Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192]
	helo=mx.sourceforge.net)
	by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76)
	(envelope-from <mark@monetize.io>) id 1XF50d-0000Gz-MQ
	for bitcoin-development@lists.sourceforge.net;
	Wed, 06 Aug 2014 17:28:19 +0000
Received: from mail-pa0-f47.google.com ([209.85.220.47])
	by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128)
	(Exim 4.76) id 1XF50c-0008Er-Uc
	for bitcoin-development@lists.sourceforge.net;
	Wed, 06 Aug 2014 17:28:19 +0000
Received: by mail-pa0-f47.google.com with SMTP id kx10so3796785pab.20
	for <bitcoin-development@lists.sourceforge.net>;
	Wed, 06 Aug 2014 10:28:13 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
	d=1e100.net; s=20130820;
	h=x-gm-message-state:message-id:date:from:organization:user-agent
	:mime-version:to:subject:references:in-reply-to:content-type
	:content-transfer-encoding;
	bh=5G+rFYv+vXdtuS9jsteIW23K9/pI9prNWOcaFw+9Fkc=;
	b=OJ5BMPF/49hgaaMqQ6IgGnShONM2Ox+VROq7ls8nQ4pnGihDpQDuv73S9t9cvCZhRq
	llBUwT04NkMMkOawKt1tceUKxiyiuvZVtBIn3wjMCpcNhAz5/rLovBxdC4S754bNt5jD
	OYxL+JyH357URfE5qg6ql7bXgZ49cZ3VyGq+cgThHUzpX5KafYfjmlsIkELnGY3MBaY9
	TJUZLgZeyLPvfMa09qZopQzmjhTol2V86j3niKSvMdSrob8rkMYcCs0z67fqy2tDfUfN
	thme1+763zUP0rb3WQJgPlCXwMDRKuFDe3xf1DNupxpFqWKVdEvS+1cK7XUprH6jTVLD
	7sqA==
X-Gm-Message-State: ALoCoQniXCJkZxUEJLQCTBdO1lZN6aY0JoxvtgBItJy7gW+jCujQEC9nFag61osvB5XUT4/u/7ZQ
X-Received: by 10.66.182.69 with SMTP id ec5mr12468370pac.125.1407345727401;
	Wed, 06 Aug 2014 10:22:07 -0700 (PDT)
Received: from [192.168.127.194] (173-228-106-61.dsl.dynamic.sonic.net.
	[173.228.106.61])
	by mx.google.com with ESMTPSA id f16sm2604595pdm.43.2014.08.06.10.22.03
	for <multiple recipients>
	(version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
	Wed, 06 Aug 2014 10:22:06 -0700 (PDT)
Message-ID: <53E26434.2070502@monetize.io>
Date: Wed, 06 Aug 2014 13:21:56 -0400
From: Mark Friedenbach <mark@monetize.io>
Organization: Monetize.io Inc.
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
	rv:31.0) Gecko/20100101 Thunderbird/31.0
MIME-Version: 1.0
To: Tom Harding <tomh@thinlink.com>, 
	Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
References: <CA+iPb=HkxeVPF0SynxCPgUkq4msrdfayFrVNFjzg29rFwqXv1w@mail.gmail.com>	<CAJHLa0O2wFq2Vs5Bes_8x1q_j0VC+U4DQkx=6GqT8w5e8Lh5Qg@mail.gmail.com>	<CA+iPb=ET+A-qB8TgPX8D-ut1DWnq9tZJ=14igfRVWO6eog6Xgw@mail.gmail.com>	<53E1A8AF.4030206@thinlink.com>	<CAJHLa0MfRhCPX8H92qc1kSebc=WrUzmSgbG331t4-zDHhTNu4w@mail.gmail.com>	<CANEZrP3eEiLxYfsAURRm4ysfS4TRgXxa_THxJ43cVH1OyR95JQ@mail.gmail.com>	<53E23F49.3020605@thinlink.com>	<CAJHLa0OtPA3DGQuJhp3zkK5dnBux6TFAw3qDsBdO0zaxrqBgRg@mail.gmail.com>	<CALxbBHXh-Fktsr96PMXdohJdgcUKoNreJ-ZuApKOX3-qSkdk2w@mail.gmail.com>	<63a80796-609e-43f5-9280-4cd8cf5d2648@email.android.com>	<CAJHLa0OQJEvQht_chF1gVG_BOwp=DW0zOOo3VE_acZonsSguWw@mail.gmail.com>
	<53E25F8A.5070905@thinlink.com>
In-Reply-To: <53E25F8A.5070905@thinlink.com>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
X-Spam-Score: 0.0 (/)
X-Spam-Report: Spam Filtering performed by mx.sourceforge.net.
	See http://spamassassin.org/tag/ for more details.
X-Headers-End: 1XF50c-0008Er-Uc
Subject: Re: [Bitcoin-development] deterministic transaction expiration
X-BeenThere: bitcoin-development@lists.sourceforge.net
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: <bitcoin-development.lists.sourceforge.net>
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
	<mailto:bitcoin-development-request@lists.sourceforge.net?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=bitcoin-development>
List-Post: <mailto:bitcoin-development@lists.sourceforge.net>
List-Help: <mailto:bitcoin-development-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
	<mailto:bitcoin-development-request@lists.sourceforge.net?subject=subscribe>
X-List-Received-Date: Wed, 06 Aug 2014 17:28:19 -0000

On 08/06/2014 01:02 PM, Tom Harding wrote:
> With first-eligible-height and last-eligible-height, creator could
> choose a lifetime shorter than the max,  and in addition, lock the whole
> thing until some point in the future.

Note that this would be a massive, *massive* change that would
completely break bitcoin output frangibility. Merchants would have to
start demanding input history back to a certain depth in order to ensure
they are not exposing themselves to undue reorg-expiry risk.

There are useful applications of a consensus-enforced expiry,
particularly within a private (signed block) side chain, and for that
reason it is useful to have a discussion about the merits of an nExpiry
field or BLOCK_HEIGHT / BLOCK_TIME opcode, and methods for achieving
either. However I don't see this ever becoming part of the public
bitcoin network.