Detection of deception attacks in cyber physical systems using signal shaping Part I - Basic Scheme

Improvements to efficiency and flexibility in industry are leading to an increasing number of networked control systems. However, the network communication also arises new security issues. In particular, stealthy integrity attacks can cause costs and even safety issues including personal injuries. The so-called deception attacks are designed with the aim of not being detected by (classical) detection systems. Numerous methods are developed to address the detection of attacks in networked control systems. Often the transmitted signals are preprocessed with additional time variant elements (e.g. permutation matrix). Usually, the use of an attack detection system can easily detected, which gives the attacker the opportunity to prepare a more complex attack. This work presents a combination of measures to achieve protection of confidentiality and detect all commonly considered deception attacks in two parts. The first part presents a novel attack detection scheme for cyber physical systems, called signal shaping. Signal shaping is able to protect confidentiality and to detect most deception attacks types. The scheme consists of additive and multiplicative sensor coding. The efficiency of the proposed scheme is illustrated by numerical examples of detecting the aforementioned attacks. In the second part, two enhancements are realised to improve the protection and enable the schemes to detect all attacks often considered as deception attacks in the literature (linear man-in-the-middle, replay, covert and zero dynamics).