Secure Virtual Backbone-Based Power Management for Ad Hoc Networks

Power saving is a critical issue in wireless ad hoc networks. Many of the existing energy efficient routing protocols utilize the power management feature provided by MAC layer (e.g. IEEE 802.11 PSM). The rationale behind these protocols is to power down (put in sleep) the redundant nodes that do not involve in the packets routing. To keep a low end-to-end latency and preserve the routing fidelity, a group of nodes are selected to constitute a virtual backbone throughout the network. The backbone nodes do not sleep all the time serving for the packets routing while the rest of nodes turn to sleep mode if there is no packet to send or receive. Backbone nodes are periodically selected and replaced; the current selection and replacement mechanism mainly concerns the energy balance and fairness among the network nodes while the security threat is not considered. In this paper, we present that the adversary may launch security attacks against the network by exploiting the vulnerabilities of the backbone node selection algorithm. To address this problem, we propose a biased random selection algorithm to prevent the security attacks. The evaluation results indicate that with the aid of reputation system, the proposed biased random selection scheme is more secure than the random selection scheme while trading for a limited amount of power efficiency.