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-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Vdpi8-0002uq-HL for bitcoin-development@lists.sourceforge.net; Tue, 05 Nov 2013 23:07:00 +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 1Vdpi7-0000Yg-Lu for bitcoin-development@lists.sourceforge.net; Tue, 05 Nov 2013 23:07:00 +0000 Received: by mail-lb0-f182.google.com with SMTP id w6so7192982lbh.13 for ; Tue, 05 Nov 2013 15:06:53 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.152.140.193 with SMTP id ri1mr5651lab.23.1383692812914; Tue, 05 Nov 2013 15:06:52 -0800 (PST) Received: by 10.112.63.164 with HTTP; Tue, 5 Nov 2013 15:06:52 -0800 (PST) In-Reply-To: References: Date: Tue, 5 Nov 2013 15:06:52 -0800 Message-ID: From: Gregory Maxwell To: Drak Content-Type: text/plain; charset=UTF-8 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 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: zikula.org] X-Headers-End: 1Vdpi7-0000Yg-Lu Cc: Bitcoin Development Subject: Re: [Bitcoin-development] Possible Solution To SM Attack 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: Tue, 05 Nov 2013 23:07:00 -0000 On Tue, Nov 5, 2013 at 2:15 PM, Drak wrote: > If I understand the issue properly, this seems like a pretty elegant > solution: if two blocks are broadcast within a certain period of eachother, > chose the lower target. That's a provable fair way of randomly choosing the > winning block and would seem like a pretty simply patch. uh. and so when my solution is, by chance, unusually low... I am incentivized to hurry up and release my block because? I've simulated non-first-block-heard strategies in the past (in the two nearly tied miner with network latency model) and they result in significant increase in large (e.g. >>6 block) reorgs). It's easy to make convergence worse or to create additional perverse incentives.