Re: The use of malicious botnets to disrupt The Onion Router

[Michael Rogers <m.rogers@xxxxxxxxxxxx>]

Andrew wrote:
> Is there anyone who could give a (somewhat professional) assessment of 
> how a web-of-trust feature would impact on anonymity? How about tor's 
> overall performance?

George Danezis has looked at using sparse expander graphs for mix 
networks [1]: each node has a small number of neighbours but can reach 
any other node in a small number of hops, so if the circuit is long 
enough the entry node can't narrow down the list of possible exit nodes 
or vice versa. Unlike Tor, the small number of neighbours per node makes 
it possible to provide cover traffic.

It's not clear whether social networks are good expanders [2][3], but 
Shishir Nagaraja has looked at using social networks for mix networks 
[4]; the LiveJournal social network appears to be suitable, although you 
have to use more cover traffic than you would in an ideal expander graph.

Cheers,
Michael

[1] http://homes.esat.kuleuven.be/~gdanezis/ExpMix.pdf
[2] http://gladiator.ncsa.uiuc.edu/PDFs/networks/barrett2004.pdf
[3] http://www.iop.org/EJ/abstract/0295-5075/73/4/649
[4] http://www.cl.cam.ac.uk/~sn275/papers/unstructured-mixes.pdf