From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E9990CB1 for ; Fri, 23 Sep 2016 16:18:34 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail148102.authsmtp.net (outmail148102.authsmtp.net [62.13.148.102]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 4326F23B for ; Fri, 23 Sep 2016 16:18:31 +0000 (UTC) Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt20.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u8NGILNf023759; Fri, 23 Sep 2016 17:18:21 +0100 (BST) Received: from petertodd.org (ec2-52-5-185-120.compute-1.amazonaws.com [52.5.185.120]) (authenticated bits=0) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u8NGIIYT045993 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 23 Sep 2016 17:18:19 +0100 (BST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 7E6654008D; Fri, 23 Sep 2016 16:14:32 +0000 (UTC) Received: by localhost (Postfix, from userid 1000) id 3A1F42051F; Fri, 23 Sep 2016 12:18:17 -0400 (EDT) Date: Fri, 23 Sep 2016 12:18:17 -0400 From: Peter Todd To: Luke Dashjr , Bitcoin Protocol Discussion Message-ID: <20160923161817.GA22926@fedora-21-dvm> References: <201609230957.03138.luke@dashjr.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="pWyiEgJYm5f9v55/" Content-Disposition: inline In-Reply-To: <201609230957.03138.luke@dashjr.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-Server-Quench: 57495eb1-81a9-11e6-829e-00151795d556 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdAEUC1AEAgsB AmAbWlNeUVV7WGo7 bghPaBtcak9QXgdq T0pMXVMcUQ0WdmV4 b3oeVhx7fgYIfXhz YQhnWXRSWREodFt1 Qx9dCGwHMGF9YGIW BV1YdwJRcQRDe0tA b1YxNiYHcQ5VPz4z GA41ejw8IwAXAgVt Cg0XJFwOEw4sJgkX Zz0pPh8LOmYmbhkT Aj0JCmJ0 X-Authentic-SMTP: 61633532353630.1037:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 52.5.185.120/25 X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: Re: [bitcoin-dev] BIP draft: OP_CHECKBLOCKATHEIGHT X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Sep 2016 16:18:35 -0000 --pWyiEgJYm5f9v55/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 23, 2016 at 09:57:01AM +0000, Luke Dashjr via bitcoin-dev wrote: > This BIP describes a new opcode (OP_CHECKBLOCKATHEIGHT) for the Bitcoin= =20 > scripting system to address reissuing bitcoin transactions when the coins= they=20 > spend have been conflicted/double-spent. >=20 > https://github.com/luke-jr/bips/blob/bip-cbah/bip-cbah.mediawiki >=20 > Does this seem like a good idea/approach? Your BIP is a bit confusing: you say "In some circumstances, users may wish= to spend received bitcoins before they have confirmed on the blockchain", but = what you're really referring to isn't spending unconfirmed outputs - which OP_CHECKBLOCKATHEIGHT can't protect - but rather spending outputs with a sm= all number of confirmations. In the existing ecosystem, if multi-block reorgs were a regular event Bitco= in would be in a lot of trouble; since they're rare, advising wallet authors to simply refuse to make transactions for some time after such a reorg may be a better solution. After all, a multi-block reorg is a strong indication that there's somehting very wrong with the network, and it'd be safer to stop us= ing Bitcoin for awhile until things settle down. --=20 https://petertodd.org 'peter'[:-1]@petertodd.org --pWyiEgJYm5f9v55/ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJX5VXGAAoJEGOZARBE6K+yngoH/2tMCMMyCztRuB78nHltFi2K D90atoFGpVPlOq7DpLJl3EhXyJdoun9QqWWAyIMCz/efD5EAJptcbeN+dcVzIwYG RvvBUqcZOTco319DHXv4OorAanVDzSutI7oM4sJ9P2ONyFSHPygEu3FCzybS5u6s Cvp42GQRP2dKSt3u52NjCD4rU1LJWmqFJ7kMYTUGX0WXA9DZNDBryMv5g8LRGm6c +QhOtKaVOGOhGub/52Gn7TCqoE5a2yJCsCxNT/fBAnnkuvHprElRgd+hMHEfHdlj N541UV8uE8ehwyjUII553al1WKx6fiNJD1riq7W4rwiS3puHR9ChFLmDIxV4jtc= =HOIj -----END PGP SIGNATURE----- --pWyiEgJYm5f9v55/--