Markdown Version | Session Recording

Session Date/Time: 23 Jul 2024 22:30

pquip

Summary

The pquip working group meeting covered several documents related to post-quantum cryptography (PQC). Discussions included the "PQC for Engineers" draft, hybrid terminology, hybrid signature spectrums, NIST's post-quantum standardization efforts, migration use cases, and hash-based signature schemes. The meeting addressed potential last calls for some drafts and future directions for the working group.

Key Discussion Points

• PQC for Engineers Draft:

  • Authors believe the draft is nearly complete and proposed a working group last call after IETF 120.
  • The draft serves as an IETF-focused PQC primer.
  • Participants were encouraged to review the draft and provide feedback, specifically identifying any missing topics or areas for improvement.

• Hybrid Terminology Draft:

  • The draft standardizes terminology for post-quantum/traditional hybrids.
  • A working group last call was conducted in February, resulting in updates to the draft.
  • There was a discussion of the scope of the document and where to address more complex aspects of hybrid security, potentially in another draft.
  • A second working group last call is likely.

• Hybrid Signature Spectrums Draft:

  • This document describes different security properties and spectrums related to hybrid signature construction.
  • Discussions were held around separability, generality, and artifact locations within hybrid signatures.
  • The draft includes language on why one would use a hybrid signature, a hybrid PQ traditional signature, versus not going PQ at all, or going directly to PQ and not doing hybrid at all.
  • Consensus on these additions may be challenging.
  • Discussion regarding strong non-separable (fused) hybrid signatures, including potential use cases.
  • A working group last call may flush out any further issues.

• NIST Post-Quantum Cryptography Standardization Update:

  • NIST provided an update on its post-quantum cryptography standardization process.
  • Four algorithms are in the standardization track: ML-KEM (Kyber), ML-DSA (Dilithium), Falcon, and SPHINCS+.
  • Round 4 candidates are being evaluated, with a focus on Classically Enhanced McEliece (Classic McEliece), BIKE, and HQC.
  • On-ramp signature candidates are also being evaluated.
  • Relaxation of restrictions around state copying in SP 800-208 is planned.
  • A special-purpose publication discussing ML-KEM deployment scenarios is forthcoming.

• Migration Use Cases Taxonomy Draft:

  • This document aims to guide engineers in choosing appropriate algorithms and parameters for post-quantum migration based on factors like duration, backwards compatibility, and protocol negotiation capabilities.
  • The draft was revised to address previous feedback.
  • The decision tree was updated to rely on objective measurements rather than subjective opinions.
  • Exploration of a "pessimistic migration" approach is under consideration.

• Hash-Based Signature Schemes Draft:

  • Document on how to manage the stateful part of hash-based signature schemes like XMSS and LMS.
  • Feedback was received to add when stateful schemes are appropriate in the first place.
  • The authors propose adopting the draft.

• PQC Hackathon:

  • Positive work being done at the PQC Hackathon with new GitHub actions enabling interoperability testing.

Decisions and Action Items

• Action Item: Participants to review "PQC for Engineers" draft and provide feedback on missing topics or areas for improvement.
• Action Item: Authors of the "Hybrid Terminology" draft to proceed with a second working group last call.
• Action Item: Authors of the "Hybrid Signature Spectrums" draft to prepare for a working group last call.
• Action Item: Britta Hale to push to CFRG a few strong, non-separable construction which use P-56 and MLDSA.
• Action Item: Alexander to include information about PQC Hackathon to the mailing list.

Next Steps

• Continue discussions on the mailing list for all documents.
• Begin working group last calls for drafts where consensus is reached.
• Consider adoption of drafts when appropriate.
• Monitor progress of NIST's post-quantum cryptography standardization efforts.