Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TRQoL-0006qR-P8 for bitcoin-development@lists.sourceforge.net; Thu, 25 Oct 2012 17:01:37 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.216.54 as permitted sender) client-ip=209.85.216.54; envelope-from=gmaxwell@gmail.com; helo=mail-qa0-f54.google.com; Received: from mail-qa0-f54.google.com ([209.85.216.54]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1TRQoI-0001Cm-5C for bitcoin-development@lists.sourceforge.net; Thu, 25 Oct 2012 17:01:37 +0000 Received: by mail-qa0-f54.google.com with SMTP id p27so2387806qat.13 for ; Thu, 25 Oct 2012 10:01:28 -0700 (PDT) MIME-Version: 1.0 Received: by 10.224.42.80 with SMTP id r16mr9281614qae.90.1351184488779; Thu, 25 Oct 2012 10:01:28 -0700 (PDT) Received: by 10.49.107.103 with HTTP; Thu, 25 Oct 2012 10:01:28 -0700 (PDT) In-Reply-To: References: Date: Thu, 25 Oct 2012 13:01:28 -0400 Message-ID: From: Gregory Maxwell To: Mike Hearn 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: 1TRQoI-0001Cm-5C Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Draft BIP for Bloom filtering 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, 25 Oct 2012 17:01:37 -0000 On Thu, Oct 25, 2012 at 12:56 PM, Gregory Maxwell wrote: > I still don't understand what purpose the apparently gratuitous > inefficiency of constantly resending common tree fragments. Sorry for the rapid additional comment, but I should also have mentioned that the in efficiency is at odds with the privacy argument for the particular mechanism... if the filter is not set at least somewhat too broadly then it will uniquely identify the user. The inefficiency, however, argues for setting the filter as narrowly as possible because there is much more bandwidth used for a wider filter than would be otherwise.