IETF Logo Mail Archive

Re: [Cfrg] I-D Action: draft-irtf-cfrg-spake2-06.txt

Nico Williams <nico@cryptonector.com> Mon, 03 December 2018 23:15 UTC

Return-Path: <nico@cryptonector.com>
X-Original-To: cfrg@ietfa.amsl.com
Delivered-To: cfrg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id F07E2130E68 for <cfrg@ietfa.amsl.com>; Mon, 3 Dec 2018 15:15:25 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2
X-Spam-Level:
X-Spam-Status: No, score=-2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_NONE=-0.0001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cryptonector.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 89UpkfDNSUHx for <cfrg@ietfa.amsl.com>; Mon, 3 Dec 2018 15:15:24 -0800 (PST)
Received: from golden.birch.relay.mailchannels.net (golden.birch.relay.mailchannels.net [23.83.209.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 3848F130E41 for <cfrg@ietf.org>; Mon, 3 Dec 2018 15:15:23 -0800 (PST)
X-Sender-Id: dreamhost|x-authsender|nico@cryptonector.com
Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id A837628384A; Mon, 3 Dec 2018 23:15:21 +0000 (UTC)
Received: from pdx1-sub0-mail-a26.g.dreamhost.com (unknown [100.96.19.78]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id 7A242283973; Mon, 3 Dec 2018 23:15:09 +0000 (UTC)
X-Sender-Id: dreamhost|x-authsender|nico@cryptonector.com
Received: from pdx1-sub0-mail-a26.g.dreamhost.com (pop.dreamhost.com [64.90.62.162]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384) by 0.0.0.0:2500 (trex/5.16.2); Mon, 03 Dec 2018 23:15:21 +0000
X-MC-Relay: Neutral
X-MailChannels-SenderId: dreamhost|x-authsender|nico@cryptonector.com
X-MailChannels-Auth-Id: dreamhost
X-Versed-Cellar: 0ec0efd66c5671ad_1543878909653_2784163140
X-MC-Loop-Signature: 1543878909653:3855835116
X-MC-Ingress-Time: 1543878909652
Received: from pdx1-sub0-mail-a26.g.dreamhost.com (localhost [127.0.0.1]) by pdx1-sub0-mail-a26.g.dreamhost.com (Postfix) with ESMTP id 0CBB77FA48; Mon, 3 Dec 2018 15:15:08 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=cryptonector.com; h=date :from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=cryptonector.com; bh=h6Rtxin41nIcB/ UfGrMwjDSOZIo=; b=ToGUjC8KA5VHyC7XCv/fXuOpEzn9HGL40/wxy6uBPavlew ZatiNzzZKJ9tqDlINCZj71x/ezECy8sbUkb5eWFc2kgyYw0G86KBMv8Z1+Qermuq k2AyL4MtcWLyNKYIFBhYw37gJUTnSCZ+7krTFUpggoX9AcoQ7ik1fzT6lttIE=
Received: from localhost (unknown [24.28.108.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: nico@cryptonector.com) by pdx1-sub0-mail-a26.g.dreamhost.com (Postfix) with ESMTPSA id E4C027FA47; Mon, 3 Dec 2018 15:15:05 -0800 (PST)
Date: Mon, 03 Dec 2018 17:15:03 -0600
X-DH-BACKEND: pdx1-sub0-mail-a26
From: Nico Williams <nico@cryptonector.com>
To: "Scott Fluhrer (sfluhrer)" <sfluhrer@cisco.com>
Cc: Greg Hudson <ghudson@mit.edu>, "cfrg@ietf.org" <cfrg@ietf.org>
Message-ID: <20181203231502.GJ15561@localhost>
References: <153434759643.14400.9943392813751876897@ietfa.amsl.com> <20180815154402.GP40887@kduck.kaduk.org> <20181201211038.GA15561@localhost> <c0799f2c-8079-c066-9a19-c9640f00c93e@mit.edu> <20181201233630.GB15561@localhost> <1a71a4a5-65a5-7504-f0a4-403d7e46629b@mit.edu> <20181202191531.GC15561@localhost> <20181203222107.GI15561@localhost> <0e3c7af326de474e90325056335237f2@XCH-RTP-006.cisco.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <0e3c7af326de474e90325056335237f2@XCH-RTP-006.cisco.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
X-VR-OUT-STATUS: OK
X-VR-OUT-SCORE: -100
X-VR-OUT-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedtkedrudefvddgtdejucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuggftfghnshhusghstghrihgsvgdpffftgfetoffjqffuvfenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvffukfhfgggtuggjfgesthdtredttdervdenucfhrhhomheppfhitghoucghihhllhhirghmshcuoehnihgtohestghrhihpthhonhgvtghtohhrrdgtohhmqeenucfkphepvdegrddvkedruddtkedrudekfeenucfrrghrrghmpehmohguvgepshhmthhppdhhvghloheplhhotggrlhhhohhsthdpihhnvghtpedvgedrvdekrddutdekrddukeefpdhrvghtuhhrnhdqphgrthhhpefpihgtohcuhghilhhlihgrmhhsuceonhhitghosegtrhihphhtohhnvggtthhorhdrtghomheqpdhmrghilhhfrhhomhepnhhitghosegtrhihphhtohhnvggtthhorhdrtghomhdpnhhrtghpthhtohepnhhitghosegtrhihphhtohhnvggtthhorhdrtghomhenucevlhhushhtvghrufhiiigvpedt
Archived-At: <https://mailarchive.ietf.org/arch/msg/cfrg/toDkVRGrDuw5GtrTuPk5ya5qI_A>
Subject: Re: [Cfrg] I-D Action: draft-irtf-cfrg-spake2-06.txt
X-BeenThere: cfrg@irtf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Crypto Forum Research Group <cfrg.irtf.org>
List-Unsubscribe: <https://www.irtf.org/mailman/options/cfrg>, <mailto:cfrg-request@irtf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/cfrg/>
List-Post: <mailto:cfrg@irtf.org>
List-Help: <mailto:cfrg-request@irtf.org?subject=help>
List-Subscribe: <https://www.irtf.org/mailman/listinfo/cfrg>, <mailto:cfrg-request@irtf.org?subject=subscribe>
X-List-Received-Date: Mon, 03 Dec 2018 23:15:30 -0000

On Mon, Dec 03, 2018 at 10:51:30PM +0000, Scott Fluhrer (sfluhrer) wrote:
> I do not believe that works as a PAKE, as it would allow an adversary
> to test multiple potential passwords from a single exchange.

Ay, you're right.  We end up with

Ka = G*(x r)
Kb = G*(H(P) y)

and then B can test P values until B finds a P where Kb matches Ka.

Well done!

Nico
--

v2.23.0 | Report a Bug | By Email