Interestingly it is Microsoft who filed a patent for DRM-style locking of AI models to verified devices (published July 2026): https://patentlyze.com/patent/microsoft-drm-ai-models-explai...

AI is actually the perfect use case for homomorphic encryption.

I wonder if this space is explored fully enough at the moment.

Aside from some implementation details, it's conceptually much easier than doing it for a SQL database.