in the tree, without revealing which one.

The nullifier prevents double-spending. When you withdraw, you reveal the nullifier (but not the secret). The contract stores all used nullifiers and rejects any withdrawal with a previously used nullifier.