A new cell counter based attack against tor

Various low-latency anonymous communication systems such as Tor and Anoymizer have been designed to provide anonymity service for users. In order to hide the communication of users, many anonymity systems pack the application data into equal-sized cells (e.g., 512 bytes for Tor, a known realworld, circuit-based low-latency anonymous communication network). In this paper, we investigate a new cell counter based attack against Tor, which allows the attacker to confirm anonymous communication relationship among users very quickly. In this attack, by marginally varying the counter of cells in the target traffic at the malicious exit onion router, the attacker can embed a secret signal into the variation of cell counter of the target traffic. The embedded signal will be carried along with the target traffic and arrive at the malicious entry onion router. Then an accomplice of the attacker at the malicious entry onion router will detect the embedded signal based on the received cells and c...

• Type: Conference
• Year: 2009
• Where: CCS
• Authors: Zhen Ling, Junzhou Luo, Wei Yu, Xinwen Fu, Dong Xuan, Weijia Jia
• Keywords: CCS 2009, Low-latency Anonymous Communication, Malicious Entry Onion, Onion Router, Security Privacy