Defense against PUEA and SSDF attacks in cognitive radio networks

Secondary users can utilize the spectrum in the absence of primary users (PU) in cognitive radio networks (CRN). Hence there is a need to sense the spectrum perfectly. Because of hidden node problem, the sensing information given by single SU may not be reliable information. In cooperative spectrum sensing, local sensing is performed by number of SUs and report their local decisions to fusion center (FC). FC combines these local decisions using fusion rules and takes accurate final decision regarding the presence or absence of PU. Primary user emulation attack (PUEA) and spectrum sensing data falsification attack (SSDF) are the two common threats to CRNs. In this paper hard decision fusion rules are applied such as AND, OR and K out of N rules in the presence of PUEA attacker to evaluate the performance of CRN. Also to mitigate the effect of SSDF attack, a novel reputation based method is proposed and these fusion rules are used to make final decision. Energy detection technique is used for local sensing. Simulation results show that the proposed method yields better performance in the presence of PUEA and SSDF attacks.