A comparative study on anonymous 802.11n protocols

Many anonymous communication solutions have been proposed to provide anonymous mobile ad hoc network (MANET) communications. However, they mainly focus on the routing layer and above to hide the end-to-end traffic patterns. The point-to-point communication relations are often considered as non-critical information in terms of anonymity, which actually exposes the traffic patterns on the PHY/MAC layer. Adversaries may utilize the MAC layer protocol to derive the end-to-end communication relations by using statistical traffic analysis. Unfortunately, the most popular wireless MAC protocol used in MANETs, i.e., IEEE 802.11, will reveal the point-to-point communication relations to attackers. In this paper, we investigate several solutions to hide the 802.11 point-to-point communication relation. We perform a comparative study to analyze the feasibility of these potential solutions. Our research results indicate that the pure physical carrier sensing approximately archives the similar performance compared to the standard 802.11 protocols, while achieving better point-to-point anonymity.