fhEVM by Zama is a fully homomorphic encryption protocol designed to write confidential smart contracts. It enables developers to create confidential onchain applications in Solidity, ensuring that the state remains encrypted end-to-end, from the moment a transaction is submitted to when smart contracts are processing it. fhEVM supports a wide range of operations, including encrypted booleans, 4-bit integers, 64-bit integers, and encrypted addresses. It introduces a new asynchronous decryption API, allowing smart contracts to initiate decryption requests via an oracle and receive answers through callbacks. This method offloads decryption tasks, freeing up resources and improving performance. fhEVM also includes a standard library with contracts such as ERC20 and DAO, designed for easy extension and customization. The API allows decryption batches of multiple types, enabling the decryption of different encrypted data types in the same callback. It features a new permissions model for managing access to encrypted data, enhancing security and control. fhEVM is compatible with future versions and across various chains, ensuring long-term stability and broad usability. It also supports the integration of zero-knowledge proofs for inputs and new types, further enhancing its capabilities.
