Nullmask

Privacy-preserving DeFi protocol powered by zero-knowledge proofs

Nullmask enables shielded deposits, transfers, withdrawals, and swaps on EVM chains. Users interact with a standard wallet — the protocol intercepts transactions, generates zero-knowledge proofs client-side, and submits them through a relayer to hide the sender's identity.

Funds are held in a UTXO-based privacy pool secured by Poseidon2 commitments and Merkle membership proofs.

Quick Links

Section	Description
What is Nullmask?	High-level introduction to the protocol
How It Works	End-to-end architecture walkthrough
Protocol Specification	Cryptographic details, algorithms, and proofs
Smart Contract Reference	Solidity API for deposits, transfers, and swaps
RPC API Reference	JSON-RPC methods exposed by the proxy
Developer Guide	Build and run locally
User Guide	Step-by-step instructions for end users

Key Features

• Shielded Transfers — Send tokens privately without revealing sender, recipient, or amount on-chain

• Shielded Swaps — Execute Uniswap V2 swaps without exposing trading activity

• Private Deposits & Withdrawals — Move funds in and out of the shielded pool with ZK-verified proofs

• Multi-Chain — Deployed on Ethereum, Arbitrum, MegaETH, Base, and BSC

• Standard Wallet UX — No special wallet needed; works with MetaMask and any EIP-1559 compatible wallet

• Hardware Wallet Support — Full security without extracting spending authority from the device

• ERC-20 Support — Shield any supported ERC-20 token alongside native ETH

• Built-in Compliance — Deposit screening with retrospective taint recovery via revocation keys

Tech Stack

Layer	Technology
ZK Circuits	Noir + Barretenberg
Smart Contracts	Solidity 0.8.28, Hardhat v3, OpenZeppelin v5
Frontend	Next.js 15, React 19, TailwindCSS 4
Backend Services	Fastify 5, Node.js 24
Web3	Viem, Wagmi, tRPC
Monorepo	Turborepo, pnpm
Storage	LMDB (persistent state)
Code Quality	Biome, TypeScript 5.9, knip