What is in the standard
This guidance is concerned with protecting rail infrastructure and rolling-stock systems and handling threats and incidents. The Department for Transport (DfT) is looking to encourage the use of the US NIST cybersecurity framework amongst UK companies that operate critical infrastructure. Rail systems are becoming more vulnerable to cyber attack due to the integration of open-platform systems, equipment using COTS components and increased prevalence of control and automation systems that can be accessed remotely via public and private networks. The guidance applies to all rail networks in Great Britain to include high speed heavy rail, conventional heavy rail, London Underground, Docklands Light Railway, Glasgow Subway.
Relationship to Unidirectional Gateways
As signals are of critical importance from a safety perspective, the guidance states that signaling systems on rail networks should contain unidirectional gateways. Train control and signaling – networks for passengers should be physically or electronically separate from networks used for train control and signaling (especially where WiFi is used).
The attack surface of rail networks is rather large due to multiple systems control, signaling, IT and passenger networks. The DfT understands the threat cyber attacks can have on public safety and recommends the strongest technology for its signal systems – unidirectional gateways.