Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WYJmJ-0003mg-3a for bitcoin-development@lists.sourceforge.net; Thu, 10 Apr 2014 18:32:47 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.213.173 as permitted sender) client-ip=209.85.213.173; envelope-from=pieter.wuille@gmail.com; helo=mail-ig0-f173.google.com; Received: from mail-ig0-f173.google.com ([209.85.213.173]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WYJmI-0000Bk-C5 for bitcoin-development@lists.sourceforge.net; Thu, 10 Apr 2014 18:32:47 +0000 Received: by mail-ig0-f173.google.com with SMTP id hl10so8148379igb.12 for ; Thu, 10 Apr 2014 11:32:41 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.43.156.18 with SMTP id lk18mr2831219icc.77.1397154761017; Thu, 10 Apr 2014 11:32:41 -0700 (PDT) Received: by 10.50.141.135 with HTTP; Thu, 10 Apr 2014 11:32:40 -0700 (PDT) In-Reply-To: References: Date: Thu, 10 Apr 2014 20:32:40 +0200 Message-ID: From: Pieter Wuille To: Paul Rabahy Content-Type: text/plain; charset=ISO-8859-1 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 (pieter.wuille[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: 1WYJmI-0000Bk-C5 Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Chain pruning 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, 10 Apr 2014 18:32:47 -0000 On Thu, Apr 10, 2014 at 8:19 PM, Paul Rabahy wrote: > Please let me know if I have missed something. A 51% attack can make you believe you were paid, while you weren't. Full node security right now validates everything - there is no way you can ever be made to believe something invalid. The only attacks against it are about which version of valid history eventually gets chosen. If you trust hashrate for determining which UTXO set is valid, a 51% attack becomes worse in that you can be made to believe a version of history which is in fact invalid. -- Pieter