Re: [TLS] AAED ciphers: AES-GCM vs AES-EAX/AES-CCM: a meta-analysis

Michael Clark <michael@metaparadigm.com> Thu, 25 December 2014 01:37 UTC

Return-Path: <michael@metaparadigm.com>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A29AF1A6F68 for <tls@ietfa.amsl.com>; Wed, 24 Dec 2014 17:37:10 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.468
X-Spam-Level:
X-Spam-Status: No, score=-1.468 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, IP_NOT_FRIENDLY=0.334, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_DKIM_INVALID=0.01, T_RP_MATCHES_RCVD=-0.01] autolearn=no
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 nfC3f-Eqluqe for <tls@ietfa.amsl.com>; Wed, 24 Dec 2014 17:37:10 -0800 (PST)
Received: from klaatu.metaparadigm.com (klaatu.metaparadigm.com [67.207.128.90]) (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 F3C521A6F67 for <tls@ietf.org>; Wed, 24 Dec 2014 17:37:09 -0800 (PST)
Received: from monty.local (unknown.maxonline.com.sg [58.182.90.50] (may be forged)) (authenticated bits=0) by klaatu.metaparadigm.com (8.14.4/8.14.4/Debian-4) with ESMTP id sBP1voMO012463 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Thu, 25 Dec 2014 01:57:53 GMT
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=metaparadigm.com; s=klaatu; t=1419472674; bh=RDTatSUd89Y4/BaFGDXvdUUS+mPJjH6GumrvBvwCw1I=; h=Date:From:To:Subject:References:In-Reply-To:From; b=XSZhuoAPOfo39vfqxLtMaKsKEwlmY04nqE0WarACRejkkV+4Bt4tYWX3V6vGiVJbi xYQJB9OLxg6jYr1VdEEktEvwa4dlDnMMFMbhXCMZpgqn5KTyu5WePfXqHiteV0eJQg rPMcT3pnO+IG9XO1mXDfn9ZVcUwmpRB0OYvg4w1s=
Message-ID: <549B6A26.7020801@metaparadigm.com>
Date: Thu, 25 Dec 2014 09:36:38 +0800
From: Michael Clark <michael@metaparadigm.com>
Organization: Metaparadigm Pte Ltd
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.3.0
MIME-Version: 1.0
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>, "<tls@ietf.org>" <tls@ietf.org>
References: <9A043F3CF02CD34C8E74AC1594475C73AAF49636@uxcn10-tdc05.UoA.auckland.ac.nz> <549B61E4.8080301@metaparadigm.com> <549B6998.6050405@metaparadigm.com>
In-Reply-To: <549B6998.6050405@metaparadigm.com>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: clamav-milter 0.98.4 at klaatu.metaparadigm.com
X-Virus-Status: Clean
Archived-At: http://mailarchive.ietf.org/arch/msg/tls/G-MjxRzV54QO3QY6AhnGU8JmQPk
Subject: Re: [TLS] AAED ciphers: AES-GCM vs AES-EAX/AES-CCM: a meta-analysis
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tls>, <mailto:tls-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/tls/>
List-Post: <mailto:tls@ietf.org>
List-Help: <mailto:tls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 25 Dec 2014 01:37:10 -0000

On 25/12/14 9:34 am, Michael Clark wrote:
> The other point being to remove MAC-then-encrypt from TLSv1.3, not
> necessarily AES-CBC (as its non parallelism is a good property in
> certain situations).
>
> The principle is considering TLSv1.3 from a 'profile' perspective and
> that the 'known problematic' MAC-then-encrypt could be supported by
> implementations that choose to offer TLSv1.2 (and older) profiles and
> drop encrypt-then-MAC and make MAC-then-encrypt mandatory in the TLSv1.3

correction:

drop MAC-then-encrypt and make encrypt-then-MAC mandatory in the TLSv1.3