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-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UO4Z1-0000En-Sd for bitcoin-development@lists.sourceforge.net; Fri, 05 Apr 2013 11:12:13 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of mckay.com designates 37.1.88.131 as permitted sender) client-ip=37.1.88.131; envelope-from=robert@mckay.com; helo=mail.mckay.com; Received: from mail.mckay.com ([37.1.88.131]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1UO4Z0-0001LK-6a for bitcoin-development@lists.sourceforge.net; Fri, 05 Apr 2013 11:12:11 +0000 Received: from www-data by mail.mckay.com with local (Exim 4.76) (envelope-from ) id 1UO4De-0003Q7-Vw; Fri, 05 Apr 2013 11:50:07 +0100 To: Mike Hearn X-PHP-Originating-Script: 0:func.inc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 05 Apr 2013 11:50:06 +0100 From: Robert McKay In-Reply-To: References: Message-ID: X-Sender: robert@mckay.com User-Agent: Roundcube Webmail/0.5.3 X-Spam-Score: -4.0 (----) 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 SPF_PASS SPF: sender matches SPF record -2.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -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: 1UO4Z0-0001LK-6a Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] A mining pool at 46% 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: Fri, 05 Apr 2013 11:12:13 -0000 On Fri, 5 Apr 2013 11:48:51 +0200, Mike Hearn wrote: > However, youre somewhat right in the sense that its a self-defeating > attack. If the pool owner went bad, he could pull it off once, but > the > act of doing so would leave a permanent record and many of the people > mining on his pool would leave. As he doesnt own the actual mining > hardware, he then wouldnt be able to do it again. Unless all the miners are monitoring the work they do for their pools and the actual miners that found the blocks noticed (unlikely) - the only way anyone knows which pool did anything is the source IP that first disseminates the new block. Also since it's unlikely that both of the doublespend blocks would be found by the same end miner, neither of them would know that the pool operator was responsible even if they were monitoring their work. There's nothing stopping the pool owner from channeling the doublespend blocks through some other previously unknown IP, so I don't think they would suffer any reputational damage from doing this repeatidly. Robert