Rail & public transit · Rail Cybersecurity · Signalling Engineering · Safety Assurance
Stage a PKI transition for rail signalling support systems
Which support, management, and communications components can change trust without affecting safe train movement?
Operational pain
Long-lived signalling estates combine safety-certified equipment, vendor maintenance tools, control centres, and telecom links with limited test windows.
Trigger
Certificate expiry, signalling renewal, supplier change, or cryptographic modernization.
QNSI contribution
Connect the decision to a controlled security path
Group certificates, algorithms, issuers, equipment baselines, safety criticality, and maintenance windows in QNSI.
Decision artifact
A signalling-support trust transition plan with lab evidence, rollout cohorts, rollback, and deferred assets.
What still requires validation
The operator and safety authority validate scope, fail-safe behavior, certification impact, test coverage, and operational acceptance.
External problem context
Primary sources
These sources establish the external requirement or risk context. They do not endorse HEOSSI or prove that QNSI completed this scenario.
Evidence boundary
What this page does—and does not—prove
This is a product evaluation pattern, not a customer case study, certification, legal opinion, regulator endorsement, or claim that a production deployment completed the described work.