Device authentication in a service control system

A device authentication apparatus (30), including: a device identification information acquisition unit (31) configured to acquire identification information specific to a device; a connection protection unit (34) configured to protect a connection with the device; and an identifier generation unit (33) configured to combine all or some of the device-specific identification information, a device identification information type representing a type of the device-specific identification information, and a protection method type representing a type of a protection method used by the connection protection unit (34) to generate an identifier for a pair of the connected device and a connection environment.