Re: [CFRG] Compact NIST curves in HPKE

[Ilari Liusvaara <[e-mail]>]

On Thu, Sep 15, 2022 at 12:34:30PM -0700, Dan Harkins wrote:
> 
> > BTW - I always thought CFRG was supposedly a research group (and would
> > not deal with code-point assignments, which are an IETF issue).
> 
>   Well HPKE is a product of the CFRG and it created a registry so I guess
> research groups can deal with code-point assignments.
> 
>   To answer Ilari, I think the CFRG Crypto Panel is looking at my draft
> as a precursor to a possible adoption call. So things are progressing,
> albeit very slowly.


Looking at the IANA registry for the HPKE KEMs, it is listed to be
"Specification Required". From RFC8126 / BCP26, here is what that
entails:

"For the Specification Required policy, review and approval by a
designated expert (see Section 5) is required, and the values and
their meanings must be documented in a permanent and readily
available public specification, in sufficient detail so that
interoperability between independent implementations is possible."

And:

"The intention behind "permanent and readily available" is that a
document can reasonably be expected to be findable and retrievable
long after IANA assignment of the requested value.  Publication of an
RFC is an ideal means of achieving this requirement, but
Specification Required is intended to also cover the case of a
document published outside of the RFC path, including informal
documentation."


So:

1) The designated experts listed in IANA registry are Christopher Wood
   and Richard Barnes.
2) Do I-Ds count as permanent? Those are available (from the IETF
   itself) even after expiry.
3) IMO, the specification in draft-harkins-cfrg-dnhpke-02 section 4.1
   is sufficiently detailed for interop.


The other changes in the draft look to be much more involved, and do
not look to be relevant for COSE, at least not at the current time.


> > On 2022-09-15 12:18 p.m., Ilari Liusvaara wrote:
> > > During IETF 113 (about half a year ago), there was presentation of
> > > additions to HPKE. Especially, adding compact versions of NIST curves.
> > > I think having compact NIST curves in HPKE would be useful for the COSE
> > > WG, which is working on integrating HPKE to COSE (CBOR Object Signing
> > > and Encryption).
> > > 
> > > 
> > > What's the current status? I see that during IETF 113, the issue seemed
> > > to be that there were no designated experts assigned, but this has been
> > > fixed since. Is the current issue that nobody has formally asked to
> > > assign the codepoints as described by draft-harkins-cfrg-dnhpke-02
> > > section 4.1? Or something else?



-Ilari