A Survey on Security in Cognitive Radio Networks

Cognitive radio (CR) has been introduced to accommodate the steady increment in the spectrum demand. In CR networks, unlicensed users, which are referred to as secondary users (SUs), are allowed to dynamically access the frequency bands when licensed users which are referred to as primary users (PUs) are inactive. One important technical area that has received little attention to date in the cognitive radio system is wireless security. New classes of security threats and challenges have been introduced in the cognitive radio systems, and providing strong security may prove to be the most difficult aspect of making cognitive radio a longterm commercially-viable concept. This paper addresses the main challenges, security attacks and their mitigation techniques in cognitive radio networks. The attacks showed are organized based on the protocol layer that an attack is operating on.