To prevent unauthorized access to a built-in storage medium irrespective of the type of information.
An HDD 10 has a position detection part 36 for receiving radio waves from GPS satellites to detect the current position of the HDD 10 (computer 40), and a nonvolatile storage part 34 having a position information registration area for registering position information about a usable location of the HDD 10 (computer 40) and an authentication information registration area for registering authentication information. When the computer 40 is powered up, an MPU 30 of the HDD 10 checks whether or not position information is registered in the position information registration area, next if any is registered, causes the position detection part 36 to detect the current position and determines whether or not the current position is the usable location, and upon the input of a request to access a magnetic disk 18, reads/writes from/to the magnetic disk 18 in response to the request if no position information is registered or the current position is the usable location, or returns an error response if the current position is not the usable location.
Kato Kazunori
Katsuichi Nishimoto
Hiroshi Fukuda