Cyber-physical attacks exploit intrinsic natures of physical systems and can severely damage cyber-physical systems (CPSs) without being detected by the conventional anomaly detector. In this article, based on software-defined networking, we propose a holistic resilient CPS framework that can detect, isolate, and recover from cyber-physical attacks in real time. To show the effectiveness of the proposed framework, we focus on the pole-dynamics attack (PDA), a newly reported stealthy sensor attack that can make the physical system unstable. We develop an efficient detection algorithm for PDA and embed it into the proposed framework. By implementing a testbed, we validate that the proposed framework guarantees resilience of CPS against the PDA.

Modern embedded systems are increasingly complex and contain multiple software layers from BSP (Board Support Packages) to OS to middleware to AI (Artificial Intelligence) algorithms like perception and voice recognition. Integrations of inter-layer and intra-layer in embedded systems provide dedicated services such as taking a picture or movie-streaming. Accordingly, it gets more complicated to find out the root cause of a system failure. This industrial proposal describes a difficulty of testing embedded systems, and presents a case study in terms of integration testing.

A cyber-physical system (CPS) is an entanglement of physical and computing systems by real-time information exchange through networking, which can be considered as real-time IoT because of end-to-end real-time performance guarantee. Most societal infrastructures, such as transportation systems, smart power grid, smart factory, and smart buildings, are key application domains of CPS. Though there have been extensive studies on infrastructures from the perspective of cyber security, insufficient research has been conducted from a practical viewpoint of cyber-physical security. In this paper, we focus on train control systems as one of the critical infrastructures. We fully investigate the emerging de facto standard of train control systems, communication-based train control (CBTC). We analyze the cyber-physical vulnerability of CBTC and discover that a man-in-the-middle attack combined with knowledge on train signaling can cause train collisions in CBTC. To resolve the issue, we propose a countermeasure for resiliency of CBTC. By implementing a realistic CBTC testbed, we validate our analysis. To the best of our knowledge, this is the first in-depth empirical study on cyber-physical vulnerability of CBTC systems.