An entity that has implicitly or explicitly been granted approval to interact with a particular IoT device. The device cybersecurity capabilities in the core baseline do not specify how authorization is implemented for distinguishing authorized and unauthorized entities, but can include identity management and authentication to establish the authorization of entities. It is left to the organization to decide how each device will implement authorization. Also, an entity authorized to interact with an IoT device in one way might not be authorized to interact with the same device in another way.
Source(s):
NISTIR 8259A