RAPTor: Routing Attacks on Privacy in Tor

Abstract

Tor is a widely used system that enables Internet anonymity. However, Tor is known to be vulnerable against autonomous systems (ASes) that can observe a Tor user’s traffic between the Tor client and guard relay and also between the exit relay and destination. In this paper, we show that these attacks are just the tip of the iceberg. We present RAPTor, a new set of attacks on Tor that leverage the asymmetric and dynamic nature of Internet paths. Furthermore, we have built a Tor Path Simulation System that quantifies the impact of RAPTor on Tor security and a Traceroute Monitoring Framework that detects and analyzes RAPTor. On a whole, our work highlights the dangers of abstracting network routing in analyzing the security of anonymity systems.