Re: [Cfrg] DH, not ECDH, subgroup attack question

Peter Gutmann <pgut001@cs.auckland.ac.nz> Tue, 28 January 2020 23:11 UTC

Return-Path: <pgut001@cs.auckland.ac.nz>
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 68A791200FF for <cfrg@ietfa.amsl.com>; Tue, 28 Jan 2020 15:11:47 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.197
X-Spam-Level:
X-Spam-Status: No, score=-4.197 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=auckland.ac.nz
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 QOyzhv16xOrT for <cfrg@ietfa.amsl.com>; Tue, 28 Jan 2020 15:11:45 -0800 (PST)
Received: from mx4-int.auckland.ac.nz (mx4-int.auckland.ac.nz [130.216.125.246]) (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 26ABC1200EB for <cfrg@irtf.org>; Tue, 28 Jan 2020 15:11:44 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=auckland.ac.nz; i=@auckland.ac.nz; q=dns/txt; s=mail; t=1580253106; x=1611789106; h=from:to:cc:subject:date:message-id:references: in-reply-to:mime-version; bh=A9BruVR/vbRtx8D/kvSTwlWeD9AdlTENKQdcITFqSvA=; b=ua6WFSEuLiWrJ7Puof/cCUebIIfqx4opYK/Q4qK6FsctGjB2LBXP75gm T3ESJwCR6vsJpFUnPkPNCHABN+ztQKTOKPeH8MHUdgpjMcJHI8t8+y1P0 sStKRVIThYFiZCtxnPM6F/UYScKhM9V10TuDF8R2JsneIDmhHAYoRB7rd YHCqgHhwuwN/cm+fMtpFQpGu1kH+dGynI12c1dO29zMnRSQjqjbFG0TCi ar8BIvDV1SPeosL4DECvk53A7EGoA0U+ajpbOz2xU4tj3vMmP1vOH2ZhF 2wpNKUxpJVWOEv0EmD5L3YWDf5sPetxyMX6DIHc3vGqFPQ/wHTGj7kTvd Q==;
X-IronPort-AV: E=Sophos;i="5.70,375,1574074800"; d="scan'208,217";a="112144891"
X-Ironport-HAT: MAIL-SERVERS - $RELAYED
X-Ironport-Source: 10.6.3.5 - Outgoing - Outgoing
Received: from exchangemx.uoa.auckland.ac.nz (HELO uxcn13-tdc-d.UoA.auckland.ac.nz) ([10.6.3.5]) by mx4-int.auckland.ac.nz with ESMTP/TLS/AES256-SHA; 29 Jan 2020 12:11:42 +1300
Received: from uxcn13-ogg-d.UoA.auckland.ac.nz (10.6.2.5) by uxcn13-tdc-d.UoA.auckland.ac.nz (10.6.3.5) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 29 Jan 2020 12:11:41 +1300
Received: from uxcn13-ogg-d.UoA.auckland.ac.nz ([10.6.2.5]) by uxcn13-ogg-d.UoA.auckland.ac.nz ([10.6.2.5]) with mapi id 15.00.1395.000; Wed, 29 Jan 2020 12:11:41 +1300
From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: Richard Barnes <rlb@ipv.sx>, Robert Moskowitz <rgm-sec@htt-consult.com>
CC: IRTF CFRG <cfrg@irtf.org>
Thread-Topic: [Cfrg] DH, not ECDH, subgroup attack question
Thread-Index: AQHV1jBHnLamOfsn2Eygypmf6oDIjQ==
Date: Tue, 28 Jan 2020 23:11:40 +0000
Message-ID: <1580253099227.42957@cs.auckland.ac.nz>
References: <93a5af6f-e40b-a3aa-ef1e-17ac1feb9ace@htt-consult.com>, <CAL02cgRkbcrcgvNzueqQeGEFxMX_pO=JuEuys5txZYqcff3kxw@mail.gmail.com>
In-Reply-To: <CAL02cgRkbcrcgvNzueqQeGEFxMX_pO=JuEuys5txZYqcff3kxw@mail.gmail.com>
Accept-Language: en-NZ, en-GB, en-US
Content-Language: en-NZ
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [130.216.158.4]
Content-Type: multipart/alternative; boundary="_000_158025309922742957csaucklandacnz_"
MIME-Version: 1.0
Archived-At: <https://mailarchive.ietf.org/arch/msg/cfrg/QnzWSEpMsEEy8tUlIuLQOGP0zQc>
Subject: Re: [Cfrg] DH, not ECDH, subgroup attack question
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: Tue, 28 Jan 2020 23:11:47 -0000

Just a nitpick, just saw the thread, this is a DH subgroup attack question, not an ECDH subgroup attack question.


Peter.?