A Trust-Based Technique for Secure Spectrum Access in Cognitive Radio Networks

Cognitive radio networks (CRNs) are becoming an important part of wireless communications, which can improve the utilization of the limited and scarce spectrum resources. However, the flexibility and the unique characteristics of CRN make it vulnerable to varied types of attack. Moreover, security is a key requirement at every step of its functionality (spectrum sensing, spectrum analysis, spectrum decision and spectrum act). Numerous researches have mainly focused on to provide security at the cognition capability (spectrum sensing, spectrum analysis and spectrum decision) of CRN for detecting the appropriate spectrum holes. However, after obtaining access to the spectrum hole (Spectrum Act), a Cognitive Radio (CR) may behave maliciously to achieve own benefits or for some other reasons. Such maliciousness can severely affect the normal activities of the whole network. Therefore, there is a need to track and record the behaviour during the spectrum access of a CR user, which can encourage the CR users to obey the opportunistic spectrum access policy. In this paper, we construct a trust-based approach for secure spectrum access in CRN. The CR nodes trust value is determined from its past activities, and based on which, it is decided whether the CR node will get access the primary users free spectrum or not.