| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect unauthorized use of a system in an early stage, when information necessary to use the system is leaked. <P>SOLUTION: An unauthorized use detection system comprises: an access information management part; a period determination part; a time difference calculation part; and an unauthorized use determination part. When a server is accessed, the access information management part acquires a user identifier, location information of a client device and an access time and associates them with each other to store them. The period determination part determines a determination period based on location information corresponding to a latest access time and location information corresponding to a second latest access time among a plurality of access times corresponding to the user identifier. The time difference calculation part calculates an access time difference which is a difference between the latest access time and the second latest access time. The unauthorized use determination part determines that a system is unauthorizedly used if the access time difference is shorter than the determination period. <P>COPYRIGHT: (C)2013,JPO&INPIT |
