Impact of Primary User Emulation Attacks on Dynamic Spectrum Access Networks

Primary user emulation attack (PUEA) is a denial of service (DoS) attack unique to dynamic spectrum access (DSA) networks. While there have been studies in the literature to detect and mitigate PUEA, the impact of PUEA on the performance of secondary networks has seldom been studied. In this paper, we analyze how PUEA affects call dropping and delay in secondary networks carrying both real-time traffic and non-real-time traffic. Numerical results indicate that PUEA can increase the number of dropped calls by up to two orders of magnitude and can increase the mean delay by up to a factor larger than two. We then evaluate the performance of secondary networks that deploy the protocols which we proposed previously to mitigate PUEA. Our protocols reduce the number of dropped calls by up to one order of magnitude. Our protocols are also shown to exhibit almost the same delay performance as that of a system with no PUEA, for low malicious traffic load. When malicious traffic load is high, our protocols provide an improvement on the delay performance by up to 54%.

I. Introduction

Cognitive radio enabled dynamic spectrum access (DSA) networks [1]–[3] allow unlicensed “secondary users” to access the spectrum bands unused by licensed “primary users” to improve spectrum utilization. The secondary users evacuate the spectrum bands upon the return of the primary users. This spectrum etiquette could be exploited by malicious users to mount a DSA specific attack called primary user emulation attack (PUEA) [4]. In such an attack, a set of malicious secondary users transmit signals whose characteristics resemble that of the primary transmitter, misleading the good secondary users to believe that the primary user is active and evacuate the spectrum unnecessarily.