Countermeasures to security threats/attacks on different protocol layers in cognitive radio networks: An overview

Cognitive Radio (CR) is a revolutionary technology which allows the unlicensed user to co-exist along with licensed user. It complements the wireless device by helping in improving its efficiency, reliability, and speed. New security threats have being lifted along with the understanding of cognitive radio, which thereby degrades the performance of cognitive radio. There has been a remarkable growth in security threats prevailing in CR Network (CRN) and also there countermeasure in the past decade. The main objective of this work is to protect CRN from both malicious user and licensed user. Specifically, we present various countermeasures against all possible attacks and threats in different protocol layers in CRN. The various security approaches on different protocol layers can be summarized as using error correcting codes, spread spectrum techniques, cryptographic algorithms and MAC layer admission control mechanism. With this paper, reader can have a clear idea about various countermeasures against attacks on different protocol layer and also about the research trends in this area.