[CFRG] Re: RG Last Call on draft-irtf-cfrg-hybrid-kems-12 and draft-irtf-cfrg-concrete-hybrid-kems-04

[Daniel Van Geest <[e-mail]>]

I have reviewed both documents and submitted a number of PRs, mostly minor complaints about nits or clarity which I hope the authors address.

I have verified all test vectors in draft-irtf-cfrg-concrete-hybrid-kems.

The largest complaint I have is about the quality of the "randomness" test vectors: https://github.com/cfrg/draft-irtf-cfrg-concrete-hybrid-kems/issues/62

These test vectors could be improved to exercise expanded randomness slicing, rejection sampling, and endianness issues. Being a string of repeated bytes, the current randomness test vectors don't exercise any of that.

I think draft-irtf-cfrg-hybrid-kems-12.html is ready with nits, and draft-irtf-cfrg-concrete-hybrid-kems-04 is ready with nits and improved test vectors.

Thanks,
Daniel


________________________________
From: Nick Sullivan <[e-mail]>
Sent: Wednesday, July 08, 2026 11:24 AM
To: CFRG <[e-mail]>
Cc: [e-mail] <[e-mail]>
Subject: [CFRG] RG Last Call on draft-irtf-cfrg-hybrid-kems-12 and draft-irtf-cfrg-concrete-hybrid-kems-04

Dear CFRG,

This message starts a two-week RG Last Call on two related documents. The last
call ends on Wednesday July 22, 2026:

  Hybrid PQ/T Key Encapsulation Mechanisms (generic constructions)
  draft-irtf-cfrg-hybrid-kems-12
  https://www.ietf.org/archive/id/draft-irtf-cfrg-hybrid-kems-12.html

  Concrete Hybrid PQ/T Key Encapsulation Mechanisms
  draft-irtf-cfrg-concrete-hybrid-kems-04
  https://www.ietf.org/archive/id/draft-irtf-cfrg-concrete-hybrid-kems-04.html

Both are intended as Informational RFCs. Please reply on-list with your position
on each document: ready to publish as-is, ready with specific changes, or not
ready, together with the technical reasons. This feedback will help the chairs
judge whether the documents are ready for IRSG review and publication.

The scope and approach of this work were settled when the group adopted it well
over a year ago, and both drafts have developed on the list in the open since
then. This last call is about whether the text is technically correct and
complete, so please ground any objection in a specific problem with the
documents. Detailed comments are best filed as issues on the repositories
(https://github.com/cfrg/draft-irtf-cfrg-hybrid-kems,
https://github.com/cfrg/draft-irtf-cfrg-concrete-hybrid-kems) positions belong
here on the list.

Both documents were reviewed by the CFRG Crypto Review Panel ahead of this last
call. The reviews are on the CFRG and crypto-panel lists:

  Thomas Pornin (NCC Group), 3 June 2026, reviewed the generic framework with a
  focus on the constructions and reductions, and concluded that it describes a
  secure construction, with editorial and technical comments now reflected in -12.

  Virendra Kumar (Qualcomm), 8 June 2026, reviewed the generic framework for
  clarity, with notational comments now reflected in -12.

  Russ Housley (Vigil Security), 2 June 2026, reviewed both drafts and found the
  constructions and instantiations as specified.

The current revisions incorporate changes proposed by the panel's comments.

Thank you,
Nick, for the CFRG chairs