Abstract: A removable memory device includes a memory for storing individual information therein, and a memory manager for protecting the memory when the removable memory device is not connected to a portable terminal device and for allowing access thereto when the removable memory device is connected to the portable terminal. A controller physically part of the removable memory device, is used for detecting an interconnection with the portable terminal device and for controlling the memory manager. The removable memory device protects the individual information stored within it from being illegally used.