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 CC32C1E40 for ; Thu, 1 Oct 2015 02:15:14 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from ozlabs.org (ozlabs.org [103.22.144.67]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 6DD0D16E for ; Thu, 1 Oct 2015 02:15:14 +0000 (UTC) Received: by ozlabs.org (Postfix, from userid 1011) id AC657140D6C; Thu, 1 Oct 2015 12:15:11 +1000 (AEST) From: Rusty Russell To: Gregory Maxwell In-Reply-To: References: <87zj04fxkw.fsf@rustcorp.com.au> User-Agent: Notmuch/0.17 (http://notmuchmail.org) Emacs/24.4.1 (x86_64-pc-linux-gnu) Date: Thu, 01 Oct 2015 09:56:51 +0930 Message-ID: <87bncjph6c.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, T_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 Cc: Bitcoin Dev , Pieter Wuille Subject: Re: [bitcoin-dev] Versionbits BIP (009) minor revision proposal. 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: Thu, 01 Oct 2015 02:15:14 -0000 Gregory Maxwell writes: > I can, however, argue it the other way (and probably have in the > past): The bit is easily checked by thin clients, so thin clients > could use it to reject potentially ill-fated blocks from non-upgraded > miners post switch (which otherwise they couldn't reject without > inspecting the whole thing). This is an improvement over not forcing > the bit, and it's why I was previously in favor of the way the > versions were enforced. But, experience has played out other ways, > and thin clients have not done anything useful with the version > numbers. > > A middle ground might be to require setting the bit for a period of > time after rule enforcing begins, but don't enforce the bit, just > enforce validity of the block under new rules. Thus a thin client > could treat these blocks with increased skepticism. Introducing this later would trigger warnings on older clients, who would consider the bit to represent a new soft fork :( So if we want this middle ground, we should sew it in now, though it adds a other state. Simplest is to have miners keep setting the bit for another 2016 blocks. If we want to later, we can make this a consensus rule. "Bitcoin is hard, let's go shopping!" "With Bitcoin!" "..." Rusty.