parallel mixing
Efforts to design faster synchronous mix networks have focused on reducing the computational cost of mixing per server. We propose a different approach: our reencryption mixnet allows servers to mix inputs in parallel. The result is a dramatic reduction in overall mixing time for moderate-to-large numbers of servers. As measured in the model we describe, for n inputs and $M$ servers our parallel re encryption mixnet produces output in time at most 2n -- and only around n assuming a majority of honest servers. In contrast, a traditional, sequential, synchronous re-encryption mixnet requires time Mn. Parallel re-encryption mixnets offer security guarantees comparable to those of synchronous mixnets, and in many cases only a slightly weaker guarantee of privacy. Our proposed construction is applicable to many recently proposed re-encryption mixnets, such as those of Furukawa and Sako, Neff, Jakobsson et al., and Golle and Boneh. In practice, parallel mixnets promise a potentially substantial time saving in applications such as anonymous electronic elections.
parallel design synchronization network computation cost server encryption mixnet reduction timing model secure privacy applications practical anonymity parallel execution permutation