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 28A288A1 for ; Tue, 16 Aug 2016 17:53:12 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from erelay3.ox.registrar-servers.com (erelay3.ox.registrar-servers.com [192.64.117.2]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 2001A20A for ; Tue, 16 Aug 2016 17:53:11 +0000 (UTC) Received: from localhost (unknown [127.0.0.1]) by erelay1.ox.registrar-servers.com (Postfix) with ESMTP id 9D5BC220A13C for ; Tue, 16 Aug 2016 17:53:10 +0000 (UTC) Received: from erelay1.ox.registrar-servers.com ([127.0.0.1]) by localhost (erelay.ox.registrar-servers.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id vc-h4jU2BU4F for ; Tue, 16 Aug 2016 13:53:09 -0400 (EDT) Received: from MTA-08.privateemail.com (unknown [10.20.150.180]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by erelay1.ox.registrar-servers.com (Postfix) with ESMTPS id 53AFB220A100 for ; Tue, 16 Aug 2016 13:53:09 -0400 (EDT) Received: from APP-06 (unknown [10.20.147.156]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by MTA-08.privateemail.com (Postfix) with ESMTPSA id C9F3B60032 for ; Tue, 16 Aug 2016 17:53:08 +0000 (UTC) Date: Tue, 16 Aug 2016 13:53:08 -0400 (EDT) From: Johnson Lau Reply-To: Johnson Lau To: bitcoin-dev@lists.linuxfoundation.org Message-ID: <1736097121.90204.1471369988809@privateemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Priority: 3 Importance: Medium X-Mailer: Open-Xchange Mailer v7.8.1-Rev18 X-Originating-Client: open-xchange-appsuite 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: [bitcoin-dev] New BIP: Dealing with OP_IF and OP_NOTIF malleability in P2WSH 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: Tue, 16 Aug 2016 17:53:12 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 A new BIP is prepared to deal with OP_IF and OP_NOTIF malleability in P2WSH: https://github.com/jl2012/bips/blob/minimalif/bip-minimalif.mediawiki https://github.com/bitcoin/bitcoin/pull/8526 BIP: x Title: Dealing with OP_IF and OP_NOTIF malleability in P2WSH Author: Johnson Lau Status: Draft Type: Standards Track Created: 2016-08-17 Abstract This document specifies proposed changes to the Bitcoin script validity rules in order to make transaction malleability related to OP_IF and OP_NOTIF impossible in pay-to-witness-script-hash (P2WSH) scripts. Motivation OP_IF and OP_NOTIF are flow control codes in the Bitcoin script system. The programme flow is decided by whether the top stake value is True or False. However, this behaviour opens a source of malleability as a third party may replace a True (False) stack item with any other True (False) value without invalidating the transaction. The proposed rules apply only to pay-to-witness-script-hash (P2WSH) scripts described in BIP141, which has not been activated on the Bitcoin mainnet as of writing. To ensure OP_IF and OP_NOTIF transactions created before the introduction of this BIP will still be accepted by the network, the new rules are not applied to non-segregated witness scripts. Specification In P2WSH, the argument for OP_IF and OP_NOTIF MUST be exactly an empty vector or 0x01, or the script evaluation fails immediately. This is deployed using BIP9 after segregated witness (BIP141) is activated. Details TBD. Compatibility This is a softfork on top of BIP141. The rules are enforced as a relay policy by the reference client since the first release of BIP141 (v0.13.1). To avoid risks of fund loss, users MUST NOT create P2WSH scripts that are incompatible with this BIP. An OP_0NOTEQUAL may be used before OP_IF or OP_NOTIF to imitate the original behaviour (which may also re-enable the malleability vector depending on the exact script). Implementation https://github.com/bitcoin/bitcoin/pull/8526 Copyright This work is placed in the public domain. -----BEGIN PGP SIGNATURE----- Comment: GPGTools - https://gpgtools.org iQGcBAEBCgAGBQJXs1LgAAoJEO6eVSA0viTSrJQL/A/womJKgi4FuyBTL9oykCss aBMNN9+SLtmuH7SBgEUGZ8TFxa2st+6RP6Imu+Vvn4O5sXQl3DIXV+X38X93sUYk wrjdpvdpqFFYJezPDESz6pR/6bZ1ES0aO2QqX578/8sqr8GO6L388s66vJeIGj4n 0LWW8sdEypMuV3HUG/9FFdUNHgiVX1U0sS1rT3P4aN30JYtb7PQpd7r8KTMta7Rt L1VOZB+W3m2m2YZ9gB7IRmMfzzNm2QXRTPIZXt2x3mYDBuMkp+zEd5+ogA4sBpgP wp2+l/aos686v0w8QYiNUX2+9Qpe7+238qUpw75d2XJYmLzdotWFvmp4g1hP+awX HEfwe4BUM+El17LjrHkNeMWNJXMlhTtXb2i0XMj8tU5lZVHep4WpQ+LEahrNlsUl FdFsi3q8HeWh8JsGaNCL41Bgbg/rKb5hUXyF6hTRHa//E6llOrpXRnsloKgBLv8c QezgKTAPwwgdjcS6Ek0AqgLp7bCFRijCduYH9i9uaQ== =lLIZ -----END PGP SIGNATURE-----