Re: Predictable Internet Time

Nico Williams <nico@cryptonector.com> Fri, 21 April 2017 17:26 UTC

Return-Path: <nico@cryptonector.com>
X-Original-To: ietf@ietfa.amsl.com
Delivered-To: ietf@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C330D12957A for <ietf@ietfa.amsl.com>; Fri, 21 Apr 2017 10:26:33 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.799
X-Spam-Level:
X-Spam-Status: No, score=-4.799 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_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-2.8, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cryptonector.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 se1AgQuaCjMo for <ietf@ietfa.amsl.com>; Fri, 21 Apr 2017 10:26:32 -0700 (PDT)
Received: from homiemail-a72.g.dreamhost.com (sub4.mail.dreamhost.com [69.163.253.135]) (using TLSv1.1 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 7E0071294A3 for <ietf@ietf.org>; Fri, 21 Apr 2017 10:26:32 -0700 (PDT)
Received: from homiemail-a72.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a72.g.dreamhost.com (Postfix) with ESMTP id AC329A00CEC1; Fri, 21 Apr 2017 10:26:31 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=cryptonector.com; h=date :from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=cryptonector.com; bh=LDk0x/5S0Gbv4t m/7GwSok+6/UE=; b=fczKDuEzfNjI1iG/NhE4TNKyqm4DkfAeRD3eVLeXXwhmHi E2p5aBLjzOBax2qnsHOGRB0oWe3FVly42sMYiB2iGyD7P43Yb5O8QM/mnOSIVnGs BtX8Hmp/yxRwaZdPXQCUmkqNBusTKPRvnuSyO7OkiudZ6x9VGHv5bdIv3Kp7Q=
Received: from localhost (cpe-70-123-158-140.austin.res.rr.com [70.123.158.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: nico@cryptonector.com) by homiemail-a72.g.dreamhost.com (Postfix) with ESMTPSA id 3CC7DA000B32; Fri, 21 Apr 2017 10:26:31 -0700 (PDT)
Date: Fri, 21 Apr 2017 12:26:27 -0500
From: Nico Williams <nico@cryptonector.com>
To: Phillip Hallam-Baker <phill@hallambaker.com>
Cc: Paul Eggert <eggert@cs.ucla.edu>, IETF Discussion Mailing List <ietf@ietf.org>, Patrik Fältström <paf@frobbit.se>
Subject: Re: Predictable Internet Time
Message-ID: <20170421172626.GG2856@localhost>
References: <CAMm+Lwi_jU6gjdtdM6a2n_9_89tUvWBNXxnMtSjTEA++h1D4Ew@mail.gmail.com> <e0a43370-751f-808c-3719-9716f9cd57d1@isi.edu> <B990A5A4-D62B-4E10-9FF7-7BA4377C0958@frobbit.se> <7bc1a350-549c-c649-81c6-bcd19cff36d7@cisco.com> <B2E6846E-F25B-4792-8E13-B5D898B67223@frobbit.se> <9f719b6a-f3c0-ef98-1636-86e84106e366@cisco.com> <16db07fe-acc5-d178-b56c-755c3cf70680@cs.ucla.edu> <CAMm+LwjQ_kaSBzcJhem5CbPLvMCAJRFnRpqJgu8SFTTQpt4bzQ@mail.gmail.com> <20170418222004.GB2856@localhost> <CAMm+LwgRegXgM3TqRJW_jfv+S6GrJ5RqJkpfaX0xQ0M7ZO_gPA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <CAMm+LwgRegXgM3TqRJW_jfv+S6GrJ5RqJkpfaX0xQ0M7ZO_gPA@mail.gmail.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf/Qjoddn9RHEMOUQIQRc_LaK8Vd-4>
X-BeenThere: ietf@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: IETF-Discussion <ietf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf>, <mailto:ietf-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ietf/>
List-Post: <mailto:ietf@ietf.org>
List-Help: <mailto:ietf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf>, <mailto:ietf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 21 Apr 2017 17:26:34 -0000

On Fri, Apr 21, 2017 at 12:32:11PM -0400, Phillip Hallam-Baker wrote:
> On Tue, Apr 18, 2017 at 6:20 PM, Nico Williams <nico@cryptonector.com>
> wrote:
> > On Tue, Jan 03, 2017 at 05:34:11PM -0500, Phillip Hallam-Baker wrote:
> > > As I said, I want 30-100 years lead time so I can bake the schedule into
> > > devices and remove a trust dependency.
> >
> > 30 years' lead time for leap seconds?  Can't be done.
> >
> > Leap seconds depend on events such as earthquakes.
> >
> > You can estimate their frequency, but you can't estimate when they'll be
> > inserted.
> >
> 
> Of course it can be done. I can show you one very simple algorithm that
> allows every leap second to the end of time to be known right now:
> 
> "All leap seconds are abolished. UTC = TAI +37 for all future dates."

That's moving the goal posts, and it's not your smeared time proposal.

Good, because smeared time is a terrible idea.  We don't need more time
standards to convert between.  Smearing time does not make UTC go away,
nor conversions to/from UTC.  Systems will always need to know about
leap seconds in order to convert to/from UTC because there will always
be parts of the system (or apps) that need TAI or something close to
TAI.  Smearing does not make that go away -- it solves nothing.

"Internet time" (that which we use in [new] Internet protocols) should
just be TAI.  And every existing Internet protocol should be updated to
indicate which time is used in practice, UTC or TAI, regardless of what
was originally specified.

Nico
--