Attacker-exclusion scheme for cooperative spectrum sensing against SSDF attacks based on accumulated suspicious level

Cooperative spectrum sensing (CSS) is one of the vital mechanisms of cognitive radio (CR), however, its security area has attracted very little attention, which is vulnerable to the attacks of malicious secondary users. To counter the spectrum sensing data falsification (SSDF) attacks, an accumulated suspicious level-based algorithm was proposed. Based on all secondary users' reporting histories, it calculates the accumulated suspicious level and distinguishes honest users and attackers. Then, only the honest secondary users will be incorporated in decision combination at the fusion centre, which improves the robustness of CSS against SSDF attacks. Simulation results illustrated the effectiveness of the proposed scheme. Unlike other existing schemes, the algorithm does not assume any a priori information about the strategy of attackers and can effectively detect the intelligent attackers.