**Session Date/Time:** 17 Mar 2025 06:00

# CFRG Meeting Minutes

## Summary

The CFRG meeting covered a range of topics, including updates on existing documents, discussions on chem combiners, presentations on BBS signatures, anonymous rate-limited credentials, sigma protocols, FrodoKEM, hybrid key encapsulation mechanisms, ECDHPSI, and franking mechanisms for instant messaging. Key discussions revolved around the process for developing cryptographic standards in the IRTF, the need for community involvement, and the prioritization of work items.

## Key Discussion Points

*   **CFRG as part of IRTF:** Emphasized that CFRG is part of the IRTF, which connects research and policy to IETF work. Focus is on solving problems, not standardizing solutions.
*   **Chem Combiner Process:** An update on the hybrid chem combiner process was given, including questions posed to the group about the draft's progress and the need for additional help.
*   **BBS Signatures:** Presentations covered the main BBS signatures document and extensions for blind signatures and pseudonyms. Privacy concerns related to pseudonyms were raised.
*   **Anonymous Rate Limited Credentials (ARC):** A proposal for ARC was presented as a privately verifiable credential for rate-limiting in privacy pass. A suggestion was made to develop a generic framework for anonymous credentials.
*   **Sigma Protocols:** The benefits of standardizing Zero Knowledge Proofs, especially Sigma Protocols, through Fia-Shamir transformation, were presented.
*   **FrodoKEM Standardization:** An update on the ISO standardization effort for FrodoKEM was presented, along with a call for action for CFRG to consider standardization.
*   **Hybrid KEMs:**  Concrete and generic hybrid KEM constructions were discussed. Concerns were raised about the usefulness of the various instantiations.
*   **ECDHPSI:** An update on the ECDHPSI protocol, including potential attack scenarios and solutions.
*   **MIMI Franking:** A description of the franking mechanism used for abuse reporting in MIMI (instant messaging).

## Decisions and Action Items

*   **Chem Combiners:**
    *   Richard Barnes and Martin Thompson volunteered to help with the collaborative writing process.
    *   Discuss on the mailing list whether to pause or stop the work on chem combiners due to velocity and concerns about scope.
*   **FrodoKEM:** Start a discussion on the mailing list to determine the need for IETF standardization.

## Next Steps

*   Continue discussion on the mailing list regarding:
    *   The future of the chem combiner draft.
    *   Potential standardization of FrodoKEM.
    *   Direction for the anonymous credentials framework.
*   Release new ID for FrodoKEM.
*   Publish draft specifications of Sigma Protocols along with reference implementations.
*   Schedule a public side meeting for Ntru.