On Fri, Aug 23, 2013 at 09:19:32AM +0200, Paul-Olivier Dehaye wrote:
The short summary of the weakness of Tor here:
- We would like the whole protocol to be mixing (to an observer, the
probability of exiting at any node C given entrance at node A is close to 1/N),
Right, you're using terminology and threat models from the mixnet literature. Tor doesn't aim to (and doesn't) defend against that.
You might find the explanation in https://blog.torproject.org/blog/one-cell-enough to be useful. The first trouble with mixing in the Tor environment is that "messages" from each user aren't the same size, and it's really expensive to make them the same size ("round up to the largest expected web browsing session").
Another key point: it's not about the paths inside the network -- it's about the connections from the users to the network, and from the network to the destinations.
That said, for the beginning of your related work, see http://freehaven.net/anonbib/#danezis:pet2003
And for a much later follow-up, see http://freehaven.net/anonbib/#topology-pet2010
--Roger