Low Latency Anonymity with Mix Rings

We introduce mix rings, a novel peer-to-peer mixnet architecture for anonymity that yields low-latency networking compared to existing mixnet architectures. A mix ring is a cycle of continuous-time mixes that uses carefully coordinated cover traffic and a simple fan-out mechanism to protect the initiator from timing analysis attacks. Key features of the mix ring architecture include decoupling path creation from data transfer, and a mechanism to vary the cover traffic rate over time to prevent bandwidth overuse. We analyze the architecture with respect to other peer-to-peer anonymity systems – onion routing and batching mixnets – and we use simulation to demonstrate performance advantages of nearly 40% over batching mixnets while protecting against a wider variety of adversaries than onion routing.