Simply by observing timing from sufficiently geo-graphically and network-ly dispersed nodes, you may deduce the original broadcaster of a transaction. Rotating peers doesn't help.
That said, periodic rotation can be helpful. Every 2-10 minutes is excessive. On Mon, Aug 18, 2014 at 12:46 PM, Ivan Pustogarov <ivan.pustoga...@uni.lu> wrote: > Hi there, > > I'd like to start a discussion on periodic rotation of outbound connections. > E.g. every 2-10 minutes an outbound connections is dropped and replaced > by a new one. > > Motivation: > Each bitcoin non-UPnP client behind NAT has 8 outbound connections > which change only rarely (due to occasional remote side disconnections). > A subset of these 8 entry nodes uniquely identifies a user. > An attacker can listen for transactions in Bitcoin network and for each > transaction record the first 8 peers which forwarded the transaction. > If two distinct transactions (with unrelated bitcoin addresses) > come from the same set of 8 peers, the attacker can conclude that they > originated from the same user. This gives another method (in addition > to transaction graph analysis) for an attacker to link different BC > addresses of the same user. > Also note that by default bitcoin clients advertise their public IP > addresses. The attacker can link the advertised IP's to corresponding > 8 entry nodes and use it to deanonymise Bitcoin clients. > > If a bitcoin client periodically rotates his set of outbound > connections, his 8-peers fingerprint is blurred over time. > > Corresponding pull request is #4723. > > Some details are here: https://www.cryptolux.org/index.php/Bitcoin > > -- > Ivan > > ------------------------------------------------------------------------------ > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- Jeff Garzik Bitcoin core developer and open source evangelist BitPay, Inc. https://bitpay.com/ ------------------------------------------------------------------------------ _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
