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 892EEE80 for ; Fri, 28 Aug 2015 20:45:32 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-lb0-f170.google.com (mail-lb0-f170.google.com [209.85.217.170]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A6E5D225 for ; Fri, 28 Aug 2015 20:45:31 +0000 (UTC) Received: by lbcbn3 with SMTP id bn3so36532576lbc.2 for ; Fri, 28 Aug 2015 13:45:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=NBnH1bkW22xFwGseslvi8kQfB3u+lMoPIU8WNEoLW7k=; b=VXxbfSr5xvYf7g38L3QdKCg+6y3IIGjPzJBjILvbC9AFyuJtSWIp+mGXymrt09tuhx BnkG0NG0smd6UUobDXzc8hed7Sz/YwbNP5XKo18kRAb/u6g4zE7skEhV7eDeZ2mzSwpw qYlCcSkuk4ZtFw+2ghFf+wPILnI/RtKs21V+b8f2Vt8l52m8+qezKqhJfyYK0jyHqqv7 xjGxjtKnmaRE5l1CWL93qwvnSgFUiJqPCv7S7uQU8TGUBSU/3gO1uz2u0qXLH2PAgLHZ At88o2NlQKOl7LhNQH6PMINYHPMEVW6HTQCTVSZTF9hqzPyi5DFLayZJ+1cEOIVRiTTx CJOQ== X-Gm-Message-State: ALoCoQlnGJdNC1D2siPIbPXsyhoYA8ML7hP/yLQRv7fVZKUoy6egJ2f5eEGBjGqj8eDj38jHIWE1 MIME-Version: 1.0 X-Received: by 10.152.219.3 with SMTP id pk3mr5693164lac.114.1440794729608; Fri, 28 Aug 2015 13:45:29 -0700 (PDT) Received: by 10.25.15.22 with HTTP; Fri, 28 Aug 2015 13:45:29 -0700 (PDT) In-Reply-To: <2081350.pl7B3yspcG@crushinator> References: <2081350.pl7B3yspcG@crushinator> Date: Fri, 28 Aug 2015 22:45:29 +0200 Message-ID: From: =?UTF-8?B?Sm9yZ2UgVGltw7Nu?= To: Matt Whitlock Content-Type: text/plain; charset=UTF-8 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 Subject: Re: [bitcoin-dev] Uniquely identifying forked chains 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, 28 Aug 2015 20:45:32 -0000 On Fri, Aug 28, 2015 at 10:15 PM, Matt Whitlock via bitcoin-dev wrote: > Why would you use a hash of hashes? Wouldn't it be simpler and just as effective to use either: > > 1) the genesis block hash, or If it's a new chain, we're talking about a "spinoffs" https://bitcointalk.org/index.php?topic=563972.0 > 2) the block hash of the first block in a fork? Yes, this seems like the best solution in the schism hardfork case. What both sides of a schism hardfork would want is to avoid hurting bystander users who can't tell the difference between the old and the new currency/chain. I should extend BIP99's section on schism hardforks. Anybody else is welcomed to propose changes to the BIP draft, just PR to this branch: https://github.com/jtimon/bips/tree/bip-forks > Every block hash in a chain implicitly subsumes the genesis block hash of that chain, so there's no need to incorporate the genesis block hash again. > > > On Saturday, 29 August 2015, at 1:27 am, gladoscc via bitcoin-dev wrote: >> There has been discussion of using the genesis block hash to identify >> chains in BIP 21 (bitcoin:// URI scheme). However, this does not allow >> identification between blockchain forks building upon the same genesis >> block. While many see this as undesirable, I think it is inevitable that >> this will eventually happen at some point, and think it is best to build >> systems redundantly. >> >> I propose identifying blockchains for BIP 21 and any other relevant needs >> through: >> >> 1) the genesis block hash for a new chain, or >> 2) a hash of the genesis block hash, concatenated with block hash(es) of >> fork point(s) for a fork chain >> >> This would support forks, forks of forks, forks of forks of forks, etc >> while preserving a fixed length chain identifier. >> >> If a user wants to specify "whatever chain is the longest with PoW", they >> would use (1). In times where multiple chains are coexisting and being >> actively mined, a user can use (2) to specifically identify a chain. >> >> Thoughts? > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev