Vulnerabilities, Attacks, and Countermeasures in Balise-Based Train Control Systems

In modern rail transport systems, balises are widely used to exchange track–train information via air-gap interface. In this paper, we first present the vulnerabilities on the standard balise air-gap interface, and then conduct vulnerability simulations using the system parameters that were specified in the European Train Control System. The simulation results show that the vulnerabilities can be exploited to launch effective and practical attacks, which could lead to catastrophic consequences, such as train derailment or collision. To mitigate the vulnerabilities and attacks, we propose to implement a challenge–response authentication process in the air-gap interface in the existing transport infrastructure.