A Cryptographic and Key Management Glance at Cybersecurity Challenges of the Future European Railway System

In today's globalized economy, the transport of people and goods is essential. Railways form a critical infrastructure that constitutes one of the backbones of modern society. Furthermore, a shift from air and road transport to electric railway enables a cost-efficient reduction of the negative climate impact caused by transport. Thus, the utilization of existing railway systems must become more efficient. Consequently, the importance, complexity, and smartness of these systems increases, but the systems simultaneously become more vulnerable to attacks. Within the European Union, there is a quest for a pan-European standardized control system for railway traffic. Old, national, non-interoperable railway communication systems need renewal. The European Rail Traffic Management System (ERTMS) is the European standard for automatic train protection as well as for command and control systems. The next-generation development effort, the Future Railway Mobile Communication System (FRMCS), builds on a 5G service standard. This article focuses on two key aspects of cybersecurity, namely cryptographic and key management challenges in proposed railway communication systems.