Spoofing or Jamming: Performance Analysis of a Tactical Cognitive Radio Adversary

The tradeoff between spoofing and jamming a cognitive radio network by an intelligent adversary is analyzed in this paper. Due to the vulnerabilities of spectrum sensing noted in recent studies, a cognitive radio can be attacked during the sensing interval by an adversary who puts spoofing signals in unused bands. Further, once secondary users access unused bands, the adversary can use traditional jamming to interfere with them during transmission. For an energy-constrained intelligent adversary, a two step procedure is formulated to distribute the energy between spoofing and jamming, such that the average sum throughput of the secondary users is minimized. That is, we optimally spoof in the sensing duration and then optimally jam in the transmission slot. In a cluster-based cognitive radio network, when the number of spectral vacancies required by secondary users increases, the optimal attack for the intelligent adversary will shift from jamming only, to a combination of spoofing and jamming, to spoofing only.