FastProbe: Malicious user detection in Cognitive Radio Networks through active transmissions

Sensing white space channels to detect whether a particular channel is free or not is very crucial to the operation of Cognitive Radio Networks (CRNs). Cooperative sensing has been shown to improve the performance of channel sensing. However, cooperative sensing is susceptible to malicious users that may not faithfully follow sensing instructions to save energy and/or time, or to launch denial of service attacks against the network. In this paper, we propose a novel active transmissions based algorithm, FastProbe for detecting malicious users. FastProbe proactively detects malicious users before the CRN causes any interference to the Primary Users. Further, using active transmissions, FastProbe achieves higher detection accuracy while maintaining lower overheads when compared with existing algorithms. Simulations and experiments show that in the presence of malicious nodes operating under 2 different attack models, FastProbe reduces the throughput loss due to sensing by as much as 65% compared to existing algorithms.