----- Forwarded message from Gregory Maxwell <gmaxwell@gmail.com> ----- Date: Fri, 19 Jul 2013 09:33:45 -0700 From: Gregory Maxwell <gmaxwell@gmail.com> To: tor-talk@lists.torproject.org Subject: Re: [tor-talk] Network diversity [was: Should I warn against Tor?] Reply-To: tor-talk@lists.torproject.org On Fri, Jul 19, 2013 at 8:35 AM, Jens Lechtenboerger <tortalk@informationelle-selbstbestimmung-im-internet.de> wrote:

[For those who are confused about the context of this: I started the original thread. A write-up for my motivation is available at [0].] I Links to my code and a README.txt clarifying necessary prerequisites are available at [0]. Best wishes Jens [0] https://blogs.fsfe.org/jens.lechtenboerger/2013/07/19/how-i-select-tor-guard...

It's _very_ hard to reason about this subject and act safely. It is common for ISPs to use segments in their network which are provided by third party providers, even providers who are almost entirely facilities based will have some holes or redundancy gaps. Because these are L1 (wave) and L2 (e.g. ethernet transport) they are utterly invisible from the L3 topology. You can make some guesses which are probably harmless: a guard that is across the ocean is much more likely to take you across a compromised path than one closer— but going much further than that may well decrease your security. These concerns should be reminding us of the importance of high latency mix networks... they're the only way to start getting any real confidence against a global passive observer, and the are mostly a missing item in our privacy tool toolbelt. _______________________________________________ tor-talk mailing list tor-talk@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://ativel.com http://postbiota.org AC894EC5: 38A5 5F46 A4FF 59B8 336B 47EE F46E 3489 AC89 4EC5