From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TRkn5-0000es-Lj for bitcoin-development@lists.sourceforge.net; Fri, 26 Oct 2012 14:21:39 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.212.175 as permitted sender) client-ip=209.85.212.175; envelope-from=mh.in.england@gmail.com; helo=mail-wi0-f175.google.com; Received: from mail-wi0-f175.google.com ([209.85.212.175]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1TRkn4-0007EZ-VS for bitcoin-development@lists.sourceforge.net; Fri, 26 Oct 2012 14:21:39 +0000 Received: by mail-wi0-f175.google.com with SMTP id hq4so380929wib.10 for ; Fri, 26 Oct 2012 07:21:32 -0700 (PDT) MIME-Version: 1.0 Received: by 10.216.201.156 with SMTP id b28mr13909091weo.4.1351261292804; Fri, 26 Oct 2012 07:21:32 -0700 (PDT) Sender: mh.in.england@gmail.com Received: by 10.216.236.30 with HTTP; Fri, 26 Oct 2012 07:21:32 -0700 (PDT) In-Reply-To: References: Date: Fri, 26 Oct 2012 16:21:32 +0200 X-Google-Sender-Auth: 32qRHUrXx-x-qnemW0_SU5I4vaM Message-ID: From: Mike Hearn To: Gregory Maxwell Content-Type: text/plain; charset=UTF-8 X-Spam-Score: -1.5 (-) 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 (mh.in.england[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 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: 1TRkn4-0007EZ-VS 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: Fri, 26 Oct 2012 14:21:39 -0000 > Because I can potentially waste bandwidth of all nodes forever (well as long > as users are still scanning blocks with my transactions in them) with O(1) work. And this gets you what? Users who have active wallets will have their bandwidth wasted for as long as you keep up the attack. Once you stop active wallets won't be rescanning that part of the chain and new users won't be scanning it either, as they skip blocks before their earliest key time using getheaders. So basically you can waste the bandwidth of active users for a while, by spamming transactions. This is not a new attack. Anyway, it's trivial to DoS the entire Bitcoin network today. It hasn't ever happened. Maybe one day it will, but the only rationale people can come up with for such an attack beyond random griefing is governments, and complexity attacks are really not their style. Much easier to just pass a law. I'm not saying DoS should be ignored, but I do feel there are limits to how far down that rabbithole it's worth going.