Using Dust Clouds to Enhance Anonymous Communication (Transcript of Discussion)

This presentation is about dust clouds in third party anonymity, and the fundamental technology that we’re building on is mix networks, which I assume most of you are familiar with. The idea is Alice wants to anonymously communicate with Bob. She does not want to be anonymous to Bob, but wants to be anonymous to some evil Eve that’s observing the network, and to do that she sends her data to a mix network, it goes into hiding from the ingress point to the egress point, and then comes up to Bob, and Eve observing parts of the mix network can’t tell what’s being said or who’s talking to whom, because it all lies encrypted in the network. However, that does not solve the problem if Eve is able to look at both the ingress and egress point of the network, then she can still see what’s going on, so if some evil overlord has a view of the entire Internet (a global passive adversary), we can’t be using a mix network. That’s the basic setting we’re looking at, and the specific mix network that we are concerned with is Tor; we think that our strategy would pretty much work with any mix network, but Tor is the example that we used in the paper.