On 1/9/2013 4:41 AM, Konstantinos Asimakis wrote:
First of all, AFAIK, bridge relays act as entry guards, meaning they
*replace* the first step of your tor circuits, they don't extend them
to 4 nodes. With that in mind you might be able to do this:
your client -> bridge (obfuscated or not) -> tor node B -> tor node C
-> whatever (clearnet / introduction points for your service)
If you host a hidden service, a compromised bridge on the above
circuit will make you vulnerable to timing attacks whether you
hand-pick trusted nodes for B&C or not.
Also in general when you talk about guard node, you mean a node that
you connect directly too for your first hop on a circuit. It doesn't
make sense to talk about guard nodes in the middle of the circuit, you
don't really care if those are compromised or not since they don't see
you IP.
So another idea would be to use Tor through Tor which
unfortunately doesn't increase your anonymity much since timing
attacks will still work the same way (maybe they will take a little
longer to pull off though but your hidden service will be harder to
reach too).
That being said you can choose your entry guards with the EntryGuards
torrc command and the StrictNodes commands which you can find in the
Tor Manual <https://www.torproject.org/docs/tor-manual.html.en>
If you are super paranoid you could add more latency to the connection
between you and the hidden service server. For example you could rent
a server anonymously in another country to host your hidden service,
and only access that server using Tor from a random public WiFi and
only for short durations (like just reuploading changed html code)
using actually trusted entry nodes. This way even if they manage to
find where the hidden service is located they will have to also start
a separate attack to find where are you connecting to this server
from. And if they find where you do connect from (which will take
considerable time probably) you might have even switched to another
public WiFi by that time. Also who are "they" in this case? Cause we
are talking about an investigation that spans a ton of countries just
to find you. I honestly believe this is overkill. If you need that
much security then maybe Tor isn't for you.
Cheers.
for our purposes, "they" can remain undefined.
there are plenty of "they"s to pick from, what with illegal NSA
wiretapping, various alphabet soup brigades targeting their own
citizens, staggeringly escalated mandatory data retention, new
anti-piracy techniques and legal precedants that allow various copyright
owners to attack their own customers and clients, the list goes on and on.
And that's just the USA. once you include things like
publically-admitted cooperative domestic espionage between allied
countries, and other foreign powers such as China, Russia, North Korea,
and just about every Arab country in existence, there are a multitude of
"they"s to be cautious about.
Though, speaking as someone with an anarchist cypherpunk bent, I don't
really need an excuse to take whatever precautions are available to me,
seeing as any sort of activism or participation in social movements
would cause me to be a political target.
The only reason I'm posting here at all is because I do not think I am
yet a target valuable enough to actually pursue.
When I say "entry guards" i mean entry guards from the perspective of a
tor node acting as a client.
Am i mistaken in believing that a tor bridge relay acts as a client on
behalf of the actual tor client behind it?
Or does the short list of bridge relays act as entry guards, and connect
to other tor relays as the first hop tor relay?
_______________________________________________
tor-relays mailing list
tor-relays@lists.torproject.org
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays
