Message splitting against the partial adversary

Abstract

We review threat models used in the evaluation of anonymity systems' vulnerability to traffic analysis. We then suggest that, under the partial adversary model, if multiple packets have to be sent through these systems, more anonymity can be achieved if senders route the packets via different paths. This is in contrast to the normal technique of using the same path for them all. We comment on the implications of this for message-based and connection-based anonymity systems. We then proceed to examine the only remaining traffic analysis attack - one which considers the entire system as a black box. We show that it is more difficult to execute than the literature suggests, and attempt to empirically estimate the parameters of the Mixmaster and the Mixminion systems needed in order to successfully execute the attack. © Springer-Verlag Berlin Heidelberg 2006.