  Primary User Emulation Attack (PUEA), in which attackers emulate primary user
signals causing restriction of secondary access on the attacked channels, is a
serious security problem in Cognitive Radio Networks (CRNs). An user performing
a PUEA for selfishly occupying more channels is called a selfish PUEA attacker.
Network managers could adopt a surveillance process on disallowed channels for
identifying illegal channel occupation of selfish PUEA attackers and hence
mitigating selfish PUEA. Determining surveillance strategies, particularly in
multi-channel context, is necessary for ensuring network operation fairness. In
this paper, we formulate a game, called multi-channel surveillance game,
between the selfish attack and the surveillance process in multi-channel CRNs.
The sequence-form representation method is adopted to determine the Nash
Equilibrium (NE) of the game. We show that performing the obtained NE
surveillance strategy significantly mitigates selfish PUEA.
