To Örebro University

Direction-of-arrival (DOA) estimation has been widely studied and applied in real-life systems. However, little attention has been given to the risk posed by attackers trying to hide real targets or create fake ones. This poses a serious security and safety concern, as such attacks could lead to system failures or accidents. In this article, we propose DOA spoofing, the first physical layer attack that exploits the semantic gap between DOA estimation outputs and the existing physical location of targets to spoof the perceived sources' location. We consider two scenarios: 1) the attacker wants to create ghost targets at desired locations while being undetected and 2) the attacker wants to change the DOA estimated at the receiver for a target victim. To evaluate the effectiveness of DOA spoofing, we test it against several widely used and well-established DOA estimation algorithms. Via extensive numerical simulations, we demonstrate that in both scenarios, the attacker can spoof DOA estimates at the receiver while not being detected among the targets. To the best of our knowledge, this article presents the first study to examine the impact of DOA attacks on the behavior of radar perception models. Therefore, although not providing a real-life testbed due to the challenges of implementing a noncommercial multiantenna system, our contribution exposes novel threats thanks to the use of algorithms and models commonly used in real-life DOA estimation.