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 83FF41024 for ; Sun, 18 Feb 2018 18:57:08 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-lf0-f65.google.com (mail-lf0-f65.google.com [209.85.215.65]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 8A0E23FB for ; Sun, 18 Feb 2018 18:57:06 +0000 (UTC) Received: by mail-lf0-f65.google.com with SMTP id x196so10255237lfd.12 for ; Sun, 18 Feb 2018 10:57:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:cc; bh=WVHQIChxxiMgjtKV1tz1eMae9TDp1lzAN3u0qm+6rgY=; b=FLiE+0h43FQRLL3bXlCvFxOsGay7NLfhP8l2aJArZaXnPyZk6ZHAtqbFSjR7xTst/e KFH3CxCLyqnSVfj66agObysoOtBQ7E00sfni5Jx4ANYpdeVxB4uzhxSWEIsGi2zOlzS6 pLp5y7+aXGJqlvenBat9RBVTAwFw1u5S0WZd/6lsekxj5ijvHKpChHmkazuzVXEtRg5K 9j4diuP6vuhAYPnOeqJJ92ny9Qm+rK9zJDcUyM+TZx42SMAyaPaGlTeL0covc1b1bwqU w6szdPu6g7SlXR2lksqgy2472glnlfl4Oz/ACswVDG9sKU2LyeQVApB9O4kwVHMp6HH0 ecrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:cc; bh=WVHQIChxxiMgjtKV1tz1eMae9TDp1lzAN3u0qm+6rgY=; b=YJavCqmn6Sxv4wdbeSh9gpsf39ml45Pf+HOMwArm+UCPwtkcLYaGRLkMaM2X7uOu6l oyXmOcWy5a4b+XJ+vxxB5oez778RMQtGWEo58wXpdwQPwB8Kia2DmAjENBTHEG6e0GD1 pdUquy7CS0lPc5l2jsXs4229Q8IZ7VScWGAac6kibBKVUEizd09RnsY2Y71p72sP/QSt QKaW0gANOL7HNV5NBXBb0QXOafoTkKMXmewmx818EJxIIBocpdh6UQzu7I8WpHcMYqZF AqVzMVeyHKQ0QtbFjuEgNTbb9pNN6hpk+8sn6VUDBoueRoLhOKRGivWV1+L3EQS6+Jgw j9tQ== X-Gm-Message-State: APf1xPBaHm+RRCSKFpGx+SLkold8BBg4mo2wrXruhApOBSN9yLxlgTSe n3U/sJmWVteiBi+od+K5tVdS76hmnopf8je749kiL+rC X-Google-Smtp-Source: AH8x227aU5PBcQlDUrbV24edVjzyB1AU6FjWxyWX5wC7g9IZNV1hVJ24tINz74V6o8Mqhru+RLdEhIyCIzNEjsMqGqc= X-Received: by 10.46.27.211 with SMTP id c80mr8536805ljf.46.1518980224610; Sun, 18 Feb 2018 10:57:04 -0800 (PST) MIME-Version: 1.0 Sender: famonid@gmail.com Received: by 10.25.230.1 with HTTP; Sun, 18 Feb 2018 10:57:03 -0800 (PST) In-Reply-To: <8fb2e424-268c-7433-5f6b-5fbab5c5cc5c@voskuil.org> References: <8fb2e424-268c-7433-5f6b-5fbab5c5cc5c@voskuil.org> From: Marco Falke Date: Sun, 18 Feb 2018 13:57:03 -0500 X-Google-Sender-Auth: UlXxz74v2ze2WipxydLjLGyz1vs Message-ID: Cc: Bitcoin Protocol Discussion Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, MISSING_HEADERS, RCVD_IN_DNSWL_NONE autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: Re: [bitcoin-dev] Amend the BIP 123 process to include buried deployments 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: Sun, 18 Feb 2018 18:57:08 -0000 > They also do not require software coordination. Therefore, why should there be > BIPs at all? Seems to me that we should instead add these documents to > https://github.com/bitcoin-core/docs Consensus is not trivial. I think documentation is important, even if it seems simple to some. Personally, I don't care too much where to place the documentation, but the BIPs repo seems a good place, since it also hosts other informational documents. To prevent "two BIPs for every protocol change", related buried deployments could be bundled. E.g. the ISM BIP 90 change. On Wed, Feb 14, 2018 at 6:57 PM, Eric Voskuil wrote: > On 02/14/2018 02:01 PM, Marco Falke via bitcoin-dev wrote: >> I define a buried deployment as a consensus rule change that affects >> validity of blocks that are buried by a sufficiently large number of >> blocks in the current valid most-work chain, > > Sufficient for what, specifically? Sufficiently large to prevent potential bike-shedding. The expected number of blocks in two weeks could be considered a lower bound. Then multiply that by 10 or 20. > >> but the current block (and all its parents) remain valid. > > Remain valid in the case where the depth assumption is "sufficient" to > ensure that a chain split is not possible? > > If this was true (which it is not), it would imply that there is no > reason to validate any block deeper than the most recent 25,000. > Presumably this means that people may continuously rely on some > authority (like Bitcoin Core?) to determine the checkpoint for tip-25,000. > Note that a checkpoint *freezes* the chain completely at a given height. Buried deployments are *not* checkpoints. Also note that buried deployments only make sense after a protocol upgrade has happened (i.e. a soft fork or hard fork). If a miner has the resources to cause a chain split, they could trivially do that even in the complete absence of buried deployments. Buried deployments are *not* a solution to 50% attacks. >> BIP 123 suggests that BIPs in the consensus layer should be assigned a >> label "soft fork" or "hard fork". However, I think the differentiation >> into soft fork or hard fork should not be made for BIPs that document >> buried deployments. In contrast to soft forks and hard forks, buried >> deployments do not require community and miner coordination for a safe >> deployment. > > They can only avoid this requirement based on the assumption that the > hard fork cannot result in a chain split. This is not the case. > >> For a chain fork to happen due to a buried deployment, a massive chain >> reorganization must be produced off of a block in the very past. > > In other words a "buried deployment" is a hard fork that is not likely > to cause a chain split. This is a subjective subcategory of hard fork, > not an independent category - unless maybe you can show that there is > the 25,000 blocks number is an objective threshold. Please note that a buried deployment can very well be a soft fork. I think this makes it even clearer, that such a label makes no sense for buried deployments. >> In the extremely unlikely event of such a large chain reorganization, >> Bitcoin's general security assumptions would be violated regardless of >> the presence of a buried deployment. > > This is untrue. The "security assumptions" of Bitcoin do not preclude > deep reorganizations. > e >