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 1Qp6Fb-0004iN-41 for bitcoin-development@lists.sourceforge.net; Thu, 04 Aug 2011 22:18:47 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.216.182 as permitted sender) client-ip=209.85.216.182; envelope-from=gmaxwell@gmail.com; helo=mail-qy0-f182.google.com; Received: from mail-qy0-f182.google.com ([209.85.216.182]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1Qp6Fa-0005QB-Eh for bitcoin-development@lists.sourceforge.net; Thu, 04 Aug 2011 22:18:47 +0000 Received: by qyk9 with SMTP id 9so1366658qyk.13 for ; Thu, 04 Aug 2011 15:18:41 -0700 (PDT) MIME-Version: 1.0 Received: by 10.229.2.155 with SMTP id 27mr1091968qcj.216.1312496321013; Thu, 04 Aug 2011 15:18:41 -0700 (PDT) Received: by 10.229.3.141 with HTTP; Thu, 4 Aug 2011 15:18:40 -0700 (PDT) In-Reply-To: <4E3B18F3.4010605@justmoon.de> References: <201108041423.14176.andyparkins@gmail.com> <201108041922.16956.andyparkins@gmail.com> <1312483196.3109.38.camel@Desktop666> <201108042042.55214.andyparkins@gmail.com> <82CEB610-9821-4928-8A13-30088A59223C@andrewschaaf.com> <1312490305.3109.46.camel@Desktop666> <4E3B18F3.4010605@justmoon.de> Date: Thu, 4 Aug 2011 18:18:40 -0400 Message-ID: From: Gregory Maxwell To: Stefan Thomas Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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: 1Qp6Fa-0005QB-Eh Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Double spend detection to speed up transaction trust 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, 04 Aug 2011 22:18:47 -0000 On Thu, Aug 4, 2011 at 6:10 PM, Stefan Thomas wrote: > Would network support like a MSG_DOUBLESPEND be better? I used to think > yes, but looking at the reality of Transaction Radar, I'm not so sure. > Nothing stops such a service from scaling up and connecting to thousands > of random nodes (especially when the network itself grows bigger), Except for the fact that such a party is a DOS attack on the network which is already short on functioning listeners. I don't have much doubt that people doing the "connect to everyone" are already causing harm. There are some nodes in .ru/.ua which aggressively connect to me (instant reconnects if I hang up on them) which have never passed me a transaction in all my available logs. Alerts scale better=E2=80=94 both can have a place in the ecosystem, they'r= e actually complementary: Alerts are vulnerable to filtering by sibyl attackers but they have deeper network penetration and where filtering doesn't prevent them you don't need a connection to hear them.