Architecture of fhEVM

1. Data Flow

• Encryption: Input data is encrypted off-chain using FHE-compatible libraries or SDKs (e.g., fhevmjs).

• Computation: Encrypted data is processed on-chain using FHE-based instructions within the fhEVM runtime.

• Decryption/Re-encryption: Outputs can be decrypted or re-encrypted securely for off-chain use or further computation.

2. Execution Model

fhEVM extends the EVM opcode set to include encrypted operations while preserving compatibility with traditional EVM functionalities. Key aspects:

• Instruction Handling: Specialized FHE instructions for arithmetic, logical, and bitwise operations.

• Gas Optimization: Enhanced mechanisms to minimize computational overhead associated with FHE.

• Encrypted State Persistence: Stores encrypted state variables in persistent contract storage.

The fhEVM sets a new standard for privacy and security in blockchain computing by integrating Fully Homomorphic Encryption into the Ethereum Virtual Machine. It provides developers with the tools to build privacy-preserving, scalable, and efficient decentralized applications while maintaining compatibility with the broader Ethereum ecosystem. By enabling encrypted data processing natively, fhEVM opens up new possibilities for blockchain applications across finance, healthcare, AI, and more.

For more details and implementation:

• Source Code: Cypher GitHub Repository