Meeting Minutes – LF Decentralized Trust European Chapter Meeting - October
Date: 22-10-2025
Time: 4PM CET
Location: Online
Chairperson: Dominik Zyskowski
Agenda Items
- Overview of Zama’s FHE architecture and ERC-7984 standard
- Confidential transactions and interoperability
- Ecosystem adoption and roadmap
- Next steps and coordination
Key Takeaways
- Zama’s FHE coprocessor architecture enables confidential transactions on any public blockchain without modifying the base layer VM.
- The ERC-7984 standard defines a technology-agnostic interface for confidential tokens, using “handles” to abstract away the underlying encryption method (FHE, TEE, MPC).
- The primary goal is to drive adoption of ERC-7984 to solve ecosystem fragmentation, which is the main barrier to confidential blockchain use cases.
- Zama is live on Sepolia, launching on Ethereum mainnet in weeks, and expanding to other EVMs in Q1/Q2 2025.
Topics
The Problem: Blockchain Transparency vs. Confidentiality
- Public blockchains are transparent by design, requiring all data to be visible for validators to verify transactions.
- This transparency is a barrier for enterprise use cases (e.g., banks, supply chains) that require data privacy.
- Zama’s solution uses Fully Homomorphic Encryption (FHE) to allow computation on encrypted data without decryption.
Zama’s FHE Coprocessor Architecture
- Compatibility: Avoids modifying the base blockchain VM, making it compatible with any EVM.
- On-Chain (e.g., Ethereum):
- Smart contracts manipulate “handles,” which are pointers to encrypted data.
- Emit events to the coprocessor for all FHE operations (e.g.,
add(handleA, handleB)).
- Store the Access Control List (ACL) for decryption permissions.
- Off-Chain (FHE Coprocessor):
- A decentralised L3 network of coprocessors executes FHE operations.
- Stores encrypted data and reaches consensus on results before returning an encrypted output handle to the smart contract.
- Decentralised Verification: The on-chain computational graph is public, allowing independent re-execution and verification.
Input Flow:
- Encrypt Data – User encrypts data (e.g., 5) in their browser.
- Generate ZK Proof – User creates a zero-knowledge proof that they know the clear value.
- Call Gateway – User sends encrypted data and ZK proof to Zama’s gateway.
- Gateway Validation – Verifies proof, stores encrypted data, and returns a signed handle.
- Smart Contract Call – User calls the contract with the handle and gateway signature.
- On-Chain Validation – Smart contract verifies the gateway signature before using the handle.
Decryption Flow (KMS):
- The decryption key is sharded across MPC nodes to prevent any single party from decrypting data.
- Process:
- User requests decryption.
- KMS nodes check the on-chain ACL for permission.
- If approved, nodes perform partial re-encryption.
- User aggregates and decrypts the result with their key.
ERC-7984: The Confidential Token Standard
- Defines a technology-agnostic interface for confidential tokens.
- Key Feature: Replaces integer amounts with “handles” referencing encrypted data.
- Design: Developed with OpenZeppelin for strong alignment with existing token standards.
Ecosystem Adoption:
- Custody: DFNS, Taurus implementing; 2 others in discussion.
- Bridges: LayerZero adopting for a confidential Omnichain Fungible Token (OFT).
- Wallets: Ongoing discussions.
- Regulatory Support: Built-in mechanism for smart contracts to authorise third-party decryption for regulatory audits.
Next Steps
- Ghazi (Zama):
- Provide details on the gateway signature authority.
- Connect with Thomas (LF Decentralized Trust) to discuss ERC-7984 standardisation.
- Thomas (LF Decentralized Trust):
- Connect Zama with LFDT’s standardisation contacts.
- Dominik (Espeo):
- Distribute the meeting recording internally.