- cypherpunks - lists.cpunks.org

Re: [tor-talk] Network diversity [was: Should I warn against Tor?]
by Eugen Leitl 20 Jul '13

20 Jul '13

----- Forwarded message from Gregory Maxwell <gmaxwell(a)gmail.com> ----- Date: Fri, 19 Jul 2013 13:42:03 -0700 From: Gregory Maxwell <gmaxwell(a)gmail.com> To: tor-talk(a)lists.torproject.org Subject: Re: [tor-talk] Network diversity [was: Should I warn against Tor?] Reply-To: tor-talk(a)lists.torproject.org On Fri, Jul 19, 2013 at 9:45 AM, adrelanos <adrelanos(a)riseup.net> wrote: > Seems like high latency mix networks failed already in practice. [1] > > Can't we somehow get confidence even against a global active adversary > for low latency networks? Someone start a founding campaign? So have low latency ones, some things fail. Today you'd answer that concern by running your high latency mix network over tor (or integrated into tor) and so it cannot be worse. Answering the "you need users first, and low latency networks are easier to get users for" concern. The point there remains that if you're assuming a (near) global adversary doing timing attacks you cannot resist them effectively using a low latency network. Once you've taken that as your threat model you can wax all you want about how low latency mix networks get more users and so on.. it's irrelevant because they're really not secure against that threat model. (Not that high latency ones are automatically secure either— but they have a fighting chance) On Fri, Jul 19, 2013 at 10:03 AM, Jens Lechtenboerger <tortalk(a)informationelle-selbstbestimmung-im-internet.de> wrote: >> but going much further than that may well decrease your security. > > How, actually? I’m aware that what I’m doing is a departure from > network diversity to obtain anonymity. I’m excluding what I > consider unsafe based on my current understanding. It might be that > in the end I’ll be unable to find anything that does not look unsafe > to me. I don’t know what then. Because you're lowering the entropy of the nodes you are selecting maybe all the hosts themselves are simply NSA operated, or if not now, they be a smaller target to compromise. Maybe it actually turns out that they all use a metro fiber provider in munich which is owned by an NSA shell company. In Germany this may not be much of a risk. But if your logic is applied to someplace that is less of a hotbed of Tor usage it wouldn't be too shocking if all the nodes there were run by some foreign intelligence agency. _______________________________________________ tor-talk mailing list tor-talk(a)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

1 0

Re: [tor-talk] Network diversity [was: Should I warn against Tor?]
by Eugen Leitl 20 Jul '13

20 Jul '13

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

1 0

back on the airwaves
by Riad S. Wahby 20 Jul '13

20 Jul '13

All, Welcome back to the Cypherpunks mailing list. You've received a subscription notice and are receiving this message now because you were a member of the cypherpunks(a)al-qaeda.net or cypherpunks(a)jfet.org mailing list before it went offline several (?) weeks ago. First, my sincerest apologies for having failed to notice that messages were silently dropping. All the bounces were still dropping into my "cypherpunks bounces" mailbox, so from what I could tell all was running normally (if perhaps at slightly low SNR). It turns out that some package upgrade, most likely a new version of perl, broke majordomo. (And of course, could I have picked a worse time to break everything?) Well, that's the bad news. The good news is that cypherpunks is now powered by Mailman, and should be a bit more reliable, easier to maintain, and less Rube-Goldbergian. (I say this with all respect to my cpunk admin predecessors; the CDR was a useful and interesting piece of software, but---at least, in its most recent form---it was certainly not a *pretty* piece of software.) Nevertheless, since I haven't actually done much other than port the old majordomo list over to mailman, the Distributed Remailer functionality no longer obtains. Practically, this hasn't mattered for at least the last 6 or 8 years, but perhaps that would change if I would just modernize the software a bit. I'm planning on putting some thought into that in the near future, but for now I figured it was more important to just get *something* back up and running. Once again, welcome back! -=rsw

1 0