Controller Manipulation Attack on Reconfigurable Intelligent Surface Aided Wireless Communication

In this paper, we introduce a new attack called controller manipulation attack (CMA) on a Reconfigurable Intelligent Surface (RIS) assisted communication system between a transmitter and a receiver. An attacker has the potential to manipulate the RIS controller and modify the phase shift induced by the RIS elements. The goal of the attacker is to minimize the data rate at the receiver, subject to a constraint on the attack detection probability at the receiver. We consider two different attack detection models: (i) composite hypothesis testing based attack detection in a given fading block for known channel gains, and (ii) SNR moment based detection over possibly multiple fading blocks. In the first case, a simple energy detector turns out to be uniformly most powerful (UMP) and the attack against this energy detector is designed via a novel optimization formulation and a semidefinite relaxation based solution. In the second case, we consider threshold detection using moments of SNR; various SNR moments under no attack are obtained analytically for large RIS and then used to formulate the attack design problem as a linear program. Finally, numerical results illustrate the performance and trade-offs associated with the attack schemes, and also demonstrate their efficacy.

OptM3Sec: Optimizing Multicast IRS-Aided Multiantenna DFRC Secrecy Channel with Multiple Eavesdroppers

With the use of common signaling methods for dual-function radar-communications (DFRC) systems, the susceptibility of eavesdropping on messages aimed at legitimate users has worsened. For DFRC systems, the radar target may act as an eavesdropper (ED) that receives a high-energy signal thereby leading to additional challenges. Unlike prior works, we consider a multicast multi-antenna DFRC system with multiple EDs. We then propose a physical layer design approach to maximize the secrecy rate by installing intelligent reflecting surfaces in the radar channels. Our optimization of multiple ED multicast multi-antenna DFRC secrecy rate (OptM3Sec) approach solves this highly nonconvex problem with respect to the precoding matrices. Our numerical experiments demonstrate the feasibility of our algorithm in maximizing the secrecy rate in this DFRC setup.