Yup, and in the embedded world, they are used to achieve encryption of the OS firmware, thus preventing reverse engineering of the device, protecting IP and securing devices through obscurity.

I'm thinking of enterprise grade networking hardware for example. Their main OS ROM is encrypted and they will refuse to decrypt if the boot process is altered.

There are no real secrets or user data being protected by the encryption. Heck, actual passwords and user configurations can be stored in clear.