Re: [perpass] Consensus on algorithms/cipher suites in Opportunistic Security

Paul Wouters <paul@nohats.ca> Wed, 26 August 2015 19:09 UTC

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Date: Wed, 26 Aug 2015 15:09:34 -0400
From: Paul Wouters <paul@nohats.ca>
To: Kathleen Moriarty <kathleen.moriarty.ietf@gmail.com>
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Subject: Re: [perpass] Consensus on algorithms/cipher suites in Opportunistic Security
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On Tue, 25 Aug 2015, Kathleen Moriarty wrote:

> I posted a question to SAAG and would like to see where we are at on
> consensus around a statement that keeps showing up in drafts.
>
> If you could take a look at my message to SAAG (and the thread) and
> chime in there, it would be helpful to know where we are at.  I might
> be in the rough, but I'm not so sure that I am...
>
> https://mailarchive.ietf.org/arch/msg/saag/PXrRghfHM-OBj2Y2TniuKptpKCs

Actually, I agree with you. I do not like the use of "weaker algorithms"
for Opportunstic Security.

There is no valid reason to design anything that is "weaker" in strength
(eg keysize). I think what might have been meant is "unauthenticated"
versus "authenticated". And that also turns "weak" and "advanced"
attacker into "passive" and "active" attackers. I think that would be
more inline with the discussions we have had regarding opportunistic
security. I have never heard of a proposal from anyone that said "use
AES128 for opportunistc and AES256 for preconfigured security".

Paul