10.7 zk-Bridge
BitNet’s zk-Bridge architecture adds a privacy-preserving layer to cross-chain bridges by integrating zk-SNARKs. Users can transfer assets without revealing their source, destination, or wallet address.
How It Works
1. Deposit
Assets are deposited into a bridge smart contract.
A commitment hash is generated and stored:
commitment = Hash(secret, recipient, amount)
2. zk-SNARK Proof Generation
Off-chain, users generate a proof showing ownership of a valid unspent deposit.
The proof hides identity, source chain, and amount.
3. Withdrawal
The user submits a zk-proof and nullifier (prevents double-spending).
The contract verifies the proof and releases the funds anonymously.
Architecture
Acts as middleware, not a full bridge replacement.
Compatible with EVM chains using Solidity and Circom-based verifiers.
Supports modular integration into existing bridge UI/UX.
Benefits
Unlinkable Transfers: Breaks connection between deposit and withdrawal events.
DeFi Composability: Can be used with private DEXes, lending protocols, and DAOs.
Anonymity Set: Mimics privacy features of full ZK systems like Tornado Cash.
Implementation Challenges
zk-proof generation is still compute-intensive.
Requires robust, decentralized relayer networks.
Complex UX (managing secrets, nullifiers) must be abstracted for users.
Last updated