Mitigation of primary user emulation attacks using belief propagation

Cognitive Radio (CR) is a promising technology that has the potential torevolutionize spectrum utilization by enabling unlicensed users (secondary users) to seek opportunities for transmission by taking advantage of the idle periods of licensed users (primary users) [1]. However, participants in the CR network can comprise of malicious adversaries who adopt dishonest and non-cooperative strategies to attack the network. An attack called the Primary user emulation attack has been identified as the most serious threat to cognitive radio security. In primary user emulation attacks a malicious user emulates the characteristics of a primary user and transmits on available frequency spectrum channels. As a result, secondary users are tricked into believing that the channel is occupied and avoid it, which allows the malicious user to occupy the entire frequency spectrum band uncontested. This report proposes a new technique based on belief propagation to combat primary user emulation attacks in cognitive radio networks. We introduce a method that dramatically reduces the computational complexity and run time of the existing techniques, while also improving the performance.