# Eclipse Privacy

> Eclipse Privacy is a compliant USDC privacy pool on the Stellar network. You deposit a fixed amount of USDC behind a secret note, then withdraw to any address. A zero-knowledge proof (Groth16 over BN254) breaks the on-chain link between deposit and withdrawal, and is verified on-chain by Stellar's native host functions. Privacy is by proof; compliance is by design.

Eclipse Privacy runs on Stellar testnet today: a full deposit and withdrawal has settled live, with the proof verified on-chain. Proving happens entirely in the user's browser (snarkjs in a Web Worker), so no server ever sees the secret. The Merkle tree of deposits is a 20-level Poseidon tree, reconstructed by the client from an on-chain commitment log.

How it works, in three steps:
- Deposit: lock a fixed amount of USDC behind a secret note. The pool stores a commitment, never an identity.
- Prove: the browser builds a zero-knowledge proof that the user owns one of the deposits, without revealing which one.
- Withdraw: any fresh address claims the funds. On-chain, nothing ties the withdrawal back to the deposit.

Compliance model: Eclipse enforces a freeze list keyed by nullifier hash. A flagged note can be frozen so its funds cannot be withdrawn, stopping bad actors without a blocklist that would break everyone else's privacy. Anonymity is cryptographic and immediate; the anonymity set grows as more deposits enter the pool.

Stack: Circom + Groth16 (BN254) circuit, Soroban smart contract (Rust), Stellar Poseidon and BN254 host functions (protocol 27), React frontend with client-side proving.

## Links

- [Eclipse Privacy app](https://eclipseprivacy.xyz/): the live dApp on Stellar testnet
- [On-chain verifier contract](https://stellar.expert/explorer/testnet/contract/CBRICYFV2KXEN2Q224NUULGNKRUWVXBP2SEVHIEXXPHQVH7327TBUCTS): the Soroban contract that verifies each Groth16 proof on Stellar

## Optional

- [ZK Proofs on Stellar](https://developers.stellar.org/docs/build/apps/zk): Stellar's reference for BN254, Poseidon, and on-chain proof verification
- [Privacy on Stellar](https://developers.stellar.org/docs/build/apps/privacy): Stellar's privacy app guide