The impact of indirect trust information exchange on network performance and energy consumption in Wireless Sensor Networks

As the applications of Wireless Sensor Networks proliferate, security issues raised in this uncontrolled, self-organised systems comprising a large number of nodes with very low processing, buffering and communication capabilities become mandatory as they need to cooperate with each other, even for routing data messages to the desired destination. A solution that has been widely pursued to detect and avoid nodes that perform denial of service (refuse their forwarding services) is trust management, i.e. each node monitors the forwarding behavior of its neighbours in order to detect any node that behaves selfishly and does not forward the packets it receives. To accelerate trust knowledge gathering, nodes exchange their opinions about their common neighbours. This exchange is beneficial mainly in the case of node mobility. The more often this information is exchanged, the faster the trust information is built. However, as the transmission of this information consumes energy (which is a scarce resource in these settings), there is an interplay between the trust building speed and the energy consumption. This interplay is at the focus of the current paper, which investigates the performance of WSNs using computer simulations.