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Security threat assessment of simultaneous multiple Denial-of-Service attacks in IEEE 802.22 Cognitive Radio networks

The Cognitive Radio (CR) is a fully-reconfigurable wireless device that can intelligently sense, manage, and exploit temporarily-vacant licensed spectrum bands during the absence of incumbent users. Broadly, the IEEE 802.22 is the first complete Wireless Regional Area Network (WRAN) standard that utilizes CR technology in the opportunistic access of white spaces in the television (TV) bands. Intrinsically, the increased CR networks' vulnerabilities alongside the experienced growth of attackers' capabilities, creates a strain on CR network designers to act accordingly. However, most of the existing efforts solely examined the issues of Denial-of-Service (DoS) attacks of IEEE 802.22 networks, such as Primary User Emulation (PUE) attack and Spectrum Sensing Data Falsification (SSDF) attack, each treated in isolation. One main challenge in CR network security domain is to efficiently represent possible simultaneous multiple security threats, and assess their effects. Unlike the previous works, this paper addresses the aforementioned challenge through using the holistic approach of assessing the combined effect of simultaneous multiple DoS attacks. The Bayesian Attack Graph (BAG) model is utilized in this paper to capture the probabilistic dependencies among IEEE 802.22 DoS threat-environment and known vulnerabilities. The simulation results indicate up to 51.3% increase in the probability of DoS in IEEE 802.22 networks considering simultaneous multiple attacks in comparison to the most severe sole attack. Finally, the paper introduces the BAG model as a feasible CR vulnerability metric that can facilitate the creation of a security tightening plan.