[Cfrg] using hash2curve in a protocol

Dan Harkins <dharkins@lounge.org> Wed, 24 July 2019 18:05 UTC

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Date: Wed, 24 Jul 2019 11:05:12 -0700
From: Dan Harkins <dharkins@lounge.org>
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Subject: [Cfrg] using hash2curve in a protocol
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   The hash-to-curve draft is still a work in progress but I want to
use it to fix a broken protocol. The protocol in question is EAP-pwd
defined in RFC 5931. It does a "hunting and pecking loop" method
of hashing to a curve that is similar, but worse, than the technique
described in RFC 7664. (The method of obtaining a secret element in
a MODP group is similarly broken). It is susceptible to side channel
attack and I want to use the hash-to-curve draft to fix it.

   To that end I have a new draft out that uses the Simplified SWU
method from -04 of the hash-to-curve draft:


I would greatly appreciate any review of this draft and solicit
comments. This is definitely a work in progress too but I hope that
as hash-to-curve congeals this draft can follow hot on its heels.