Trust establishment in cooperative wireless networks

In cooperative wireless networks, relay nodes are used to improve the channel capacity of the system. However, the presence of malicious relays in the network may severely degrade the performance of the system. More specifically, there exists a possibility that a node refuses to cooperate when it is selected for cooperation or deliberately drop the received packets. Trust establishment is a mechanism to detect misbehaving nodes in a network. In this paper, we propose a trust establishment method for cooperative wireless networks using Bayesian framework. In contrast with previous schemes, this approach takes the channel state information and relay selection policy into account to derive a pure trust value for each relay node. The proposed method can be applied to any system with a general relay selection policy whose decisions in each cooperative transmission are independent of the previous ones. Moreover, it does not impose additional communication overhead on the system as it uses the available information in relay selection procedure.