Detection and Performance Analysis of Greedy Individual and Colluding MAC Layer Attackers

Selfish behavior at the Medium Access (MAC) Layer can have devastating side effects on the performance of wireless networks, with effects similar to those of Denial of Service (DoS) attacks. In this paper we consider the problem of misbehavior detection at the MAC layer, focusing on the back-off manipulation by colluding selfish nodes. We cast the problem within a minimax robust detection framework, providing a detection rule of optimum performance for the worst-case attack. We analyze the effects of a single optimal attacker with respect to the detection delay and average number of backoff slots and compare them with the effects of colluding attackers.