Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 581F47A9 for ; Thu, 17 Nov 2016 00:06:47 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-vk0-f41.google.com (mail-vk0-f41.google.com [209.85.213.41]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id BF2DA24C for ; Thu, 17 Nov 2016 00:06:46 +0000 (UTC) Received: by mail-vk0-f41.google.com with SMTP id w194so128854335vkw.2 for ; Wed, 16 Nov 2016 16:06:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jtimon-cc.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to:cc; bh=7Nm9tFQdT87r9r+hOzwXZMQbdz3xZAlpL+5EdIjnQy0=; b=R1JfwqTGRDkqJZcDVfOY53jgjMkRzQprtpnIiVbvUP6rJ4AZHoam7vVPr5DZBqMd78 VrNlYMlGEInUT6Ch80ohFeszvHKZ+glfnYqrV+OrjeywSAacNBkBBo/553/W+maiohVa 9u+uc5r7+o/K4ZTj7RcVv0N3Qjo3Apgzn7gSaO32mUX6uvjTxJXfPRnJyHCtaQs7E9wt 4WSgaunGQ4FhULmAOVx5nN5xth39P3qNZB1tLrMYnm86fs5wRIZr3juSMKuw4PbXmqGe Wd0IXEnUdP4NRJbJsnKqP3uQ2zv0lEx4e9yxjPpBb1yDsKlRL4NA6X6efzdzBt88X+/D PPmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=7Nm9tFQdT87r9r+hOzwXZMQbdz3xZAlpL+5EdIjnQy0=; b=Li/hRUEq9XMDt8iEMc+c78vE4fyp+1Fcp8Cbs8AIztN/3Kuw/3PIs6mPLAmoB9ODco VH9wnSdft7pkyV43VYBNpbF0BKpVsFi2IKz8K1hJEBQNrfXrHGr6t9jRCIKrSDTEptRk jSuWVMci7zdvcE7jvO6Lr3uNDzU7+GyuMZ3ygY1e+VsYtjKAFVpSk5Of7gKZrNBxmIcy JBiSHdn5+T2VpdPrUt8i1qjMAcbLtPeUC7+byaGNnWB/XnyGCxyKbb1gK9368IB2mIQ9 zJ2GJ2GhPfELtYzrf5CIqKYBO0sSTvKPnSJGsXisrL32dMjXIeg0l/CpMjZ9Sbd7x5nU X/UQ== X-Gm-Message-State: AKaTC02N+FbFyUYFLdQ+4OQjjdOtNLnSym2bRvImLTs/rom5TzN4Tmnr1Q8m157YiDNOP/1whmdkvUcIpu/1lw== X-Received: by 10.31.70.193 with SMTP id t184mr110952vka.102.1479341205882; Wed, 16 Nov 2016 16:06:45 -0800 (PST) MIME-Version: 1.0 Received: by 10.31.41.15 with HTTP; Wed, 16 Nov 2016 16:06:45 -0800 (PST) From: =?UTF-8?B?Sm9yZ2UgVGltw7Nu?= Date: Thu, 17 Nov 2016 01:06:45 +0100 Message-ID: To: Eric Voskuil Content-Type: text/plain; charset=UTF-8 X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Bitcoin Protocol Discussion , Thomas Kerin Subject: [bitcoin-dev] BIP30 and BIP34 interaction (was Re: [BIP Proposal] 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: Thu, 17 Nov 2016 00:06:47 -0000 On Thu, Nov 17, 2016 at 1:00 AM, Eric Voskuil wrote: > This is a misinterpretation of BIP30. Duplicate transaction hashes can > and will happen and are perfectly valid in Bitcoin. BIP34 does not > prevent this. Sorry for moving the topic, but isn't duplication of tx hashes precisely what BIP30 prevents? That was my undesrtanding but should read it again. Since regular txs take inputs, the collision is extremely unlikely (again, this is my understanding, please correct me when wrong), the worrying case is coinbase txs (which don't have input to take entropy from). By introducing the committed height, collisions on coinbase txs are prevented too. If I'm wrong on any of this I'm more than happy to learn why.