Energy efficient filtering method in sensor networks

Wireless sensor networks (WSN) sense and report interesting events in the sensor field to users. Usually, the sensor field for WSN is hostile and lacks infrastructure, so WSNs are exposed to security threats. In false report injection attacks, attackers inject false reports into the network through compromised nodes. Among many countermeasures to the attacks, the statistical en-route filtering scheme (SEF) detects and drops false reports by collaborative generation and verification of event reports by sensor nodes. In SEF, each node verifies received reports based on a pre-determined probability without consideration of sending nodes, consuming unnecessary energy for report verification. In this paper, we propose an energy-efficient filtering method for sensor networks. In the method, each node controls its verification probabilities for event reports, which depend on sending nodes. The number of recent valid reports and the false traffic ratio of each neighbor node are used to determine the verification probability for each node. We confirmed that our method uses energy efficiently without weakening en-route filtering capability.