Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 0181B94E for ; Wed, 8 Jun 2016 07:29:41 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from zinan.dashjr.org (zinan.dashjr.org [192.3.11.21]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id A9F34142 for ; Wed, 8 Jun 2016 07:29:40 +0000 (UTC) Received: from ishibashi.localnet (unknown [IPv6:2001:470:5:265:61b6:56a6:b03d:28d6]) (Authenticated sender: luke-jr) by zinan.dashjr.org (Postfix) with ESMTPSA id 002FF38A17C6; Wed, 8 Jun 2016 07:29:29 +0000 (UTC) X-Hashcash: 1:25:160608:bitcoin-dev@lists.linuxfoundation.org::glDY8JRHucM5E4cT:17km X-Hashcash: 1:25:160608:jl2012@xbt.hk::Mcu0rXM9gQexzNl0:P4P9 From: Luke Dashjr To: bitcoin-dev@lists.linuxfoundation.org, Johnson Lau Date: Wed, 8 Jun 2016 07:29:22 +0000 User-Agent: KMail/1.13.7 (Linux/4.1.18-gentoo; KDE/4.14.16; x86_64; ; ) References: In-Reply-To: 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-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201606080729.24789.luke@dashjr.org> X-Spam-Status: No, score=-3.3 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD 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] BIP141 segwit consensus rule update: extension of witness program definition 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: Wed, 08 Jun 2016 07:29:41 -0000 On Wednesday, June 08, 2016 5:57:36 AM Johnson Lau via bitcoin-dev wrote: > Why not make it even bigger, e.g. 75 bytes? I don't see a sufficient answer to this question. Pieter explained why >75 would be annoying, but 75 seems like it should be fine. > In any case, since scripts with a 1-byte push followed by a push of >40 > bytes remain anyone-can-spend, we always have the option to redefine them > with a softfork. It's not that simple, since this is preventing use of the witness field for such scripts. With this limit in place, any such a softfork would suddenly require either two different witness commitments, or disabling the previous witness transaction format. Luke