Block directory authorities, is it possible?

[Kevin Smith]

Why hasn't Tor been blocked in China already? Torpark is redirecting
to the Google homepage (1). The psiphon homepage has been blocked. The
Freegate homepage is blocked. Why not Tor?

Could it be that Tor is being used to help identify suspected
dissidents? Consider the following:

I'm sitting at my home in Beijing using Tor. The Chinese internet
police see my computer periodically connecting to a Tor directory
server or entry node. They know I am using Tor. Ok. Here's someone
using Tor. Who is he? Well, his IP address is linked to Beihang
University. A quick check with the Beihang University IT department
reveals that he is Kevin Smith in building AB apartment XYZ, his
passport number is 123456789, he teaches English and has no record of
political activity aside from voting in those despicable American
national elections. Not too likely that he is a dissident.

Wang Guolu is sitting at home using Tor. The Chinese internet police
see his computer periodically connecting to a Tor directory server or
entry node. They know he is using Tor. Ok. Here's someone using Tor.
Who is he? Well, his IP address is linked to China Netcom in Dalian. A
quick check with Dalian China Netcom reveals that he is Wang Guolu who
lives in building CD apartment UVW on Renmin Lu. His ID number is
987654321, he has a low paying job at a local factory and is suspected
of being a member of the FLG. A relatively low paid factory worker
using advanced internet anonymizing software? That just screams
dissident.

The above situation has been suggested before on the mailing list:
http://archives.seul.org/or/talk/Aug-2006/msg00089.html
http://archives.seul.org/or/talk/Aug-2006/msg00091.html

(1) http://archives.seul.org/or/talk/Dec-2006/msg00076.html

Kevin S.

On 1/13/07, Pei Hanru <peihanru at gmail.com> wrote:
> On 2007-1-13 4:44 CST(UTC+8), Mike Perry wrote:
> >> I live in China and was/am having difficulties in using Tor, the problem
> >> is: it takes quite a long time to build a circuit for the first time I
> >> start Tor on my Windows machine.
> >>
> >> Am I understanding correctly? Are there any actions Tor can take? After
> >> all, we cannot simply assume this will not happen in the future.
> >
> > If the problem right now is just IP blocking you can try the tor
> > option HttpProxy which will route your dirserver traffic through an
> > http proxy you specify. Unfortunately, certain areas have begun
> > blocking by the /tor/ url postfix that dirservers use, independent of
> > IP. There is an option in 1.2.x/SVN to tunnel this traffic via other
> > tor nodes (via SSL), but I believe it is prone to exploding at this
> > point in time.
>
> Actually, no IP is blocked at this time, it is due to a natural disaster. :(
>
> It's interesting to evaluate whether the option you mentioned will
> defend the attack (that is, blocking all directory authorities), in that
> setting, there's no living network-status, how to find "other tor
> nodes"? Manually importing required files is an idea, but, it's not that
> elegant and finding up-to-date files is a problem.
>
> I'm curious on more details. :)
>
> Thanks,
> Hanru
>