| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce operation necessary for a user to carry out when performing user authentication using his or her own communication instrument. <P>SOLUTION: A user authentication system is constituted such that call sections 4d, 5d, 6d, upon reception of a user ID, acquire a unique ID of a user side communication instrument 11 corresponding to a user ID by using user ID correspondence lists 4b, 5b, 6b, respectively, select one calling number randomly using calling number selection sections 4c, 5c, 6c, respectively, call a predetermined number of times for the unique ID of the user side communication instrument 11 corresponding to the user ID from the selected calling number via system side communication instruments 13, 14, 15. When a callback section 11b of the user side communication instrument 11 calls back on the basis of an instruction by a user 1 after completion of the predetermined number of times of calls, user authentication is performed on the basis of a unique ID for callback received with the call sections 4d, 5d, 6d via the system side communication instruments 13, 14, 15 and a unique ID of a call destination. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
