Re: [MLS] DeriveKeyPair IKM size
Simon Ser <contact@emersion.fr> Fri, 15 March 2024 14:18 UTC
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Date: Fri, 15 Mar 2024 14:18:23 +0000
To: Rohan Mahy <rohan.ietf@gmail.com>
From: Simon Ser <contact@emersion.fr>
Cc: "mls@ietf.org" <mls@ietf.org>
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Subject: Re: [MLS] DeriveKeyPair IKM size
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On Friday, March 15th, 2024 at 15:07, Simon Ser <contact@emersion.fr> wrote: > > Note that [XWing], also contraindicates the SHOULD in [HPKE] Section > > 7.1.3, because 2432 octets of entropy is excessive, and 32 octets is > > expected to be sufficient. > > That's not my reading of the spec: the HPKE RFC says that the "ikm parameter > given to DeriveKeyPair() SHOULD have length at least Nsk". The "at least" part > is key here: feeding a larger parameter satisfies the SHOULD. Nevermind: XWing defines a HPKE KEM scheme, and stipulates that a smaller ikm than the HPKE RFC requires is fine. But that's orthogonal to the MLS discussion here.
- [MLS] DeriveKeyPair IKM size Simon Ser
- Re: [MLS] DeriveKeyPair IKM size Rohan Mahy
- Re: [MLS] DeriveKeyPair IKM size Simon Ser
- Re: [MLS] DeriveKeyPair IKM size Simon Ser