On the Trade-Off Between Security and Energy Efficiency in Cooperative Spectrum Sensing for Cognitive Radio

Cooperative spectrum sensing is envisaged to increase reliability in cognitive radio networks. Several users cooperate to detect the availability of a wireless channel. In this framework, some malicious users may affect the decisions taken by the cognitive users by providing false information, introducing spectrum sensing data falsification (SSDF). In this paper, the effect of multiple malicious users on the energy efficiency of a cognitive radio network is given. A low-overhead security protocol is proposed to address SSDF attacks under a trade-off between energy efficiency and security. An analytical study is provided to set the optimal number of security bits required to maximize energy efficiency. Simulation results show a considerable improvement on the achievable energy efficiency, and the optimal number of bits explicitly depends on the selected fusion rule, the number of malicious users and the number of legitimate users.