When Watchdog Meets Coding II 1

In this paper, we study the problem of misbehavior detection in wireless networks . A commonly adopted approach is to utilize the broadcast nature of the wireless medium and have nodes monitor their neighborhood. We call such nodes the Watchdogs. We propose a lightweight misbehavior detection scheme which integrates the idea of watchdogs and error detection coding. We show that even if the watchdog can only observe a fraction of packets, by choosing the encoder properly, an attacker will be detected with high probability while achieving throughput arbitrarily close to optimal. Such properties reduce the incentive for the attacker to attack. We then consider the problem of locating the misbehaving node and propose a simple protocol, which correctly locates the misbehaving node with high probability. The protocol requires exactly two watchdogs per unreliable relay node.