Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Qesdu-0006St-M1 for bitcoin-development@lists.sourceforge.net; Thu, 07 Jul 2011 17:45:38 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.216.47 as permitted sender) client-ip=209.85.216.47; envelope-from=gmaxwell@gmail.com; helo=mail-qw0-f47.google.com; Received: from mail-qw0-f47.google.com ([209.85.216.47]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1Qesdt-0006qI-KE for bitcoin-development@lists.sourceforge.net; Thu, 07 Jul 2011 17:45:38 +0000 Received: by qwh5 with SMTP id 5so780337qwh.34 for ; Thu, 07 Jul 2011 10:45:32 -0700 (PDT) MIME-Version: 1.0 Received: by 10.229.131.66 with SMTP id w2mr802490qcs.254.1310060732035; Thu, 07 Jul 2011 10:45:32 -0700 (PDT) Received: by 10.229.83.196 with HTTP; Thu, 7 Jul 2011 10:45:31 -0700 (PDT) In-Reply-To: References: <201107071049.48131.andyparkins@gmail.com> Date: Thu, 7 Jul 2011 13:45:31 -0400 Message-ID: From: Gregory Maxwell To: Mike Hearn 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 AWL AWL: From: address is in the auto white-list X-Headers-End: 1Qesdt-0006qI-KE Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Suggestion for enhancements to getblock 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, 07 Jul 2011 17:45:38 -0000 On Thu, Jul 7, 2011 at 11:42 AM, Mike Hearn wrote: [snip] > You have to treat appearing deep in the chain as ipso-facto proof of > validity. Lightweight/SPV clients simply must have that trust, it > cannot be done any other way. See this article: > > http://code.google.com/p/bitcoinj/wiki/SecurityModel It _could_ be done another way, with a protocol change: http://forum.bitcoin.org/index.php?topic=21995.0