Re: [Cfrg] revised requirements for new curves

"Paterson, Kenny" <Kenny.Paterson@rhul.ac.uk> Mon, 08 September 2014 15:10 UTC

Return-Path: <Kenny.Paterson@rhul.ac.uk>
X-Original-To: cfrg@ietfa.amsl.com
Delivered-To: cfrg@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 812F71A8866 for <cfrg@ietfa.amsl.com>; Mon, 8 Sep 2014 08:10:15 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.902
X-Spam-Level:
X-Spam-Status: No, score=-1.902 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham
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 aZ6-FNF0fS-S for <cfrg@ietfa.amsl.com>; Mon, 8 Sep 2014 08:10:12 -0700 (PDT)
Received: from emea01-db3-obe.outbound.protection.outlook.com (mail-db3lrp0075.outbound.protection.outlook.com [213.199.154.75]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 948AF1A886E for <cfrg@irtf.org>; Mon, 8 Sep 2014 08:10:10 -0700 (PDT)
Received: from DBXPR03MB383.eurprd03.prod.outlook.com (10.141.10.15) by DBXPR03MB384.eurprd03.prod.outlook.com (10.141.10.20) with Microsoft SMTP Server (TLS) id 15.0.1019.16; Mon, 8 Sep 2014 15:10:08 +0000
Received: from DBXPR03MB383.eurprd03.prod.outlook.com ([10.141.10.15]) by DBXPR03MB383.eurprd03.prod.outlook.com ([10.141.10.15]) with mapi id 15.00.1015.018; Mon, 8 Sep 2014 15:10:08 +0000
From: "Paterson, Kenny" <Kenny.Paterson@rhul.ac.uk>
To: Stephen Farrell <stephen.farrell@cs.tcd.ie>, "cfrg@irtf.org" <cfrg@irtf.org>
Thread-Topic: [Cfrg] revised requirements for new curves
Thread-Index: AQHPy07l29iFHJb+W02/iURsgQFUO5v3T7KAgAAYXYA=
Date: Mon, 8 Sep 2014 15:10:08 +0000
Message-ID: <D0338465.2C999%kenny.paterson@rhul.ac.uk>
References: <D0333B6F.2C8CF%kenny.paterson@rhul.ac.uk> <540DC067.9070205@cs.tcd.ie>
In-Reply-To: <540DC067.9070205@cs.tcd.ie>
Accept-Language: en-GB, en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
user-agent: Microsoft-MacOutlook/14.4.3.140616
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [134.219.227.30]
x-microsoft-antispam: BCL:0;PCL:0;RULEID:;UriScan:;
x-forefront-prvs: 03283976A6
x-forefront-antispam-report: SFV:NSPM; SFS:(6009001)(199003)(189002)(24454002)(51444003)(479174003)(31966008)(79102001)(85306004)(46102001)(83506001)(74662001)(74482001)(106356001)(77982001)(105586002)(101416001)(2656002)(85852003)(106116001)(20776003)(74502001)(76482001)(107046002)(83322001)(99396002)(19580395003)(19580405001)(76176999)(54356999)(21056001)(90102001)(92566001)(95666004)(107886001)(2501002)(87936001)(66066001)(83072002)(4396001)(86362001)(80022001)(92726001)(81342001)(81542001)(97736003)(36756003)(50986999); DIR:OUT; SFP:; SCL:1; SRVR:DBXPR03MB384; H:DBXPR03MB383.eurprd03.prod.outlook.com; FPR:; MLV:sfv; PTR:InfoNoRecords; A:1; MX:1; LANG:en;
Content-Type: text/plain; charset="us-ascii"
Content-ID: <9CEA39DAD3A4C94598473C6DE26D3711@eurprd03.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: rhul.ac.uk
Archived-At: http://mailarchive.ietf.org/arch/msg/cfrg/gohUWP_20wM3V2_XaNbBqHi_76Q
Subject: Re: [Cfrg] revised requirements for new curves
X-BeenThere: cfrg@irtf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Crypto Forum Research Group <cfrg.irtf.org>
List-Unsubscribe: <http://www.irtf.org/mailman/options/cfrg>, <mailto:cfrg-request@irtf.org?subject=unsubscribe>
List-Archive: <http://www.irtf.org/mail-archive/web/cfrg/>
List-Post: <mailto:cfrg@irtf.org>
List-Help: <mailto:cfrg-request@irtf.org?subject=help>
List-Subscribe: <http://www.irtf.org/mailman/listinfo/cfrg>, <mailto:cfrg-request@irtf.org?subject=subscribe>
X-List-Received-Date: Mon, 08 Sep 2014 15:10:15 -0000

Hi Stephen,

On 08/09/2014 15:42, "Stephen Farrell" <stephen.farrell@cs.tcd.ie>; wrote:

>Hiya,
>
>Good job and good to see this progressing towards completion.
>Thanks for both.
>
>On 08/09/14 11:23, Paterson, Kenny wrote:
>> 
>> SE5. Required: each set of curve parameters should be generated by a
>> well-defined procedure that allows only a limited and quantified amount
>>of
>> flexibility. If the selected procedure involves the choice of an initial
>> seed, then the seed will be selected by multiple independent parties
>>using
>> a procedure having the property that no collusion of all but one or
>>fewer
>> of the parties can exert any control over the chosen seed. [RC]
>
>A clarification question: the above reads a bit like the result
>has to be a curve that hasn't yet been documented. I assume that
>its ok if e.g. 25519 and/or one of msft's are picked and that this
>is not meant to rule those out.

That's correct - it's not meant to rule these out. The intention is that,
for a specific, existing curve like Curve25519 or one of the MSR curves,
this requirement would mean the publication of a clear selection rationale
and an evaluation of how much flexibility was exercised during the
selection. 

>It might be worth stating that e.g.
>along the lines of "Note that SE5 does not rule out selection of
>an already documented curve or curves should there be consensus
>that this requirement has been met sufficiently."

OK, this could certainly be added.

>
>If you do mean to rule those out, then I think that really would
>need to be crystal clear.
>
>Other than that:
>
>On IN1 and IN2 I agree with William's comment. And since that
>is to the effect that those don't help or hinder selections
>I'm ok with the text as-is.

OK, good to know.

>On IP1, I do agree with the intent, but that might need to be
>reworded to keep everyone happy - one can never know for sure
>that royalty-free anything is possible. But I'm ok with the
>wording as-is, since adding the equivalent of "as far as its
>possible to know" doesn't matter so much given that CFRG cannot
>afaik yet do the impossible;-)

Understood. So some fine-tuning might be merited here.

Cheers

Kenny 

>
>Ta,
>S.