From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Xa6zz-0005l8-UF for bitcoin-development@lists.sourceforge.net; Fri, 03 Oct 2014 17:50:35 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of dashjr.org designates 192.3.11.21 as permitted sender) client-ip=192.3.11.21; envelope-from=luke@dashjr.org; helo=zinan.dashjr.org; Received: from zinan.dashjr.org ([192.3.11.21]) by sog-mx-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1Xa6zz-0001Ui-2t for bitcoin-development@lists.sourceforge.net; Fri, 03 Oct 2014 17:50:35 +0000 Received: from ishibashi.localnet (unknown [IPv6:2001:470:5:265:be5f:f4ff:febf:4f76]) (Authenticated sender: luke-jr) by zinan.dashjr.org (Postfix) with ESMTPSA id 578BF1083681; Fri, 3 Oct 2014 17:50:29 +0000 (UTC) From: Luke Dashjr To: bitcoin-development@lists.sourceforge.net Date: Fri, 3 Oct 2014 17:50:26 +0000 User-Agent: KMail/1.13.7 (Linux/3.15.5-gentoo; KDE/4.12.5; x86_64; ; ) References: <20141001130826.GM28710@savin.petertodd.org> <1987325.zKPNeYyO8K@crushinator> In-Reply-To: <1987325.zKPNeYyO8K@crushinator> X-PGP-Key-Fingerprint: E463 A93F 5F31 17EE DE6C 7316 BD02 9424 21F4 889F X-PGP-Key-ID: BD02942421F4889F X-PGP-Keyserver: hkp://pgp.mit.edu MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201410031750.27323.luke@dashjr.org> X-Spam-Score: -1.5 (-) 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 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record X-Headers-End: 1Xa6zz-0001Ui-2t Cc: Flavien Charlon Subject: Re: [Bitcoin-development] [BIP draft] CHECKLOCKTIMEVERIFY - Prevent a txout from being spent until an expiration time 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: Fri, 03 Oct 2014 17:50:36 -0000 On Friday, October 03, 2014 2:28:17 PM Matt Whitlock wrote: > Is there a reason why we can't have the new opcode simply replace the top > stack item with the block height of the txout being redeemed? Then > arbitrary logic could be implemented, including "output cannot be spent > until a certain time" and also "output can ONLY be spent until a certain > time," as well as complex logic with alternative key groups with differing > time constraints. This cannot be done in a softfork. Furthermore, "output can ONLY be spent until a certain time" contradict's Bitcoin's present security assumptions: that assuming a honest sender, the transaction will remain valid and simply re-confirm if a reorg kicks it out. Luke