On PHY-layer security of cognitive radio: Collaborative sensing under malicious attacks

In cognitive radio networks, physical layer spectrum sensing plays a key role in helping cognitive radios adapt to changes in spectrum availability. However, it raises significant security issues at the physical layer as well. In this paper, we investigate collaborative sensing of cognitive radio networks under malicious attacks, and analyze the system performance in a generalized framework. The system design goal is to improve efficiency of spectrum access on a non-interfering basis, which is formulated as a constrained parameter optimization problem. A numerical algorithm is provided to resolve the problem. The system performances are evaluated under various conditions, and discussions are provided to help better understand the effectiveness of the attacks and their countermeasures.