Impact of Network Topology on Anonymity and Overhead in Low-Latency Anonymity Networks
Low-latency anonymous communication networks require padding to resist timing analysis attacks, and dependent link padding has been proven to prevent these attacks with minimal overhead. In this paper, the authors consider low-latency anonymity networks that implement dependent link padding, and examine various network topologies. They find that the choice of the topology has an important influence on the padding overhead and the level of anonymity provided, and that Stratified networks offer the best trade-off between them. They show that fully connected network topologies (Free Routes) are impractical when dependent link padding is used, as they suffer from feedback effects that induce disproportionate amounts of padding; and that Cascade topologies have the lowest padding overhead at the cost of poor scalability with respect to anonymity.