Introduction to Special Issue on Cybersecurity and Resiliency for Transportation Cyber-Physical Systems

Transportation cyber-physical systems (TCPS) utilize computing and communication power to integrate and optimize the movement of goods and people, with the goal of advancing society.Hardware and software within TCPS enable us to store, transfer, process, analyze, and act on huge amounts of data in real time.The potential benefits of such a system transcend the boundaries of social, economic, and environmental domains, which include reduced traffic congestion, delays, crashes, fuel use, emissions, and lowered monetary costs for transportation infrastructure.However, TCPS open unprecedented opportunities for malicious actors to steal data, invade privacy, demand ransom, and generate misinformation.Ultimately, they could even shut down the transportation systems on which our lives, safety, prosperity, and security depend.These attackers may range from individual hackers to criminal gangs, and their impacts on public safety can be disastrous.Attackers could potentially gain access to the control system of TCPS, causing catastrophic multi-vehicle crashes or even holding the authorities to ransom.Moreover, if these systems are spread across various parts of a city, they could potentially shut down the entire transportation network, causing a ripple effect on non-transportation systems in an Internet of Things (IoT) environment.The number of cyberattacks on smart mobility systems has risen significantly worldwide.However, the full extent of cybersecurity threats and their impacts on TCPS remains largely unknown, and there are no clear solutions to mitigate such attacks.The theme of this Special Issue of the ACM Journal on Autonomous Transportation Systems (JATS) is to address the gap through consolidation of innovative security solutions for evolving TCPS.This special issue acts as a nexus, aiming to converge multidisciplinary researchers and experts to present cutting-edge contributions and chart the trajectory of future advancements pertinent to cybersecurity and resiliency of TCPS.Based on peer reviews, six articles have been accepted.Below is a concise overview of the articles featured in this special issue:The first article, "Systematic Risk Characterization of Hardware Threats to Automotive Systems," presents a unique approach to characterizing attacks on hardware components, communication modules, and embedded software in modern automotive systems.This article employs Gajski-Kuhn Y-charts to depict how attacks manipulate these systems across behavioral, structural, and physical domains.The selection of attacks is based on real-world evidence, showcasing threats that have been proven feasible.The impact of these threats is then assessed using the ISO/SAE 21434 standard for automotive cybersecurity risk assessment, which includes potential mitigations.This article offers unique insights into the intricate dynamics of hardware vulnerabilities and how the industry can address system-level security and protection for modern automotive platforms.