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Re: [Cfrg] I-D Action: draft-irtf-cfrg-dragonfly-03.txt

Robert Ransom <rransom.8774@gmail.com> Tue, 04 February 2014 19:41 UTC

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Date: Tue, 04 Feb 2014 11:41:37 -0800
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From: Robert Ransom <rransom.8774@gmail.com>
To: Dan Harkins <dharkins@lounge.org>
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Cc: cfrg@ietf.org, David McGrew <mcgrew@cisco.com>
Subject: Re: [Cfrg] I-D Action: draft-irtf-cfrg-dragonfly-03.txt
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On 2/4/14, Dan Harkins <dharkins@lounge.org> wrote:

>   This is mentioned in section 6.3 of RFC 5931 (dragonfly as an EAP
> method), knowledge of r where PE = r * G can enable a dictionary
> attack. But knowledge of r requires doing a discrete logarithm. A discrete
> logarithm is assumed to be "computationally infeasible" and you're talking
> about doing 2^40 of them!?!

<http://cr.yp.to/papers.html#nonuniform> is relevant here.  It
discusses several other ‘attacks’ of this general type, and explains
why they should not be taken seriously.


Robert Ransom

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