Beware Peerguardian , PeerBlock , etc. users , do not rely on anonymity using Tor while on Peerblock Client or else.
On Wed, May 14, 2008 at 03:31:50PM +0200,
Nexus23 Labs. wrote:
Hello, I am Karl from Nexus23 Labs. We conduct research on IP ranges that we prefer not to connect with. You may be familiar with PeerBlock or the IP filtering features available in many P2P clients. I would like to inquire if you and your team could implement a similar feature for Tor clients, allowing users to import an ipfilter.dat or .txt file. This would enable us to ban any IP ranges listed within it.
The Answer :
A) Your tool would not be able to ban the “use” of variousTor nodes in the circuit just by looking at outgoing connections
to the first hop, since the Tor client tunnels into connections from the first hop to the further hops.
So if you want to make statements like “don’t use Germany in the circuit”, a tool that monitors the client’s network won’t be able to do that.
But more importantly,
B) Tor’s anonymity comes from having users blending together by making choices over the same set of data using the same weights.
If a given Tor user started choosing paths differently, he would stand out,and actually get *worse* anonymity.
This particular field of path selection is not well-understood and full of pitfalls that might be extremely bad.
So I would worry that if you provided a feature like this for your users,
it would end up harming them in unpredictable ways.
Hope that helps,
Roger Dingledine
Note :
Obviously you can still load ipfilterX into P2P Clients while on TOR ,
that’s why the two things do use different net protocols .