Re: [DNSOP] Whiskey Tango Foxtrot on key lengths...
Colm MacCárthaigh <colm@allcosts.net> Tue, 01 April 2014 15:15 UTC
Return-Path: <colm@allcosts.net>
X-Original-To: dnsop@ietfa.amsl.com
Delivered-To: dnsop@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 50F831A07DE for <dnsop@ietfa.amsl.com>; Tue, 1 Apr 2014 08:15:41 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.677
X-Spam-Level:
X-Spam-Status: No, score=-1.677 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FM_FORGED_GMAIL=0.622, HTML_MESSAGE=0.001, MIME_8BIT_HEADER=0.3, RCVD_IN_DNSWL_LOW=-0.7] 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 3dgmW4QrQjFG for <dnsop@ietfa.amsl.com>; Tue, 1 Apr 2014 08:15:40 -0700 (PDT)
Received: from mail-ob0-f181.google.com (mail-ob0-f181.google.com [209.85.214.181]) by ietfa.amsl.com (Postfix) with ESMTP id 05D8D1A07AB for <dnsop@ietf.org>; Tue, 1 Apr 2014 08:15:39 -0700 (PDT)
Received: by mail-ob0-f181.google.com with SMTP id wp4so11174345obc.40 for <dnsop@ietf.org>; Tue, 01 Apr 2014 08:15:36 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=tBhkiQMS3IJopsOweW2QxZWHJOG9rUWZ1YHyqdaUMGs=; b=cIlaHG6S18u2W5jJkbV+sx9JmgsiBBuMNexyLbnSNylbxyrYnp9qwQ9O4vZe0eSw2v tKLqvRtfwcdqEq+HRSCq4vQ4dXxcLRRaynpb4ZTgJ2BA3er0PMUj9XSBGO+Ae5JYsjXp Qruooz5GYCCgQ5YdwoTR5S5o/pi55LX5KEqH0iVSRvwl8fusjchtbqr9fdszBu4CvTbb ApKYC9O4l2Tmx/AQh+g9P8JfA7jbJ/1EZZwB+sthO4j+Y1NTMospke1OZhEWq4cCMuuO py7LAuhl7k/O0vzDAYpLQgNDxh9GRLGNDhX1mL1aOBeHFMMCi3soLw86z/kqyGiEAP71 LQCw==
X-Gm-Message-State: ALoCoQko1ylHyDnKLdR0e+DBRB2ROXBqKRF6wDwB07axeyghXvGVAZ398OZk5pLEetTq5QzZARrL
MIME-Version: 1.0
X-Received: by 10.182.124.66 with SMTP id mg2mr16018574obb.9.1396365336406; Tue, 01 Apr 2014 08:15:36 -0700 (PDT)
Received: by 10.76.20.164 with HTTP; Tue, 1 Apr 2014 08:15:36 -0700 (PDT)
In-Reply-To: <102C13BE-E45E-437A-A592-FA373FF5C8F0@ogud.com>
References: <0EA28BE8-E872-46BA-85FD-7333A1E13172@icsi.berkeley.edu> <53345C77.8040603@uni-due.de> <B7893984-2FAD-472D-9A4E-766A5C212132@pch.net> <102C13BE-E45E-437A-A592-FA373FF5C8F0@ogud.com>
Date: Tue, 01 Apr 2014 08:15:36 -0700
Message-ID: <CAAF6GDfGiB_GEVQ=igi4BeQsYBtQrqQ=uKZvAoJuSTLYL6PRyA@mail.gmail.com>
From: Colm MacCárthaigh <colm@allcosts.net>
To: Olafur Gudmundsson <ogud@ogud.com>
Content-Type: multipart/alternative; boundary="f46d0444ed6ddaa69104f5fca343"
Archived-At: http://mailarchive.ietf.org/arch/msg/dnsop/NNYbEAcbsSlOdRoq3GwUp4nB22g
Cc: dnsop@ietf.org, Matthäus Wander <matthaeus.wander@uni-due.de>, Bill Woodcock <woody@pch.net>
Subject: Re: [DNSOP] Whiskey Tango Foxtrot on key lengths...
