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 1Qp91n-0007Qe-Du for bitcoin-development@lists.sourceforge.net; Fri, 05 Aug 2011 01:16:43 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.210.42 as permitted sender) client-ip=209.85.210.42; envelope-from=gavinandresen@gmail.com; helo=mail-pz0-f42.google.com; Received: from mail-pz0-f42.google.com ([209.85.210.42]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-MD5:128) (Exim 4.76) id 1Qp91m-0001kX-8M for bitcoin-development@lists.sourceforge.net; Fri, 05 Aug 2011 01:16:43 +0000 Received: by pzk37 with SMTP id 37so2980612pzk.1 for ; Thu, 04 Aug 2011 18:16:36 -0700 (PDT) MIME-Version: 1.0 Received: by 10.142.216.14 with SMTP id o14mr1342285wfg.204.1312506996225; Thu, 04 Aug 2011 18:16:36 -0700 (PDT) Received: by 10.142.212.13 with HTTP; Thu, 4 Aug 2011 18:16:36 -0700 (PDT) In-Reply-To: <201108041038.47396.luke@dashjr.org> References: <201108041038.47396.luke@dashjr.org> Date: Fri, 5 Aug 2011 11:16:36 +1000 Message-ID: From: Gavin Andresen To: Luke-Jr Content-Type: multipart/alternative; boundary=000e0cd22d1046759804a9b7d969 X-Spam-Score: -0.6 (/) 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 (gavinandresen[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -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 X-Headers-End: 1Qp91m-0001kX-8M Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Blitcoin? (Black Hat 2011) 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, 05 Aug 2011 01:16:43 -0000 --000e0cd22d1046759804a9b7d969 Content-Type: text/plain; charset=ISO-8859-1 Dan gave a brief explanation of "blitcoin" on the forums: https://bitcointalk.org/index.php?topic=34458.0 "As reported, I've got a BitCoin deanonymization mechanism. It's not complicated. Connect to every node in the cloud, discoverable via sweeping/IRC/get_peers messages. The first IP to consistently relay transactions for a given identity, is the given identity. Of course the entire BitCoin cloud doesn't allow inbound connections (although you can do rather evil stuff with UPNP to force that open too). But this isn't a problem -- there's only about 3000 to 8000 IPs that are BitCoin nodes that accept inbound connections. Since everyone else depends on them, you just need to create your own mass cluster of IPs that are a decent chunk of the P2P network. Nodes on average have seven outbound connections, so it should take only a few hundred unique to be one of the first-hop peers even for the outbound-only set." ... so it is a de-anonymize-via IP address not de-anonymize-via Bitcoin address. And might go partway to explaining why we're having trouble with network connectivity... -- -- Gavin Andresen --000e0cd22d1046759804a9b7d969 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Dan gave a brief explanation of "blitcoin" on the forums:

"= Of course the entire BitCoin cloud doesn't allow inbound c= onnections (although you can do rather evil stuff with UPNP to force that o= pen too).=A0 But this isn't a problem -- there's only about 3000 to= 8000 IPs that are BitCoin nodes that accept inbound connections.=A0 Since = everyone else depends on them, you just need to create your own mass cluste= r of IPs that are a decent chunk of the P2P network.=A0 Nodes on average ha= ve seven outbound connections, so it should take only a few hundred unique = to be one of the first-hop peers even for the outbound-only set."

=
... so it is a de-ano= nymize-via IP address not de-anonymize-via Bitcoin address. =A0And might go= partway to explaining why we're having trouble with network connectivi= ty...

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Gavin Andresen

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