Re: [babel] Babel-MAC: Blake2s is 128-bits by default

Juliusz Chroboczek <jch@irif.fr> Tue, 17 November 2020 23:47 UTC

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Date: Wed, 18 Nov 2020 00:47:13 +0100
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From: Juliusz Chroboczek <jch@irif.fr>
To: Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen?= <toke@toke.dk>
Cc: babel@ietf.org, Valery Smyslov <valery@smyslov.net>
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Subject: Re: [babel] Babel-MAC: Blake2s is 128-bits by default
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>> Toke and Dave originally suggested adding Blake2s to Babel-HMAC [...]

> Note sure that I quite agree with your history here,

It's quite likely I got it wrong, sorry if that's the case.

> I'm not actually opposed to 128-bit signatures per se, although I would
> be more comfortable if someone with a crypto background could weigh in
> with an opinion on this.

Valery, perhaps you could help?

>> 1. Toke agrees to switch to 128-bit Blake2s signatures;

> I think what would happen is that Bird would support both.

Ok.

You didn't address the most important question: do you agree with modifying
the RFC-to-be so that the SHOULD applies to 128-bit signatures, and
clarifying the information model that the "Blake2s" algorithm implies
128-bit signatures?

-- Juliusz