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 1S36zE-0004nv-SE for bitcoin-development@lists.sourceforge.net; Thu, 01 Mar 2012 14:28:04 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.161.175 as permitted sender) client-ip=209.85.161.175; envelope-from=gmaxwell@gmail.com; helo=mail-gx0-f175.google.com; Received: from mail-gx0-f175.google.com ([209.85.161.175]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1S36z9-0001ls-3s for bitcoin-development@lists.sourceforge.net; Thu, 01 Mar 2012 14:28:04 +0000 Received: by ggcy3 with SMTP id y3so166311ggc.34 for ; Thu, 01 Mar 2012 06:27:53 -0800 (PST) Received-SPF: pass (google.com: domain of gmaxwell@gmail.com designates 10.52.71.226 as permitted sender) client-ip=10.52.71.226; Authentication-Results: mr.google.com; spf=pass (google.com: domain of gmaxwell@gmail.com designates 10.52.71.226 as permitted sender) smtp.mail=gmaxwell@gmail.com; dkim=pass header.i=gmaxwell@gmail.com Received: from mr.google.com ([10.52.71.226]) by 10.52.71.226 with SMTP id y2mr8032405vdu.78.1330612073733 (num_hops = 1); Thu, 01 Mar 2012 06:27:53 -0800 (PST) MIME-Version: 1.0 Received: by 10.52.71.226 with SMTP id y2mr6763422vdu.78.1330612073482; Thu, 01 Mar 2012 06:27:53 -0800 (PST) Received: by 10.220.151.200 with HTTP; Thu, 1 Mar 2012 06:27:53 -0800 (PST) In-Reply-To: References: <20120229232029.GA6073@vps7135.xlshosting.net> <20120229234558.GA6573@vps7135.xlshosting.net> Date: Thu, 1 Mar 2012 09:27:53 -0500 Message-ID: From: Gregory Maxwell To: Ben Reeves Content-Type: text/plain; charset=UTF-8 X-Spam-Score: -1.4 (-) 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 0.2 AWL AWL: From: address is in the auto white-list X-Headers-End: 1S36z9-0001ls-3s Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Duplicate transactions vulnerability 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, 01 Mar 2012 14:28:05 -0000 On Thu, Mar 1, 2012 at 8:09 AM, Ben Reeves wrote: > One more thing to add. The implementation in the reference patch fixes > the blockchain forking issue however by still allowing spent coinbases > to be disconnected patched clients are still vulnerable to blockchain > corruption. While not an immediate issue it would mean > LoadBlockIndex() would error on restart and could cause problems for > new clients during the initial blockchain download. I am not following you here, can you explain what you're thinking? > Is there a reason not to disallow duplicate coinbases entirely? Because this would make it impossible for nodes to prune the vaules. They'd all forever have to keep a set of all the coinbase hashes in order to perform the test. The height-in-coinbase BIP will make duplicates effectively impossible to create, which is a much more clean behavior.