For geographically separated cyber-physical systems, state estimation at a remote monitoring or control site is important to ensure stability and reliability of the system. Often for safety or commercial reasons it is necessary to ensure confidentiality of the process state and control information. A current topic of interest is the private transmission of confidential state information. Many transmission encoding schemes rely on acknowledgments, which may be susceptible to interference from an adversary. We consider a stealthy intruder that selectively blocks acknowledgments allowing an eavesdropper to obtain a reliable state estimate defeating an encoding scheme. We utilize Bayesian Quickest Change Detection techniques to quickly detect online the presence of an intruder at both the remote transmitter and receiver.

翻译：对于地理上分离的网络物理系统,在远程监测或控制站点进行国家估算对于确保系统稳定性和可靠性十分重要,通常出于安全或商业原因,有必要确保过程状态和控制信息的保密性。当前一个令人关注的主题是保密性国家信息的私人传输。许多传输编码计划依赖于承认,这可能会受到对手的干扰。我们认为,隐形入侵者有选择地阻止窃听者获得可靠的国家估算,以挫败编码计划。我们利用巴耶西亚快速变化探测技术快速在远程传输器和接收器上迅速发现入侵者在网上的存在。