From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WdEsS-0004Hx-LL for bitcoin-development@lists.sourceforge.net; Thu, 24 Apr 2014 08:19:28 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.217.182 as permitted sender) client-ip=209.85.217.182; envelope-from=gmaxwell@gmail.com; helo=mail-lb0-f182.google.com; Received: from mail-lb0-f182.google.com ([209.85.217.182]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WdEsQ-0001pw-PL for bitcoin-development@lists.sourceforge.net; Thu, 24 Apr 2014 08:19:28 +0000 Received: by mail-lb0-f182.google.com with SMTP id l4so1746458lbv.13 for ; Thu, 24 Apr 2014 01:19:20 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.112.52.104 with SMTP id s8mr213287lbo.7.1398327560139; Thu, 24 Apr 2014 01:19:20 -0700 (PDT) Received: by 10.112.89.68 with HTTP; Thu, 24 Apr 2014 01:19:20 -0700 (PDT) In-Reply-To: References: Date: Thu, 24 Apr 2014 01:19:20 -0700 Message-ID: From: Gregory Maxwell To: Mike Hearn Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -1.6 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (gmaxwell[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1WdEsQ-0001pw-PL Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Apr 2014 08:19:28 -0000 On Thu, Apr 24, 2014 at 12:58 AM, Mike Hearn wrote: > The complexity overhead is trivial - we already used coinbase scriptSigs = for > voting on P2SH, I'm sure it'll be used for voting on other things in futu= re > too. We use coinbase sigs to gauge the safety of enforcing a soft fork several times and not just for P2SH, to determine when enforcement of it will be decisive and not result in risking a partition in the network that might permit transaction reversals. This is not voting. As a feature decision mechanism his is a rather coercive thing because it gives the highest hash-power bidders control even when their interests may be rather thoroughly unaligned with population that owns and uses bitcoin in general, but as a plain indicator of when its safe to enforce a new rule (same mechanism, different motivation=E2=80=94 though= a point is that safe usage means using much more than 50% as the threshold) it works pretty well. > .... that's hugely complex and messy. Yes, making really distributed systems that work in a complex world is hard. It certantly would be /easier/ to just declare miners "trusted parties" and require them to always collude to produce a single consensus view of the world that is always honest and never contradictory, except that it doesn't work. Because they aren't individually trusted or even trustworthy. > Why? Remember deleting coinbases with nothing more than a simple majority= is > already possible in the existing protocol and always has been. Temporarily censoring transactions by orphaning otherwise valid blocks that contain them for as long as you retain a majority is possible and impossible to prevent in this architecture. This isn't the same as deleting. Deleting suggests the common misconception that a majority of miners can do anything they want.