fhevm

FHEVM is the core framework of the Zama Confidential Blockchain Protocol. It brings Fully Homomorphic Encryption (FHE) to EVM-compatible blockchains so that smart contracts can operate on encrypted data directly on-chain, combining confidentiality with composability. Key guarantees described in the README: - End-to-end encryption of transactions and state: transaction data is encrypted and not visible to observers. - Composability and data availability on-chain: state is updated while remaining encrypted. - No impact on existing dApps and state: encrypted state coexists with public state. Main features: - Privacy by design for decentralized applications on Ethereum. - Solidity integration: contracts are written like standard Solidity, with compatibility with existing toolchains such as Hardhat (Foundry noted as coming soon). - Programmable privacy: developers choose what is encrypted and encode access control in contracts. - Encrypted integers with up to 256 bits of precision. - A full set of operators (arithmetic, comparison, ternary-if, boolean), with no stated limit on consecutive FHE operations. - Security: the underlying FHE scheme is described as quantum-resistant, with decryption managed through a key management system using multi-party computation. - Symbolic execution of FHE computations on the host chain, with actual encrypted computation offloaded asynchronously to a coprocessor. Repository structure: - gateway-contracts and host-contracts: smart contracts for the gateway between on-chain and off-chain components and for orchestrating FHE workflows on the host chain. - coprocessor: Rust-based implementation for FHE operations. - kms-connector: interface for integrating with Key Management Services. - charts, golden-container-images, test-suite: Helm deployment configurations, base Docker images, and end-to-end integration tests. Example use cases mentioned include confidential transfers, tokenization, blind auctions, on-chain games, confidential voting, and encrypted decentralized identifiers. Resources include official documentation, a whitepaper, examples, and the Awesome Zama list. The project is distributed under the BSD-3-Clause-Clear license; the FAQ notes that commercial use requires a patent license from Zama, and contributions require signing a Contributor License Agreement.