From: Jeff Garzik <jgarzik@bitpay•com>
To: Ivan Pustogarov <ivan.pustogarov@uni•lu>
Cc: Bitcoin Dev <bitcoin-development@lists•sourceforge.net>
Subject: Re: [Bitcoin-development] Outbound connections rotation
Date: Mon, 18 Aug 2014 13:19:15 -0400 [thread overview]
Message-ID: <CAJHLa0PvDz5iEad0w7TvM9O3FSjxRu-noRG-KpC7L-ix6Z0i=A@mail.gmail.com> (raw)
In-Reply-To: <20140818164543.GB31175@localhost.localdomain>
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.pustogarov@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/
next prev parent reply other threads:[~2014-08-18 17:19 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-18 16:46 Ivan Pustogarov
2014-08-18 17:19 ` Jeff Garzik [this message]
2014-08-18 17:21 ` Gregory Maxwell
2014-08-18 17:27 ` Mike Hearn
2014-08-18 17:35 ` Pieter Wuille
[not found] ` <CAPg+sBgzEMAQ03GTE2j82+K2B+Dia6T0z14ZYWsBQ8z8QSVoLg@mail.gmail.com>
[not found] ` <CAAS2fgRT8OQzUkneKwpjD15aLZDivT=hgBMTB63EjN8RBrp+RQ@mail.gmail.com>
2014-08-18 18:13 ` [Bitcoin-development] Fwd: " Gregory Maxwell
2014-08-18 18:38 ` Wladimir
2014-08-18 18:37 ` [Bitcoin-development] " Ivan Pustogarov
2014-08-18 19:37 ` Gregory Maxwell
2014-08-18 20:33 ` Ivan Pustogarov
2014-08-18 20:43 ` Gregory Maxwell
2014-08-18 21:02 ` Ivan Pustogarov
2014-08-18 23:20 ` Gregory Maxwell
2014-08-20 12:59 ` [Bitcoin-development] Proposal: PoW-based throttling of addresses (was: Outbound connections rotation) Isidor Zeuner
2014-08-20 14:41 ` Mike Hearn
2014-08-23 11:53 ` Isidor Zeuner
2014-08-23 13:03 ` Mike Hearn
2014-11-13 22:52 ` Isidor Zeuner
2014-11-18 12:06 ` Mike Hearn
2014-11-27 3:29 ` Isidor Zeuner
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