From: Isidor Zeuner <cryptocurrencies@quidecco•de>
To: odinn <odinn.cyberguerrilla@riseup•net>
Cc: Bitcoin Development <bitcoin-development@lists•sourceforge.net>
Subject: Re: [Bitcoin-development] Deanonymisation of clients in Bitcoin P2P network paper
Date: Thu, 27 Nov 2014 03:09:47 +0100 (CET) [thread overview]
Message-ID: <20141127020947.A13D2E19A09@quidecco.de> (raw)
In-Reply-To: <54760A50.201@riseup.net>
Hello there,
quote:
> Please see also the following:
>
> https://cpunks.org//pipermail/cypherpunks/2014-November/005971.html
>
I agree about the severity of the Tor/Bitcoin issue, but I see no
point in bashing Bitcoin's financial privacy characteristics as
the linked pages seem to do.
Bitcoin can be useful as a part of a strategy to improve on privacy,
but it does not intend to be a run-and-forget solution for doing so.
A lot of issues found in this context can actually be traced back to
Tor's characteristics already known before. It's just that
Bitcoin makes Tor's deficiencies more measurable - before Bitcoin,
those interested in researching how Tor performs in an automated
context where a much smaller community. In the end, I guess both
projects can benefit from the research we can do now.
> Respect,
>
> - -Odinn
>
> Jeff Garzik:
> > I don't recall being contacted directly, but the attack has been
> > discussed. It relies on a number of conditions. For example, if
> > you are over Tor, they try to kick the machine off Tor, _assuming_
> > that it will fall back to non-Tor. That's only true for dual stack
> > nodes, which are not really 100% anonymous anyway -- you're
> > operating from your public IP anyway.
> >
Generally, it cannot be said that the attack vector described here is
irrelevant for non-dual-stack nodes. An attacker might not be able to
collect IP addresses of Tor-only nodes, but he can try to kick the
users from all Tor exit nodes he does not control, and proceed with
other attacks when a large number of Tor-only users connect through
his Tor exit node(s).
Since this attack vector has been discussed, I started making some
measurements on how effective it is to connect to Bitcoin using Tor,
and I found that the number of connections dropping to near-zero is
a situation which occurs rather frequently, which suggests that there
is still room to improve on the DoS handling.
Best regards,
Isidor
next prev parent reply other threads:[~2014-11-27 2:09 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-26 7:47 Jean-Paul Kogelman
2014-11-26 13:51 ` Jeff Garzik
2014-11-26 17:13 ` odinn
2014-11-27 2:09 ` Isidor Zeuner [this message]
2014-11-27 2:22 ` Gregory Maxwell
2014-11-27 11:06 ` Mike Hearn
2014-11-27 11:27 ` Wladimir
2014-12-08 16:15 ` Isidor Zeuner
2014-12-08 16:59 ` Mike Hearn
2015-01-22 0:44 ` Isidor Zeuner
2015-01-22 13:20 ` Mike Hearn
2014-12-15 13:25 ` Isidor Zeuner
2014-12-01 10:42 ` Isidor Zeuner
2014-11-27 17:44 Mistr Bigs
2014-11-27 20:30 ` Gregory Maxwell
2014-11-28 0:45 Mistr Bigs
2014-11-28 5:30 ` Gregory Maxwell
2014-12-11 11:51 ` Isidor Zeuner
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