Engineering Research Center of Metallurgical Automation and Measurement Technology, Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China.
School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China.
Sensors (Basel). 2023 Feb 9;23(4):1957. doi: 10.3390/s23041957.
Stealthy attacks in sensor and actuator loops are the research priorities in the security of cyber-physical systems. Existing attacks define the stealthiness conditions against the Chi-square or Kullback-Leibler divergence detectors and parameterize the attack model based on additive signals. Such conditions ignore the potential anomalies of the vulnerable outputs in the control layer, and the attack sequences need to be generated online, increasing the hardware and software costs. This paper investigates a type of multiplicative attack with essential stealthiness where the employed model is a novel form. The advantage is that the parameters can be designed in a constant form without having to be generated online. An essential stealthiness condition is proposed for the first time and complements the existing ones. Two sufficient conditions for the existence of constant attack matrices are given in the form of theorems, where two methods for decoupling the unknown variables are particularly considered. A quadruple-tank process, an experimental platform for attack and defense, is developed to verify the theoretical results. The experiments indicate that the proposed attack strategy can fulfill both the attack performance and stealthiness conditions.
在网络物理系统安全中，传感器和执行器回路中的隐蔽攻击是研究重点。现有的攻击针对卡方或 Kullback-Leibler 散度检测器定义了隐蔽性条件，并基于附加信号对攻击模型进行参数化。这些条件忽略了控制层中脆弱输出的潜在异常，并且攻击序列需要在线生成，这增加了硬件和软件成本。本文研究了一种具有本质隐蔽性的乘法攻击，所采用的模型是一种新颖的形式。其优势在于参数可以设计成常数形式，而无需在线生成。首次提出了本质隐蔽性条件，并对现有的条件进行了补充。以定理的形式给出了常数攻击矩阵存在的两个充分条件，其中特别考虑了两种解耦未知变量的方法。开发了一个四容水箱过程作为攻击和防御的实验平台，以验证理论结果。实验表明，所提出的攻击策略既能满足攻击性能要求，又能满足隐蔽性条件。
