Multiplicative cyberattacks manipulating data over the process control system (PCS) communication links are cyberattacks that malicious agents may carry out against PCSs. These attacks are modeled by multiplying the data communicated over the link by a factor, and may be designed to be stealthy without extensive knowledge of process dynamics. The current work characterizes the relationship between the control system parameters, the closed-loop stability, and the detectability of a multiplicative sensor–controller communication link attack with respect to a class of residual-based detection schemes. The analysis reveals that control system parameters may be selected to aid in attack detection. Specifically, control system parameters, called attack-sensitive parameters, may be selected so that the closed-loop process is stable under attack-free operation and is destabilized by a cyberattack, rendering the attack detectable. With the attack-sensitive parameters, however, the attack-free closed-loop process performance may be worse than that with parameters selected based on standard design criteria. To address the potential trade-off between attack-free closed-loop performance and attack detectability, a novel active attack detection methodology utilizing control system parameter switching is developed. The control system switches between the nominal parameters (selected based on standard design criteria) and the attack-sensitive parameters to improve attack detection capabilities while avoiding substantial degradation in the attack-free closed-loop performance. The active detection methodology is applied to an illustrative chemical process example and shown to enhance the attack detection capabilities of two representative residual-based detection schemes.

通过过程控制系统 (PCS) 通信链路操纵数据的多重网络攻击是恶意代理可能对 PCS 进行的网络攻击。这些攻击是通过将通过链路传输的数据乘以一个因子来建模的，并且可能被设计为在没有广泛的过程动态知识的情况下是隐秘的。目前的工作针对一类基于残差的检测方案描述了控制系统参数、闭环稳定性和乘法传感器-控制器通信链路攻击的可检测性之间的关系。分析表明，可以选择控制系统参数来帮助检测攻击。具体来说，控制系统参数，称为攻击敏感参数，可以选择使闭环过程在无攻击操作下保持稳定，并因网络攻击而不稳定，从而使攻击可检测到。然而，使用攻击敏感参数，无攻击闭环过程性能可能比基于标准设计标准选择的参数更差。为了解决无攻击闭环性能和攻击可检测性之间的潜在权衡，开发了一种利用控制系统参数切换的新型主动攻击检测方法。控制系统在标称参数（根据标准设计标准选择）和攻击敏感参数之间切换，以提高攻击检测能力，同时避免无攻击闭环性能的大幅下降。