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 D412AB90 for ; Fri, 24 Feb 2017 03:02:37 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-it0-f52.google.com (mail-it0-f52.google.com [209.85.214.52]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 3C6F71D2 for ; Fri, 24 Feb 2017 03:02:37 +0000 (UTC) Received: by mail-it0-f52.google.com with SMTP id 203so7561507ith.0 for ; Thu, 23 Feb 2017 19:02:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bittorrent-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=XvuuXEdYs94unoWRaZ4V8+ANDF4aIyZD/B/YugB5RjE=; b=vHuahANwGqRBaboBO9aQ7um+N/XRxy6ngdeVusnlsfc80t/Ix2IxVw2cL6xuVBFMM5 SjoTfKh2W3+kRYb6uU/3XffIrDD20zYHriuzooZ+mUGbtb28UTN83mnLvcOPI/bKc/aK k6uKJ3ZfEa+ubOtHMaYl6IxZ+WcVWtXldLvHRk8xV5cFiHV/XSMBjXQOttADaGhSJJf4 1X0hxU+ivijC23jILW+Rycxw24itB2RyK9dN+BIOMW/0Ei/5wT3txeqob18d2Ngmrjk1 +9sPSzrtcDeRe22ueTiwg9ppBsxOI7z1dkl4N22RoAK+jOhpB4V9cpI6T+7UJ2GOWi1M NOcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=XvuuXEdYs94unoWRaZ4V8+ANDF4aIyZD/B/YugB5RjE=; b=RKuQ+FaQP8d+I20iVu65okUF0eAm2GcKrNWDlYF3ZgF1MK1KG8rdIcvbyopuU7y3Gy C+zIRFvKjWtTz694/b+j3vfLEklVQcLQySaSUYgDS76UUWLAjOjMU2dOrnNL2wPbeQGA 33NVu0PRnKT7vtiajLJC6O2iXALNmw8q/aHp4UJ6V2K1bxaeESC0ohw4qozLklwEay6f ek8vqp4aPb2KZpTv+PsW/tCR1A+MaBduN2oDVO6fMaqTmxZJ6PneaVh34zttrHfLhY7b VZg2GxdKm18n1CIabv+Nn3uVzfI8zb/8ntywyJ+ZoqAc8Nv8PwVWQcn0YoPLmVblAI0r CzGw== X-Gm-Message-State: AMke39nyEGzSj2xmW1rWUn/Y98MoG7MfhAvKL9B0/MIIio/AlqyIDw/faiQLsPQd+REOlaMhGyMCWRfH2DB9Tr+0 X-Received: by 10.36.71.207 with SMTP id t198mr732456itb.98.1487905356671; Thu, 23 Feb 2017 19:02:36 -0800 (PST) MIME-Version: 1.0 Received: by 10.36.73.150 with HTTP; Thu, 23 Feb 2017 19:02:36 -0800 (PST) In-Reply-To: <20170224025811.GA31911@savin.petertodd.org> References: <20170223011506.GC905@savin.petertodd.org> <20170223235105.GA28497@savin.petertodd.org> <20170224010943.GA29218@savin.petertodd.org> <20170224025811.GA31911@savin.petertodd.org> From: Bram Cohen Date: Thu, 23 Feb 2017 19:02:36 -0800 Message-ID: To: Peter Todd Content-Type: multipart/alternative; boundary=001a1145b6643ea69505493df695 X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HTML_MESSAGE, 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 Subject: Re: [bitcoin-dev] A Better MMR Definition 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: Fri, 24 Feb 2017 03:02:38 -0000 --001a1145b6643ea69505493df695 Content-Type: text/plain; charset=UTF-8 On Thu, Feb 23, 2017 at 6:58 PM, Peter Todd wrote: > > So to be clear, do you agree or disagree with me that you *can* extract a > compact proof from a MMR that a given output is unspent? > After wading through your logic on how updates are done, I agree that that can be done, but apples to apples compact proofs can also be done in a utxo commitment, and proofs of the validity of updates can be done in a utxo commitment, so there isn't any performance advantage to all that extra complexity. --001a1145b6643ea69505493df695 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On T= hu, Feb 23, 2017 at 6:58 PM, Peter Todd <pete@petertodd.org> wrote:

So to be clear, do you agree or disagree with me th= at you *can* extract a
compact proof from a MMR that a given output is unspent?

After wading through your logic on how updates are done, = I agree that that can be done, but apples to apples compact proofs can also= be done in a utxo commitment, and proofs of the validity of updates can be= done in a utxo commitment, so there isn't any performance advantage to= all that extra complexity.
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