The fhEVM architecture provides the foundation for confidential smart contracts on EVM-compatible blockchains. At its core is FHE, a cryptographic technique enabling computations directly on encrypted data, ensuring privacy at every stage.
This system relies on three key types:
The public key: used for encrypting data.
The private key: used for decryption and securely managed by the Key Management System or KMS
The evaluation key: enabling encrypted computations performed by the coprocessor.
The fhEVM leverages Zama's TFHE library, integrating seamlessly with blockchain environments to address transparency, composability, and scalability challenges. Its hybrid architecture combines:
On-chain smart contracts for encrypted state management and access controls.
Off-chain coprocessors for resource-intensive FHE computations.
The Gateway to coordinate between blockchain, KMS, and coprocessors.
The KMS for secure cryptographic key management and proof validation.
This architecture enables developers to write private, composable smart contracts using symbolic execution and zero-knowledge proofs, ensuring data confidentiality and computational integrity.
For a detailed exploration of the fhEVM architecture, including components, workflows, and deployment models, see Architecture Overview.