Architectural overview

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.