Secure Data Access for Railway Signalling Systems

Rail operators and signalling suppliers increasingly rely on operational data to improve maintenance, optimise performance, and support digital services. At the same time, signalling and trackside systems remain among the most safety-critical and protected environments in railway infrastructure.

The challenge: Extracting valuable data without compromising safety or cybersecurity

Railway systems are undergoing rapid digital transformation. Operators need access to data from signalling systems to enable predictive maintenance, remote monitoring, performance analysis, and other digital services. However, many signalling environments were not designed for external connectivity and must remain isolated to protect safety-critical operations.

This creates a significant challenge. Any connection between signalling systems and external networks introduces potential cybersecurity risks, increases system complexity, and may impact certification requirements.

Organisations therefore face several challenges:

• Limited access to operational data from legacy signalling systems

• Increased complexity when introducing digital services in new projects

• Growing cybersecurity and compliance requirements driven by regulations such as NIS2 and IEC 63452

• The need to maintain strict separation between safety-critical and non-safety systems

The solution: Hardware-enforced one-way data transfer

A data diode provides a completely secure way to extract information from signalling and trackside systems without exposing them to external threats.

By enforcing physical one-way communication, the solution allows operational data to flow from the protected signalling environment to monitoring, analytics, or maintenance platforms, while completely preventing any return traffic. Unlike software-based solutions, data diodes use hardware to make it physically impossible for data to flow back into the OT network, providing an absolute, impenetrable barrier against external attacks. This allows a machine to send out telemetry data without any risk of receiving external commands or attacks if the IT/OT network is compromised.

Key capabilities include:

• Secure extraction of operational and diagnostic data from signalling systems

• Non-intrusive integration with legacy infrastructure without modifying certified systems

• Physical separation between safety-critical and non-safety domains

• Support for remote monitoring, predictive maintenance, and digital services

• Hardware-enforced network segmentation that simplifies compliance and security audits

• Unique and compact form factor 

The solution can be deployed both as a retrofit in existing railway infrastructure and as a standard component in new signalling projects, including ETCS deployments.

The outcome: Safer digitalisation and stronger cyber resilience

By enabling secure access to railway operational data, data diodes help operators and suppliers accelerate digitalisation without increasing cyber risk.

Benefits include:

• Improved visibility into signalling and trackside system performance

• Faster and more effective maintenance through access to operational data

• Simplified integration of digital services in both legacy and modern railway environments

• Stronger compliance with cybersecurity regulations and industry standards

• Reduced attack surface through hardware-enforced network separation

As railways continue to modernise, the ability to securely transfer data from safety-critical systems becomes essential. Data diodes provide a proven and robust approach that enables digital innovation while preserving the integrity, availability, and security of railway operations.