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 C5144BA6 for ; Fri, 3 Jul 2015 21:57:10 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail148113.authsmtp.com (outmail148113.authsmtp.com [62.13.148.113]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id F3F91E9 for ; Fri, 3 Jul 2015 21:57:09 +0000 (UTC) Received: from mail-c235.authsmtp.com (mail-c235.authsmtp.com [62.13.128.235]) by punt17.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t63Lv6cv086386; Fri, 3 Jul 2015 22:57:06 +0100 (BST) Received: from muck (us2x.mullvad.net [173.254.196.27]) (authenticated bits=128) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t63LuxoE072794 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Fri, 3 Jul 2015 22:57:03 +0100 (BST) Date: Fri, 3 Jul 2015 17:56:58 -0400 From: Peter Todd To: Mark Friedenbach Message-ID: <20150703215658.GC5916@muck> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="NKoe5XOeduwbEQHU" Content-Disposition: inline In-Reply-To: X-Server-Quench: 718cdf21-21ce-11e5-b397-002590a15da7 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aQdMdgEUEkAYAgsB AmMbWVZeVVp7WWY7 ag1ScwdYZlRPVgN0 Uk9WR1pVCwQmRRoC eltWDWxycAdBcXo+ ZERlV3IVW0VyJhIr QE9JF2xVMHphaTUa TRJbfgRJcANIexZF O1F6ACIKLwdSbGoL FQ4vNDcwO3BTJTpg CjsgFBo4YH5DVXZ7 DzwDBj4yBlZNAm0I MBErMhYdGk0WN0Q0 PhM8X1kfNRETEAhT EyMFHDVQIUIITDYq CgVBFVEfDD0VSG9W BQAuPg4OajYI X-Authentic-SMTP: 61633532353630.1023:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 173.254.196.27/587 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 Cc: bitcoin-dev@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] REQ BIP # / Discuss - Sweep incoming unconfirmed transactions with a bounty. X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Jul 2015 21:57:10 -0000 --NKoe5XOeduwbEQHU Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jul 01, 2015 at 09:52:57PM -0700, Mark Friedenbach wrote: > This is called child pays for parent and there is a three year old pull > request implementing it: >=20 > https://github.com/bitcoin/bitcoin/pull/1647 CPFP probably needs changes to the P2P layer to be able to support RBF scorched earth well unfortunately, as currently transactions are processed individually and out of context. In the RBF case you'd need to keep previously removed transactions in a buffer and evaluate new transactions against that buffer - relatively complex. The other big issue is that existing wallets don't appear to be very good at preventing double-spends. There's lots of edge cases where transations aren't recorded correctly, like crashes, shutting down unexpected etc. and in those cases there's a high chance of the wallet sending a double-spend by accident. There's also coinjoin to consider - plainly incompatible. With scorched-earth this will lead to losses. Fortunately you can implement scorched-earth using SIGHASH_ANYONECANPAY instead on an opt-in basis, which wallets could add only if they've taken the special engineering considerations into account first: "Replace-by-fee scorched-earth without child-pays-for-parent", Peter Todd, Bitcoin-development mailing list, Apr 28th 2014 http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2014-April/00562= 0.html For the OP: I'd be interested in pursuing this further. --=20 'peter'[:-1]@petertodd.org 000000000000000015665ce75a321e5827cdf9af667eaa75aaeefbc315514da5 --NKoe5XOeduwbEQHU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQGrBAEBCACVBQJVlwUnXhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw MDAwMDAwMDAwMDAwMDAxNTY2NWNlNzVhMzIxZTU4MjdjZGY5YWY2NjdlYWE3NWFh ZWVmYmMzMTU1MTRkYTUvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 ZUBwZXRlcnRvZC5vcmcACgkQwIXyHOf0udzz/gf/b9ZN4d969NJzzMsaDKlForCl dWq9AYJWDkTBNrwISclMD+kmvKdQ5w+NZpwyKT3how2UC4tgbUE94Sy5TyU838ve N48uTQzJNTxBrWmHJu5pXkUE+y6O6h6AJzSJTZHDqNMuqC26X7XabXPr0VGgb0xS dH27M18bJ3vFdZOYMfrsLpB20yJbh0+hpv5Z0VaMZE2JHuY8ZLE6oKF0qQE1pXW7 EhMMdN4FPJ+AEd1qicrTJTRW+x3khkhEtXLKP3uZRvLbkKHCFn/gyeIWwInqKYYj BTssiEpU3BwFQVnbVVRVXoTNd563FJkPNUSb6AseIwKllnwItODPPkRBoLywHQ== =D1c1 -----END PGP SIGNATURE----- --NKoe5XOeduwbEQHU--