OpenZeppelin

About

OpenZeppelin is one of the longest-running smart contract security firms and the maintainer of the OpenZeppelin Contracts library that underpins much of the EVM ecosystem. Its audit practice covers major L1/L2 protocols and has included extensive work on ZK rollup smart contract and bridge layers, publishing many reports on its blog. Its strength is protocol and smart contract review at scale; for pure circuit-level cryptanalysis, teams often pair it with a circuit-specialist firm.