Application-level attack against Tor´s hidden service

Tor has become one of the most popular overlay networks for anonymizing TCP traffic. Hidden service provided by Tor allows users to run a TCP server under a pseudonym, and its resources can be accessed without the operator´s real identity being revealed. In this paper, we propose a novel HTTP based application-level attack against Tor´s hidden web service. Under the assumption that the entry of the suspected hidden server´s circuit is occupied, we evaluate the time correlation between the web accessing and the generated traffic in the malicious onion router. Furthermore, we analyze the probability that the malicious onion routers occupy the entry of the hidden server´s circuit when advertise high bandwidth, which is the foundation of our attack. We conducted real-world experiments to evaluate our attack method. The empirical results demonstrate that the hidden service can be effectively and efficiently located.