In recent years, research on signal and information theory from the electromagnetics viewpoint has drawn significant attention, mostly due to its potential use in various communication technologies such as multiple-input-multiple-output (MIMO) and Reconfigurable Intelligent Surface (RIS). In this paper, we introduce a new attack called controller manipulation attack (CMA) on a RIS assisted communication system between a transmitter and a receiver, and develop mathematical theory for its design and detection. An attacker has the capability to manipulate the RIS controller and modify the phase shift induced by the RIS elements on the incident electromagnetic signal. 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 a number of attack detection models: (i) composite hypothesis testing based attack detection in a given fading block for known channel gains, (ii) quickest detection of CMA in a given fading block for known channel gains, (iii) nonparametric hypothesis test to detect CMA for unknown channel gains over a fading block, and (iv) signal-to-noise-ratio (SNR) moment based detection over possibly multiple fading blocks. In the first case, we show that a simple energy detector is uniformly most powerful (UMP). In the second case, simplification of the standard CUSUM test and its performance bounds are obtained. In the third case, non-parametric Kolmogorov-Smirnov test is further simplified to a simple per-sample double threshold test. The optimal attack against these three detectors are designed via novel optimization formulations and semidefinite relaxation based solutions. In the fourth 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 optimal attack design problem as a linear program. Finally, numerical results demonstrate the efficacy of the proposed schemes.

中文翻译：

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RIS辅助通信控制器操纵攻击的设计与检测


近年来，从电磁学角度对信号和信息论的研究引起了极大的关注，这主要是由于其在多输入多输出（MIMO）和可重构智能表面（RIS）等各种通信技术中的潜在用途。在本文中，我们针对发射器和接收器之间的 RIS 辅助通信系统引入了一种称为控制器操纵攻击 (CMA) 的新攻击，并为其设计和检测开发了数学理论。攻击者有能力操纵 RIS 控制器并修改 RIS 元件在入射电磁信号上引起的相移。攻击者的目标是最小化接收器处的数据速率，但受到接收器处攻击检测概率的约束。我们考虑了多种攻击检测模型：（i）针对已知信道增益的给定衰落块中基于复合假设检验的攻击检测，（ii）针对已知信道增益的给定衰落块中的 CMA 最快检测，（iii）非参数假设测试以检测衰落块上未知信道增益的 CMA，以及 (iv) 对可能的多个衰落块进行基于信噪比 (SNR) 矩的检测。在第一种情况下，我们证明简单的能量探测器是一致最强大的（UMP）。在第二种情况下，获得了标准 CUSUM 测试的简化及其性能界限。在第三种情况下，非参数 Kolmogorov-Smirnov 检验进一步简化为简单的每样本双阈值检验。针对这三个检测器的最佳攻击是通过新颖的优化公式和基于半定松弛的解决方案来设计的。 在第四种情况下，我们考虑使用SNR矩进行阈值检测；针对大型 RIS，分析获得了无攻击情况下的各种 SNR 矩，然后将其用于将最优攻击设计问题表述为线性程序。最后，数值结果证明了所提出方案的有效性。