A Location and Optimal Coverage Based Filtering Scheme in Wireless Sensor Networks

Injected false reports by attackers bring fateful consequences in wireless sensor networks, i.e., wasting the limited batteries of nodes and misleading the decision making of users. Existing security designs mainly attach some extra fields by a group of sensing nodes after the pure data, and check the correctness of attached MACs (Message Authentication Codes) in the process of report forwarding, each of which represents the agreement of sensors on the report, thus to drop the ones which failed on MAC checking. They cannot recognize the reports forged by t arbitrary compromised sensors collaboratively; the variable t is a security parameter. Furthermore, failures of reporting usually occur in sparse regions for lacking of enough detecting sensors, which is incurred by the complicated deploying region and the adopted random deploying strategy. This paper proposes a Location and Optimal Coverage based Filtering scheme (LOCF). It first derived the optimal coverage degree Δ by considering both the network size and covering efficiency, and then employed covering algorithm to deploy sensors accordingly. Each deployed sensor has to dispense its location to downstream sensors, through which sensors are bounded with locations. A report for the observed event must attach t endorsements along with locations of detecting sensors. In the forwarding process, intermediate sensors evaluate the correctness and rationality of both MACs and locations. Simulation results demonstrate that LOCF outperforms existing works in terms of covering effectiveness, filtering efficiency and compromise robustness.