An Intelligent Reflecting Surface-Based Attack Scheme Against Dual-Functional Radar and Communication Systems

Dual-functional radar and communication (DFRC) system is capable of sensing potential eavesdroppers close to the DFRC base station (BS) and further ensuring secure transmission using physical layer security technologies based on the obtained location information of eavesdroppers. However, such security can be threatened by a malicious intelligent reflecting surface (IRS) that simultaneously changes both radar and communication channels. To reveal this threat, an IRS-based active attack scheme is proposed in this paper under the assumption of a prevalent DFRC framework. In this scheme, the attacker, equipped with a malicious IRS, carefully controls and optimizes the IRS phase shifts in each stage of the DFRC framework to reduce its reflected radar echo power to the BS and/or strength the wiretap link gain for pilot spoofing attack according to the statistical channel state information. Numerical results show that our proposed attack scheme can significantly reduce the secrecy rate of the legitimate user, while avoid being detected by the DFRC BS.