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 C9F86898 for ; Thu, 17 Nov 2016 10:22:30 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-qk0-f172.google.com (mail-qk0-f172.google.com [209.85.220.172]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 442AF1AC for ; Thu, 17 Nov 2016 10:22:30 +0000 (UTC) Received: by mail-qk0-f172.google.com with SMTP id n204so212415653qke.2 for ; Thu, 17 Nov 2016 02:22:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:cc; bh=/RXUTpd6thu9I4sQGJxKT0vCJHRCsOR2hf32szykWjc=; b=E3mRfXjJU43ApyExxzb5wZ+4NeBJcj5RD4BPK4WfBpdgbL4X8xZZ2/B7Oc1ck0hYZc UqpbFM06xvoFmq/1qRFlNWihk3/+V7oUKSMfgYZMjaa2vdAWIH/Ec+bNGa47xQ+23ScX CjfRjSXzpPthAy8L003WPyU6BREV8z+ewhxAjwsjV6Nnh9EYWFk/7NeBno2oAG/FSGKi N4ll2U7mhWwNdsxWSkSLitka+d/9x6kAleKQxyve2viEx5FSh9sObkuZ9A6TTuftQKuy 8P2Hwre8Wgbo09qgTDPqLjHcwzP040HcOsRNcwAogqqyOqhet9Ro28fAZrPmRqvT3Xel 4vJA== 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:from:date :message-id:subject:cc; bh=/RXUTpd6thu9I4sQGJxKT0vCJHRCsOR2hf32szykWjc=; b=FSr1txJKBQkgBVKXG8UzWWWdDfLubcZz9/Lea59Y8+nO0a3STkl+7QhNlj8nW24A4y HDGy5kgUsf0fwkspvRpVDhnNWtcwGEQgrH3hK4GXG2Of/w8OAT1ax55qcmJjsM7sApju 9qREOmzXwu6RxYgVUIUREIWT0FOCnuGt7BM06eKKav4IkajOHkgqHPLcVC0bX7xnG6C2 qgM/eiHlOBBIpDurCbv7EIp9dlfTfzkK54NIT5rrFX27Cav1DUfa2Mf6ybNzg21joflv gHy8hgfAVVwsu4mqtMMh4JzfX2WU5Ifj6796t9iR7KJIssOYe8wKlHMya3+Bw35bwDsJ OQaA== X-Gm-Message-State: AKaTC01bvxm/T13llSvqFU+JUCnLugnF97Uin5vtvseJMTw1b9RJ6UpmXZBXnqTVrNhCZC1OeRwt+VlmA8+S9w== X-Received: by 10.55.209.150 with SMTP id o22mr2093054qkl.274.1479378149368; Thu, 17 Nov 2016 02:22:29 -0800 (PST) MIME-Version: 1.0 Received: by 10.237.55.227 with HTTP; Thu, 17 Nov 2016 02:22:28 -0800 (PST) In-Reply-To: References: From: Tier Nolan Date: Thu, 17 Nov 2016 10:22:28 +0000 Message-ID: Cc: Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary=001a1147a40414e97b05417c919e X-Spam-Status: No, score=-1.2 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,HTML_MESSAGE,MISSING_HEADERS, RCVD_IN_DNSWL_LOW,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 Subject: Re: [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 10:22:31 -0000 --001a1147a40414e97b05417c919e Content-Type: text/plain; charset=UTF-8 On Thu, Nov 17, 2016 at 12:43 AM, Eric Voskuil wrote: > > This means that all future transactions will have different txids... > rules do guarantee it. > > No, it means that the chance is small, there is a difference. > I think we are mostly in agreement then? It is just terminology. In terms of discussing the BIP, barring a hash collision, it does make duplicate txids impossible. Given that a hash collision is so unlikely, the qualifier should be added to those making claims that require hash collisions rather than those who assume that they aren't possible. You could have said "However nothing precludes different txs from having the same hash, but it requires a hash collision". Thinking about it, a re-org to before the enforcement height could allow it. The checkpoints protect against that though. > As such this is not something that a node > can just dismiss. The security of many parts of the system is based on hash collisions not being possible. --001a1147a40414e97b05417c919e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Thu, Nov 17, 2016 at 12:43 AM, Eric Voskuil <eric@voskuil.org>= ; wrote:
> T= his means that all future transactions will have different txids...
rules do guarantee it.

No, it means that the chance is small, there is a difference.

I think we are mostly in agreement then?=C2=A0 It is= just terminology.

In terms of discussing the BIP, barrin= g a hash collision, it does make duplicate txids impossible.

<= div>Given that a hash collision is so unlikely, the qualifier should be add= ed to those making claims that require hash collisions rather than those wh= o assume that they aren't possible.

You could have sa= id "However nothing precludes different txs f= rom having the same hash, but it requires a hash collision".
Thinking about it, a re-org to before the enforcement heigh= t could allow it.=C2=A0 The checkpoints protect against that though.
=C2=A0
A= s such this is not something that a node
can just dismiss.

The security of many par= ts of the system is based on hash collisions not being possible.
<= /div>
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