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: IETF DNSOP WG mailing list <dnsop.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dnsop>, <mailto:dnsop-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/dnsop/>
List-Post: <mailto:dnsop@ietf.org>
List-Help: <mailto:dnsop-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dnsop>, <mailto:dnsop-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 01 Apr 2014 15:15:41 -0000
On Tue, Apr 1, 2014 at 5:39 AM, Olafur Gudmundsson <ogud@ogud.com> wrote: > Doing these big jumps is the wrong thing to do, increasing the key size > increases three things: > time to generate signatures > bits on the wire > verification time. > > I care more about verification time than bits on the wire (as I think that > is a red herring). > Signing time increase is a self inflicted wound so that is immaterial. > > sign verify sign/s verify/s > rsa 1024 bits 0.000256s 0.000016s 3902.8 62233.2 > rsa 2048 bits 0.001722s 0.000053s 580.7 18852.8 > rsa 4096 bits 0.012506s 0.000199s 80.0 5016.8 > > Thus doubling the key size decreases the verification performance by > roughly by about 70%. > With those numbers; if the validating resolver uses speculative/optimistic concurrency [1] then jumping from 1024 to 4096 bits, the user-impact is that ~180us are added to the overall resolution time. Zero in the cached case. There is an impact on the overall capacity of the resolver, though it's a function of cache-miss-rate (since cache hits need not be verified). Large centralised resolver operators may face some pressure (anyone doing validation locally is unlikely to notice), but is it sensible to compromise your zone security to accommodate that? [1] There's no need to wait for a response to be validated before recursing, a validating resolver can first recurse and later backtrack if the parent signature doesn't verify. -- Colm
- [DNSOP] Whiskey Tango Foxtrot on key lengths... Nicholas Weaver
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Nicholas Weaver
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Joe Abley
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Paul Hoffman
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Nicholas Weaver
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Rose, Scott
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Stephane Bortzmeyer
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Matthäus Wander
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Christopher Morrow
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Nicholas Weaver
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Christopher Morrow
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Paul Wouters
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Paul Wouters
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Joe Abley
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Joe Abley
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Bill Woodcock
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Tony Finch
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Colm MacCárthaigh
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Andrew Sullivan
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Tony Finch
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Joe Abley
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Thierry Moreau
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Matthäus Wander
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Joe Abley
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Colm MacCárthaigh
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… S Moonesamy
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Olafur Gudmundsson
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Bill Woodcock
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Nicholas Weaver
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Nicholas Weaver
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Jelte Jansen
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Mark Andrews
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Colm MacCárthaigh
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Mark Andrews
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Colm MacCárthaigh
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Olafur Gudmundsson
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Olafur Gudmundsson
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Paul Hoffman
- [DNSOP] CD (Re: Whiskey Tango Foxtrot on key leng… Evan Hunt
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Mark Andrews
- [DNSOP] CD bit (was Re: Whiskey Tango Foxtrot on … Andrew Sullivan
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Olafur Gudmundsson
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Colm MacCárthaigh
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Paul Wouters
- Re: [DNSOP] CD bit (was Re: Whiskey Tango Foxtrot… Mark Andrews
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Nicholas Weaver
- Re: [DNSOP] CD bit (was Re: Whiskey Tango Foxtrot… Andrew Sullivan
- Re: [DNSOP] CD (Re: Whiskey Tango Foxtrot on key … Colm MacCárthaigh
- Re: [DNSOP] CD (Re: Whiskey Tango Foxtrot on key … Nicholas Weaver
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Phillip Hallam-Baker
- [DNSOP] Current DNSOP thread and why 1024 bits Edward Lewis
- Re: [DNSOP] Current DNSOP thread and why 1024 bits Nicholas Weaver
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Stephane Bortzmeyer
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Paul Hoffman
- Re: [DNSOP] Current DNSOP thread and why 1024 bits Paul Hoffman
- [DNSOP] mailing list behavior Re: Current DNSOP t… Suzanne Woolf
- Re: [DNSOP] Current DNSOP thread and why 1024 bits Colm MacCárthaigh
- Re: [DNSOP] Current DNSOP thread and why 1024 bits Paul Wouters
- Re: [DNSOP] Current DNSOP thread and why 1024 bits S Moonesamy
- Re: [DNSOP] Current DNSOP thread and why 1024 bits Paul Hoffman
- Re: [DNSOP] Current DNSOP thread and why 1024 bits Rose, Scott
- Re: [DNSOP] CD (Re: Whiskey Tango Foxtrot on key … Mark Andrews
- Re: [DNSOP] CD (Re: Whiskey Tango Foxtrot on key … Colm MacCárthaigh
- Re: [DNSOP] Current DNSOP thread and why 1024 bits S Moonesamy
- Re: [DNSOP] Current DNSOP thread and why 1024 bits David Conrad
- Re: [DNSOP] Current DNSOP thread and why 1024 bits Paul Wouters
- Re: [DNSOP] Current DNSOP thread and why 1024 bits Ben Laurie
- Re: [DNSOP] Whiskey Tango Foxtrot on key lengths.… Francis Dupont