FHEVM v0.8 - September 2025

Highlights

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This version brings several new features that makes the FHEVM more scalable, secure, and developer-friendly:

• New KMS connector for modular integration

• Compressed ciphertexts for lighter payloads

• Flexible extraData field for richer apps

• Post-quantum ML-KEM512 for faster, smaller decrypts

• Stronger chain resilience & ERC-7995 compliance

New features

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• New KMS connector: Introduced a new Key Management System connector to improve modularity and integration.

• Compressed ciphertext support: Added support for compressed ciphertexts in both the SnS worker and KMS, reducing payload sizes.

• Generic extraData field: Gateway functions, events, and signed structs now include a generic extraData field to improve extensibility and custom data support.

• SepoliaConfig update: Introduced the protocolId() function to support protocol identification.

Improvements

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• ERC-7995 compatibility: Updated the Oracle’s expected callback function interface for compliance, following ERC-7995.

Breaking Changes

Oracle callback function signature now requires the following format:

function callbackExample(
  uint256 requestID,
  bytes memory cleartexts,
  bytes memory decryptionProof
) external;

• Reduced user decrypt payload size: Migrated to ML-KEM512 (128-bit equivalent post-quantum security), significantly reducing decrypt response sizes and allowing more responses per block.

• Host listener: Implemented reorganization handling in the host listener for increased chain resilience.

• Library storage layout: Adjusted storage layout to align with the standard’s guidelines.

Resources

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• GitHub Release

• Documentation