Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XF2ps-0001NR-3x for bitcoin-development@lists.sourceforge.net; Wed, 06 Aug 2014 15:09:04 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of bitpay.com designates 209.85.213.171 as permitted sender) client-ip=209.85.213.171; envelope-from=jgarzik@bitpay.com; helo=mail-ig0-f171.google.com; Received: from mail-ig0-f171.google.com ([209.85.213.171]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XF2pq-0002SB-3c for bitcoin-development@lists.sourceforge.net; Wed, 06 Aug 2014 15:09:04 +0000 Received: by mail-ig0-f171.google.com with SMTP id l13so8822899iga.10 for ; Wed, 06 Aug 2014 08:08:56 -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:from:date :message-id:subject:to:cc:content-type; bh=0g4MTjaAtsQDSlMdXEGsBiW6xXhe/YqwN+d2miz/U6k=; b=k8EfdijW1PhUnE7UdYkeM8p4hv890V4dTPDGcshGGSpae0CQKZADx4p0tWjaTgbWxg XwNPENsFxwmVybp35sBG/l5fpW0uIqyGIoZPUYMjQbS80uBG8vUBDKM/tO57z3GGTH3M SbNziSWEK3uv9NOYhXGtLw3zL7WXB59onyjzB1z5aOrEFerub59BOnm4067QrreRV3Ky nR74C911GTet/1ZbgE0HHDkJHJYGa9bLv58eTCsUAXfYLzdrIkd784tTu/2nqNrsic9z It9/FikWWix1+B4ro/kgjgvFCekYzpZSBFWohEQO1gDQ7GR132JOl+uwafBnhjOg8hN0 Lc9Q== X-Gm-Message-State: ALoCoQn+THv6g8h0beFpCnYXTCre1VdMqEdDLNiwaGkYXdi4h4Dr6r1ivfOPwNurUrX8us3RJ1lz X-Received: by 10.50.80.116 with SMTP id q20mr60608690igx.22.1407337736286; Wed, 06 Aug 2014 08:08:56 -0700 (PDT) MIME-Version: 1.0 Received: by 10.107.10.78 with HTTP; Wed, 6 Aug 2014 08:08:36 -0700 (PDT) In-Reply-To: <53E23F49.3020605@thinlink.com> References: <53E1A8AF.4030206@thinlink.com> <53E23F49.3020605@thinlink.com> From: Jeff Garzik Date: Wed, 6 Aug 2014 11:08:36 -0400 Message-ID: To: Tom Harding Content-Type: multipart/alternative; boundary=089e01536682db5fce04fff759c0 X-Spam-Score: -0.6 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1XF2pq-0002SB-3c Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] deterministic transaction expiration X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Aug 2014 15:09:04 -0000 --089e01536682db5fce04fff759c0 Content-Type: text/plain; charset=UTF-8 ...because nLockTime is the exact opposite of expiration. A locked TX begins life invalid, and becomes valid (not-expired) after nLockTime passes. A new field containing expiration time would work. On Wed, Aug 6, 2014 at 10:44 AM, Tom Harding wrote: > > How is eventual expiration of a tx that started life with an nLockTime in > the future "breaking", any more than any other tx expiring? > > > > On 8/6/2014 6:54 AM, Mike Hearn wrote: > > We could however introduce a new field in a new tx version. We know we > need to rev the format at some point anyway. > > > On Wed, Aug 6, 2014 at 2:55 PM, Jeff Garzik wrote: > >> ...and existing users and uses of nLockTime suddenly become worthless, >> breaking payment channel refunds and other active uses of nLockTime. >> >> You cannot assume the user is around to rewrite their nLockTime, if it >> fails to be confirmed before some arbitrary deadline being set. >> >> >> >> On Wed, Aug 6, 2014 at 12:01 AM, Tom Harding wrote: >> >>> ... >>> >> > If nLockTime is used for expiration, transaction creator can't lie to >>> help tx live longer without pushing initial confirmation eligibility >>> into the future. Very pretty. It would also enable "fill or kill" >>> transactions with a backdated nLockTime, which must be confirmed in a >>> few blocks, or start vanishing from mempools. >>> >> > -- Jeff Garzik Bitcoin core developer and open source evangelist BitPay, Inc. https://bitpay.com/ --089e01536682db5fce04fff759c0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
=C2=A0...because nLockTime is the exact opposite of e= xpiration.=C2=A0 A locked TX begins life invalid, and becomes valid (not-ex= pired) after nLockTime passes.

A new field containing expirati= on time would work.



On = Wed, Aug 6, 2014 at 10:44 AM, Tom Harding <tomh@thinlink.com> wrote:
=20 =20 =20

How is eventual expiration of a tx that started life with an nLockTime in the future "breaking", any more than any other t= x expiring?



On 8/6/2014 6:54 AM, Mike Hearn wrote:
We could however introduce a new field in a new tx version. We know we need to rev the format at some point anyway.


On Wed, Aug 6, 2014 at 2= :55 PM, Jeff Garzik <jgarzik@bitpay.com> wrote:
=C2=A0...and existing users and uses of nLockT= ime suddenly become worthless, breaking payment channel refunds and other active uses of nLockTime.

You cannot assume the user is around to rewrite their nLockTime, if it fails to be confirmed before some arbitrary deadline being set.



On Wed, Aug 6,= 2014 at 12:01 AM, Tom Harding <tomh@thinlink.com> wrote:
...

If nLockTime is used for expiration, transaction creator can't lie to
help tx live longer without pushing initial confirmation eligibility
into the future. =C2=A0Very pretty. =C2=A0It would al= so enable "fill or kill"
transactions with a backdated nLockTime, which must be confirmed in a
few blocks, or start vanishing from mempools.




--
Jeff Garzik
Bitcoin = core developer and open source evangelist
BitPay, Inc. =C2=A0 =C2=A0 =C2= =A0https://bitpay.com/
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