Re: [Cfrg] erratum for hmac what do we think...

"Salz, Rich" <rsalz@akamai.com> Thu, 02 February 2017 15:21 UTC

Return-Path: <rsalz@akamai.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 BBFF0129663 for <cfrg@ietfa.amsl.com>; Thu, 2 Feb 2017 07:21:38 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.9
X-Spam-Level:
X-Spam-Status: No, score=-5.9 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_LOW=-0.7, RP_MATCHES_RCVD=-3.199, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=akamai.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 iDiAljldIHPY for <cfrg@ietfa.amsl.com>; Thu, 2 Feb 2017 07:21:37 -0800 (PST)
Received: from prod-mail-xrelay05.akamai.com (prod-mail-xrelay05.akamai.com [23.79.238.179]) by ietfa.amsl.com (Postfix) with ESMTP id A18AE129662 for <Cfrg@irtf.org>; Thu, 2 Feb 2017 07:21:37 -0800 (PST)
Received: from prod-mail-xrelay05.akamai.com (localhost.localdomain [127.0.0.1]) by postfix.imss70 (Postfix) with ESMTP id A74CF4334AC; Thu, 2 Feb 2017 15:21:36 +0000 (GMT)
Received: from prod-mail-relay11.akamai.com (prod-mail-relay11.akamai.com [172.27.118.250]) by prod-mail-xrelay05.akamai.com (Postfix) with ESMTP id 90E9B43341C; Thu, 2 Feb 2017 15:21:36 +0000 (GMT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=akamai.com; s=a1; t=1486048896; bh=G+fRMHMA7umeYVS6NnuEB7nxDuZeHKoeVH4gxYlOgXk=; l=324; h=From:To:Date:References:In-Reply-To:From; b=wj8A0Wv8xrDLQcOlBHkZunUWnu169mgr+ZMgFyZO9zGs2DymrPCmVYD0OlR50fM7V 76JwLlYjsTxghgHc2bNcVvZpFWGOs2TLaZLYWQNPyMD7pVx3WuflaL2NEGRegsClY8 og+ZAi86eME0ik3+eDhdiiGoV4QaR/K4i1HDkvDs=
Received: from email.msg.corp.akamai.com (usma1ex-cas1.msg.corp.akamai.com [172.27.123.30]) by prod-mail-relay11.akamai.com (Postfix) with ESMTP id 8D75D1FC88; Thu, 2 Feb 2017 15:21:36 +0000 (GMT)
Received: from USMA1EX-DAG1MB3.msg.corp.akamai.com (172.27.123.103) by usma1ex-dag1mb4.msg.corp.akamai.com (172.27.123.104) with Microsoft SMTP Server (TLS) id 15.0.1178.4; Thu, 2 Feb 2017 10:21:36 -0500
Received: from USMA1EX-DAG1MB3.msg.corp.akamai.com ([172.27.123.103]) by usma1ex-dag1mb3.msg.corp.akamai.com ([172.27.123.103]) with mapi id 15.00.1178.000; Thu, 2 Feb 2017 10:21:36 -0500
From: "Salz, Rich" <rsalz@akamai.com>
To: "Paterson, Kenny" <Kenny.Paterson@rhul.ac.uk>, Stephen Farrell <stephen.farrell@cs.tcd.ie>, "cfrg@irtf.org" <Cfrg@irtf.org>
Thread-Topic: [Cfrg] erratum for hmac what do we think...
Thread-Index: AQHSfQSjLR5A9wxQCUyU4vgAZUrraqFWFUCA///AcnA=
Date: Thu, 2 Feb 2017 15:21:35 +0000
Message-ID: <f4d4f7170d5849e9a2fc532160bff698@usma1ex-dag1mb3.msg.corp.akamai.com>
References: <666efaf7-b660-e20b-8a8a-8949a64e9bed@cs.tcd.ie> <D4B8ED5B.83EFC%kenny.paterson@rhul.ac.uk>
In-Reply-To: <D4B8ED5B.83EFC%kenny.paterson@rhul.ac.uk>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [172.19.46.204]
Content-Type: text/plain; charset="Windows-1252"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: <https://mailarchive.ietf.org/arch/msg/cfrg/XF3M-o0H5-vOd9b4eFEuf-GLXyk>
Subject: Re: [Cfrg] erratum for hmac what do we think...
X-BeenThere: cfrg@irtf.org
X-Mailman-Version: 2.1.17
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: Thu, 02 Feb 2017 15:21:39 -0000

> I looked quickly myself. It's an undesirable property, but I don't think it's
> disastrous

If this is accurate (paging Hugo... :) then I think the best reply to this is a couple of sentences in the security considerations advising applications that are concerned to limit keys to B bytes instead of hashing.