From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TCBci-0003yg-SH for bitcoin-development@lists.sourceforge.net; Thu, 13 Sep 2012 15:46:36 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of eigbox.net designates 66.96.186.17 as permitted sender) client-ip=66.96.186.17; envelope-from=SRS0=nh6BJu=HM=godofgod.co.uk=matthewmitchell@eigbox.net; helo=bosmailout17.eigbox.net; Received: from bosmailout17.eigbox.net ([66.96.186.17]) by sog-mx-4.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1TCBcd-0004pf-Fd for bitcoin-development@lists.sourceforge.net; Thu, 13 Sep 2012 15:46:36 +0000 Received: from bosmailscan15.eigbox.net ([10.20.15.15]) by bosmailout17.eigbox.net with esmtp (Exim) id 1TCBcX-0003MV-63 for bitcoin-development@lists.sourceforge.net; Thu, 13 Sep 2012 11:46:25 -0400 Received: from bosimpout01.eigbox.net ([10.20.55.1]) by bosmailscan15.eigbox.net with esmtp (Exim) id 1TCBcX-0004gp-A3 for bitcoin-development@lists.sourceforge.net; Thu, 13 Sep 2012 11:46:25 -0400 Received: from bosauthsmtp18.eigbox.net ([10.20.18.18]) by bosimpout01.eigbox.net with NO UCE id yfmR1j0060PPbB601fmRbc; Thu, 13 Sep 2012 11:46:25 -0400 X-Authority-Analysis: v=2.0 cv=aPZHX8Bm c=1 sm=1 a=Vnyysazsc9gF4v5jbSvB8A==:17 a=Goz4v7xpImgA:10 a=JhU9KSwl1l8A:10 a=RmqW3wxksLsA:10 a=kj9zAlcOel0A:10 a=eGitJVp2AAAA:8 a=-aUnnjAAwhoA:10 a=pGLkceISAAAA:8 a=whf8sheV4CzZn4JTefsA:9 a=CjuIK1q_8ugA:10 a=MSl-tDqOz04A:10 a=hsonH7E3nOZjOFuRJksPKA==:117 X-EN-OrigOutIP: 10.20.18.18 X-EN-IMPSID: yfmR1j0060PPbB601fmRbc Received: from [109.175.173.27] by bosauthsmtp18.eigbox.net with esmtpsa (TLSv1:AES128-SHA:128) (Exim) id 1TCBcW-0005fw-Ln for bitcoin-development@lists.sourceforge.net; Thu, 13 Sep 2012 11:46:25 -0400 From: Matthew Mitchell Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Date: Thu, 13 Sep 2012 16:46:21 +0100 References: <2B95CF41-4304-4D2A-9ABF-198D97B7449B@godofgod.co.uk> To: "bitcoin-development@lists.sourceforge.net" Message-Id: <1C04E92E-D53F-4914-B0AC-A002AAB5F978@godofgod.co.uk> Mime-Version: 1.0 (Mac OS X Mail 6.0 \(1486\)) X-Mailer: Apple Mail (2.1486) X-EN-UserInfo: c68a83c59c94ef03b40bb4bc312c51e4:dffc0a9b4c8a0435ad832ff5852cab82 X-EN-AuthUser: godofgod@godofgod.co.uk Sender: Matthew Mitchell X-EN-OrigIP: 109.175.173.27 X-EN-OrigHost: unknown X-Spam-Score: -1.0 (-) 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 -0.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 1.1 AWL AWL: From: address is in the auto white-list X-Headers-End: 1TCBcd-0004pf-Fd Subject: Re: [Bitcoin-development] Segmented Block Relaying BIP draft. 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, 13 Sep 2012 15:46:36 -0000 On 13 Sep 2012, at 16:16, Gregory Maxwell wrote: > Sorry, I'm still not seeing what the value is. How is the tree level > useful to anyone? If you did want to get only parts of the > transaction list, why not just ranges from the lowest level? Obtaining a particular tree level allows you to verify segments without = needing to download all the transaction hashes first. You only need one = hash per segment. For instance if you want to divide the block into 8 = segments you specify level 3 and download 8 hashes. You could download = all transaction hashes if you wanted and it would still work, it just = requires more data transfer for the hashes. This was the reason why = merkle trees were used in bitcoin, to avoid requiring all hashes to = verify data.