Evaluating and Proposal of Over-The-Air Update Architecture For Railway Signalling Applications

Railway control systems increasingly require cybersecurity measures aligned with Industry 4.0 trends and recently published standards such as CLC/TS 50701. Manual software updates in distributed railway networks can cost operators a huge sum deployment cycle due to on-site technician requirements and track downtime, while introducing safety risks during the update cycles that leave systems vulnerable to emerging threats. Over-The-Air (OTA) updates offer a solution, reducing deployment costs and enabling rapid security patch delivery within days rather than months. This thesis comprehensively reviews Public Key Infrastructure (PKI) principles, security protocols, and cybersecurity measures in Linux and Android operating systems. Existing OTA implementations from the automotive industry are analyzed to design a customized OTA architecture for railway signalling systems, including the identification of hardware requirements and security features aligned with CLC/TS 50701 to support a robust and secure framework. The proposed architecture is implemented and validated on a ARM64 hardware, demonstrating successful rollback from corrupted updates within 3 boot cycles and maintaining read-only root filesystem protection throughout the update process.