Storage device, data processing device, registration method, and recording medium

A storage device comprising:

• a switching unit which switches an access destination in a storage area between a first storage area and a second storage area in response to an access request from a host device to which the storage device connects;
• and
• a nonvolatile storage medium which stores a first host device information used to identify the host device in the second storage area, and a software module executed by a CPU provided in the host device, the software module:
• causing the host device to function as a first host device information acquisition unit which acquires the first host device information stored in the second storage area,
• causing the host device to function as a second host device information acquisition unit which acquires from the nonvolatile storage medium a second host device information which identifies a different host device, and
• causing an authority grant unit which transmits a control signal to the switching unit for switching the access destination to the first storage area to the switching unit of the storage device, when the acquired first and second host device information are compared to find that the first and second host device information match with each other.