Privacy-preserving Paymaster

This is a project write-up for a privacy-preserving paymaster that lets users withdraw from mixers such as Tornado Cash into a fresh address without holding ETH for gas. Users generate a zero-knowledge proof of the withdrawal and encode it in the paymaster data, and the paymaster validates the proof, executes the withdrawal, pays the gas fee, and deploys a new smart account to receive the funds. The build uses the ERC4337 standard, contracts inherited from eth-infinitism with overridden validation logic, a modified trampoline browser extension to create the UserOp, and open-source Tornado Cash code for deposits and proof generation. The contracts have been deployed to Goerli, Polygon Mumbai, Optimism Goerli, Gnosis Chain, Linea, Mantle testnet and Scroll testnet.