| 摘要 |
PROBLEM TO BE SOLVED: To more easily suppress information from being illegally altered in an information storage device.SOLUTION: When a connection object of an information storage device 10 is a legitimate tool, user's operation is needed from a connection of the legitimate tool to transmission of an erasure request signal, so variation in after-connection time from the connection to reception of the erasure request signal is generated. When the connection object of the information storage device 10 is an illegal tool, on the other hand, the after-connection time is always the same since the erasure request signal is automatically transmitted after the illegal tool is connected. A control section 14 can, therefore, determine which of the legitimate tool and illegal tool the connection object is by comparing an after-connection time of each time when the same legitimate or illegal tool is connected to the information storage device 10 twice. When determined to be the illegal tool, the control section 14 restricts erasure of information in a storage section 17. |
