Block directory authorities, is it possible?

[Kevin Smith]

I have never heard that the Tor website http://tor.eff.org/ has been
blocked in China, nor any URLs under that website. It is currently not
blocked by my ISP in Beijing, nor was it blocked by my ISP in Shandong
province when I lived there.

I was, however, referring to the Tor service itself, not the website,
though I did not make that clear.

The psiphon website, on the other hand, http://psiphon.civisec.org/
has been blocked, at least by my ISP in Beijing, but the psiphon
service has not been and most likely could not be effectively blocked
without blocking all encrypted tunnels since the IP addresses of
psiphon servers do not have to be publicly known. Tor on the other
hand could be blocked without blocking encrypted tunnels by simply
blocking the IP addresses of Tor servers, since the IP addresses of
Tor servers are and essentially must be publicly known, and
furthermore this is exactly how websites are currently being blocked
in China, ie., the IP address of the server they are hosted on is
blocked. So from the point of view of the Chinese firewall, there
really would be no difference between blocking an IP address serving
up a website and blocking an IP address routing Tor requests.

I think it is very interesting in and of itself that the main Tor
website http://tor.eff.org/ has not been blocked. Perhaps it's the
Great Firewall's way of saying, "We are knowingly allowing this
backdoor."

Kevin S.

On 1/15/07, John Kimble <det.j.kimble at gmail.com> wrote:
> On 1/14/07, Kevin Smith <kevin.in.china at gmail.com> wrote:
> > Why hasn't Tor been blocked in China already?
> >
> It depends on what you're referring to - the Tor website, or the Tor
> service itself.
>
> As far as I know, URLs under http://tor.eff.org/ are blocked, just
> like http://psiphon.civisec.org/ and http://www.torrify.com/ . There
> may be inter-province or even inter-ISP differences though.
>
> If you're referring to the services themselves, neither (Tor or
> Psiphon) are blocked. If you can get Tor (or Torpark for that matter)
> to initialise in the first place, or if you already have someone on
> the outside offering you a Psiphon link, they will just keep running.
>
> I guess that's because China is, for now, focusing solely on blocking
> websites (i.e. readable material served over HTTP). They haven't
> started worrying about encrypted tunnels yet.
>
> - John
>