Biblio

This paper proposes new concepts for detecting and mitigating cyber attacks on substation automation systems by domain-based cyber-physical security solutions. The proposed methods form the basis of a distributed security domain layer that enables protection devices to collaboratively defend against cyber attacks at substations. The methods utilize protection coordination principles to cross check protection setting changes and can run real-time power system analysis to evaluate the impact of the control commands. The transient fault signature (TFS)-based cross-correlation coefficient algorithm has been proposed to detect the false sampled values data injection attack. The proposed functions were verified in a hardware-in-the-loop (HIL) simulation using commercial relays and a real-time digital simulator (RTDS). Various types of cyber intrusions are tested using this test bed to evaluate the consequences and impacts of cyber attacks to power grid as well as to validate the performance of the proposed research-grade cyber attack mitigation functions.

Intentional electromagnetic interference (IEMI) of information and communication devices is based on high-power electromagnetic environments far exceeding the device immunity to electromagnetic interference. IEMI dramatically alters the electromagnetic environment throughout the device by interfering with the electromagnetic waves inside the device and destroying low-tolerance integrated circuits (ICs) and other elements, thereby reducing the availability of the device. In contrast, in this study, by using a hardware Trojan (HT) that is quickly mountable by physically accessing the devices, to locally weaken the immunity of devices, and then irradiating electromagnetic waves of a specific frequency, only the attack targets are intentionally altered electromagnetically. Therefore, we propose a method that uses these electromagnetic changes to rewrite or generate data and commands handled within devices. Specifically, targeting serial communication systems used inside and outside the devices, the installation of an HT on the communication channel weakens local immunity. This shows that it is possible to generate an electrical signal representing arbitrary data on the communication channel by applying electromagnetic waves of sufficiently small output compared with the conventional IEMI and letting the IC process the data. In addition, we explore methods for countering such attacks.

Networked Control Systems (NCS) are widely used in Industry 4.0 to obtain better management and operational capabilities, as well as to reduce costs. However, despite the benefits provided by NCSs, the integration of communication networks with physical plants can also expose these systems to cyber threats. This work proposes a link monitoring strategy to identify linear time-invariant transfer functions performed by a Man-in-the-Middle during controlled data injection attacks in NCSs. The results demonstrate that the proposed identification scheme provides adequate accuracy when estimating the attack function, and does not interfere in the plant behavior when the system is not under attack.

One challenge for engineered cyber physical systems (CPSs) is the possibility for a malicious intruder to change the data transmitted across the cyber channel as a means to degrade the performance of the physical system. In this paper, we consider a data injection attack on a cyber physical system. We propose a hybrid framework for detecting the presence of an attack and operating the plant in spite of the attack. Our method uses an observer-based detection mechanism and a passivity balance defense framework in the hybrid architecture. By switching the controller, passivity and exponential stability are established under the proposed framework.