Thursday, August 15, 2013

SIGCOMM13: Towards Efficient Traffic-analysis Resistant Anonymity Networks

Presented by: Stevens Le Blond

Authors: Stevens Le Blond, David Choffnes, Wenxuan Zhou, Peter Druschel, Hitesh Ballani, Paul Francis

Aqua, a k-anonymity system trumps the existing systems by providing performance guarantees in terms of low latency, high-bandwidth and resistance to traffic analysis. This is achieved by exploiting existing correlations in BitTorrent traffic.

The key feature of Aqua is the use of distinct traffic anonymization techniques at the core and the edges. At the core, payloads are split and sent over multiple paths to reduce the peak payload rate. At the edges, clients with similar traffic patterns are grouped together and forced to transmit at similar rates to realize k-anonymity.

Performance of Aqua was compared with other systems such as constant-rate systems, peer-to-peer systems and broadcast systems. While other systems had more than 80% overhead, Aqua provided bandwidth efficiency with less than 30% overhead. Throttling at the edges in Aqua was only 20%, much lower than 50-80% throttling observed in peer-to-peer and broadcast systems.

Q: Why would you run BitTorrent on top of Tor? Tor is too slow.
A : Tor is slow because there are very few servers hosting the service. We expect to have providers hosting Aqua services. If users are willing to pay for it, we could have a large number of hosts offering better service.