ETCS on-line key management, in the open.
The library that carries across kmc-subset137.eu, its search visibility and its community. Its visitors arrive through repositories, forums and citations, and those links will never be updated. The migration is designed around that fact.

What the specification covers.
SUBSET-137 defines on-line key management for ETCS: how the cryptographic keys that authenticate communication between on-board and trackside are generated, distributed, updated and revoked without taking equipment out of service.
An explainer written for someone who has not read the subset is evergreen content and will attract steady search traffic long after any product announcement.
What the library does today.
- SUBSET-137 v1.0.0 implemented
- Evolving to v4.0.0, including SS-146
- Architecture, supported platforms and dependencies documented
- Build and integration instructions published
- Conformance and testing evidence available
Open source, and what sits beside it.
Licence and governance
Licence text, contribution model, release history and versioning policy.
Repository
Unchanged entry point, so existing links and citations keep working.
Commercial support
Maintenance, warranty, certification evidence and response times: the bridge from open source to a customer relationship.
