| 摘要 |
PROBLEM TO BE SOLVED: To provide a server device which inhibits unauthorized log-in without significantly degrading its usability.SOLUTION: A server device comprises: an information storage unit for storing information; a setting unit for setting a value conversion rule to be applied to log-in authentication; an information generation unit for generating information for the log-in authentication in response to a display request for a log-in screen from a terminal device; a transmission unit for transmitting log-in screen data for displaying the log-in screen, to the terminal device; a reception unit for receiving log-in information from the terminal device; a determination unit for determining whether to authorize the log-in on the basis of the received log-in information; a monitoring unit for monitoring a state of unauthorized log-in to the server device; and a selection unit for selecting a candidate for a new value conversion rule according to the state of the unauthorized log-in. |
