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 3DF6014F0 for ; Thu, 4 Apr 2019 03:05:07 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-qt1-f176.google.com (mail-qt1-f176.google.com [209.85.160.176]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A54097E9 for ; Thu, 4 Apr 2019 03:05:06 +0000 (UTC) Received: by mail-qt1-f176.google.com with SMTP id v32so1548771qtc.10 for ; Wed, 03 Apr 2019 20:05:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=oxn6nGKF2qL23JJ8THK8XgXvW/PrewV/kLXEruX+g8E=; b=ahw7byXcL68UJqnn2gzRgjfI1Z/K0KYRK60JN9f9ahkz9sSSYTwEH91G5SkkdRp6T1 hZfkenn0E5PyqcCMdBgVisjrOaPjkIKAgbMVJp966R47EdnClotOpOvDaEDEiTVjEiSV Jg4eUNJYJi1zMJp85MEOUprSP5sLYjaDJWeDE6cewmZ95t4H54udMIr5N41KpO4F1L0f 2/r43lUXtuBFRCsm5zdNuXGWUpvWvZYyIxWVq/8oZbcqXPMmTn02Qt3eHqVmhm0S0JUh Uz5znN9UwCdU+tLAs2nG5RuIY6rk1wdcjSArqpjB2SlhmOLtrJTH4rwRLGkDdTJz3YI7 YL4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=oxn6nGKF2qL23JJ8THK8XgXvW/PrewV/kLXEruX+g8E=; b=QV1g8YM6rm4Btnf2Uv1alPUO50a6u4DFJM8UZRifHgZe1ZPjd/jH7JycKTziCLf+29 oz7OI6rKK5bltLxOKx4WD6TO7rHuoeCYINgJhvtvynJ7gBd1x1dJMNl3zwlpaZ9p/Mqd HLA//5plB/cPuJTdORNLH6KtSSNeIkVjfJKay6YcaYioBP5Fkt8SAfi4b3HkY0d3MaER Yhb8vzT1TxVLtmWCl+WY39tqRhokv8ybi0MgIJC0OeVy1AXKgtjp7FWLfpqqaZLLWvc1 gJ/VnF7XzNzP9w3nzrciVGmxBqw8O60hh3PWZLqFGIGfLpO0MQf6Qw9rai21DbkymMYn C0JQ== X-Gm-Message-State: APjAAAWhyWltKLBIDXZI70jCUgcvg9O7KqOJIzOiA3jbs2HJXH6ElM47 ZmoFsuZSQJ9+eCdxY/5hxf7GjhMGpcNVtKjvTaY= X-Google-Smtp-Source: APXvYqw7939um686w4AL2P1GjzzA1eAJ4ScQuuN2rHqn3vgKkvqMBs+kAqEL913MpmtSybtHRd7ALsRN0t40QNeX/4c= X-Received: by 2002:a0c:af74:: with SMTP id j49mr2778171qvc.129.1554347105832; Wed, 03 Apr 2019 20:05:05 -0700 (PDT) MIME-Version: 1.0 References: <816FFA03-B4D9-4ECE-AF15-85ACBFA4BA8F@jonasschnelli.ch> <201904040248.34162.luke@dashjr.org> In-Reply-To: <201904040248.34162.luke@dashjr.org> From: Ethan Scruples Date: Wed, 3 Apr 2019 23:04:58 -0400 Message-ID: To: Luke Dashjr Content-Type: multipart/alternative; boundary="00000000000019d1310585aba3ee" X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, HTML_MESSAGE, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Thu, 04 Apr 2019 05:05:32 +0000 Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] assumeutxo and UTXO snapshots 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, 04 Apr 2019 03:05:07 -0000 --00000000000019d1310585aba3ee Content-Type: text/plain; charset="UTF-8" > This is exactly the danger. UTXO snapshots are NOT an alternative to a real IBD. There are HUGE security implications for this. This is a perfect example of what I am talking about when I say that people do not appear to notice that there is no important security implication to be found here. If there are huge security implications for this, then I am keen to hear them. In the scenario I have described, what advantage does Bob have over Alice? What actionable information has Bob gained, and what is the action he can take with it in hand? What value does Bob receive in return for the electricity he has spent validating the previous blocks? I cannot find any, but I am open to hearing the answer, and I think others would benefit from knowing it as well. On Wed, Apr 3, 2019 at 10:49 PM Luke Dashjr wrote: > On Wednesday 03 April 2019 15:39:29 Ethan Scruples via bitcoin-dev wrote: > > If we can get mandatory UTXO commitments soft forked into Bitcoin, we get > > the advantage of a non-growing IBD, > > No, we don't. This is exactly the danger. UTXO snapshots are NOT an > alternative to a real IBD. There are HUGE security implications for this. > Frankly, the danger that someone would do such a thing is itself a good > reason not to ever add UTXO commitments. > > Luke > --00000000000019d1310585aba3ee Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
> This is exactly the danger. UTXO snapshots are NOT an= =C2=A0alternative to a real IBD. There are HUGE security implications for t= his.=C2=A0

This is a perfect example of what I am ta= lking about when I say that people do not appear to notice that there is no= important security implication to be found here.

= If there are huge security implications for this, then I am keen to hear th= em. In the scenario I have described, what advantage does Bob have over Ali= ce? What actionable information has Bob gained, and what is the action he c= an take with it in hand? What value does Bob receive in return for the elec= tricity he has spent validating the previous blocks? I cannot find any, but= I am open to hearing the answer, and I think others would benefit from kno= wing it as well.

On Wed, Apr 3, 2019 at 10:49 PM Luke Dashjr <luke@dashjr.org> wro= te:
On Wednesday= 03 April 2019 15:39:29 Ethan Scruples via bitcoin-dev wrote:
> If we can get mandatory UTXO commitments soft forked into Bitcoin, we = get
> the advantage of a non-growing IBD,

No, we don't. This is exactly the danger. UTXO snapshots are NOT an alternative to a real IBD. There are HUGE security implications for this. <= br> Frankly, the danger that someone would do such a thing is itself a good reason not to ever add UTXO commitments.

Luke
--00000000000019d1310585aba3ee--