| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technique for encrypting and decrypting a file comprising positional information, preventing access if the file is carried out from a high security area and specifying the physical position of the carried out file by setting up regions permitted to access the file in the file itself. <P>SOLUTION: A GPS function is provided to a terminal unit; the regions which can be used for each file are set up, and software preventing opening of the file except for the set up region is loaded on a terminal. When opening the file, the terminal checks whether or not it is in the designated regions. The positional information of the terminal and the information of the file are stored in the terminal unit and are transmitted to a server at arbitrary timing. By retrieving such information, the operation history of the file can be grasped. Since the place which can be decrypted is set up for each file, a file which can be read only in the physically high security area can be created. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
