# SPD-Safe: Secure Administration of Railway Intelligent Transportation Systems
Cargo and passengers are transported in high volumes each day, covering long distances. In the past, railway accidents have caused a number of deaths, along with significant financial losses [15]. While the introduction of electronic controllers reduced the occurrence of such situations [16], safety risks cannot be ignored, considering the wide railway coverage that still includes aspects such as uninspected car-crossings, system malfunctions (like signal loss), and, of course, the human factor [17; 18]. Within the ever-changing technological landscape, there is currently a move from automated to intelligent cyber-physical systems (CPS), motivated by the speedy infiltration of the Internet of Things (IoT) and cloud computing and enabled by wireless networking [19; 20; 21; 22]. Wireless sensor networks (WSNs) [23] can cover the wide railway operational territory, gathering and processing pieces of ambient knowledge, while gateways can be used to transmit the data to the controlling center or a cloud service. The railway controlling software at the backend can, then, collect and integrate the spatial information and manage the underlying subsystems [24; 25]. Therefore, WSNs are an ideal solution for covering the railway operating area, including the railway routes and various scattered shelters. However, the railway cyber infrastructure and networks currently only adopt rudimentary defenses (e.g., cryptography), which provide protection against the most basic threats, forfeiting effective ways of detecting advanced cyber-attacks [26]. While initially designed as closed systems, current infrastructure networks are vulnerable to various network layer attacks, like blackhole, badmouthing, and jamming attacks [27]. Motivated by the above, this work presents \"SPD-Safe\", (security, privacy, and dependability (SPD)), an administration framework for railway CPS, aiming to enhance the security, privacy, dependability, and safety of the intelligent railway infrastructure, while enabling services for monitoring and managing the overall setting. The framework integrates mechanisms for mitigating cyber-attacks attempting to disrupt communications or compromise infrastructure assets, and periodic malfunctioning of assets is also taken into consideration. SPD-Safe can act as an intelligent communications-based train control (CBTC) system for railway CPS, leveraging artificial intelligence (AI) to manage the system at runtime. The system uses standardized solutions, and its building blocks can be easily retrofitted in current deployments. In addition to the detailed description of the proposed framework, a preliminary implementation is described and evaluated, concentrating on the management of: (a) Incarriage, and (b) on-route sub-systems. WSNs are deployed inside the carriage and by the railway tracks to safeguard carriages that transfer dangerous freight and to help avoid crashes with objects blocking the train's route (like stuck vehicles on rail track crossings), respectively. Furthermore, smart cameras are installed to improve the physical security of the critical infrastructure. In the context of the two use cases (a) and (b) above, through SPD-Safe the railway CPS is configured in real-time to tackle ongoing cyber-attacks and control safety-related incidents. This hands-on validation was developed and demonstrated under the EU-funded project new embedded Systems arcHlecturE for multi-Layer Dependable solutions (nSHIELD) [28], with the cooperation of major industrial partners in the railway and defense domains, including Ansaldo STS ([[http://www.railway-technology.com/contractors/signal/ansaldo-sts/](http://www.railway-technology.com/contractors/signal/ansaldo-sts/)]([http://www.railway-technology.com/contractors/signal/ansaldo-sts/](http://www.railway-technology.com/contractors/signal/ansaldo-sts/))), Selex ES (now LeonardoS.p.A.