Re: [COSE] [jose] Fwd: New Version Notification for draft-reddy-cose-jose-pqc-kem-00.txt

[Ilari Liusvaara <[e-mail]>]

On Tue, Mar 05, 2024 at 05:03:23PM +0530, tirumal reddy wrote:
> We have published a new draft
> https://www.ietf.org/archive/id/draft-reddy-cose-jose-pqc-kem-00.html, that
> describes the conventions for using Post-Quantum Key Encapsulation
> Mechanisms (PQ-KEMs) within JOSE and COSE.  Although this mechanism could
> be used with any PQ-KEM, this document focuses on Module-Lattice-based Key
> Encapsulation Mechanisms (ML-KEMs).
> 
> Comments and Suggestions are welcome.

I can't make heads or tails of how this is supposed to work. Whatever it
is, it would certainly fail to be fully-specified. Moreover, I don't
think it complies with JWE either.

The way KEMs operate is extremely similar to how ECDH-ES works. So the
way to add KEMs is to copy ECDH-ES (fully specified if needed) and make
small modifications required for it to work.

The two main modifications compared to ECDH-ES are:

1) The shared secret is generated by encapsulation/decapsulation instead
   of ECDH operation.
2) New header parameter for KEM ciphertext, as it is octet string and
   not a key.

The usual KDF structuctures of COSE/JOSE could be reused as-is. However,
for COSE, if HPKE ends up binding alg from one layer higher, then it
would make sense to do that here too (and if doing fully-specified
ECDH-ES, there too).


> ---------- Forwarded message ---------
> From: <[e-mail]>
> Date: Sun, 3 Mar 2024 at 10:32
> Subject: New Version Notification for draft-reddy-cose-jose-pqc-kem-00.txt
> To: Tirumaleswar Reddy.K <[e-mail]>, Aritra Banerjee <
> [e-mail]>, Hannes Tschofenig <[e-mail]>,
> Hannes Tschofenig <[e-mail]>
> 
> 
> A new version of Internet-Draft draft-reddy-cose-jose-pqc-kem-00.txt has
> been
> successfully submitted by Tirumaleswar Reddy and posted to the
> IETF repository.
> 
> Name:     draft-reddy-cose-jose-pqc-kem
> Revision: 00
> Title:    Post-Quantum Key Encapsulation Mechanisms (PQ KEMs) for JOSE and
> COSE




-Ilari