| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology capable of taking countermeasures to illegal login without letting user terminal equipment which tries to perform illegal login know that the illegal login has been detected at a system side.SOLUTION: A user authentication system 4 includes: an authentication processing part 44 for authenticating user terminal equipment 1 on the basis of the identification information and authentication information of a received account; an illegality determination part 48 for detecting the illegality of a login request from the user terminal equipment 1 on the basis of an access history from the user terminal equipment 1; and a response control part 46 for, when the illegality of the login request is not detected, and the user terminal equipment 1 is authorized, allowing the user of the user terminal equipment 1 to perform login to a predetermined account, and for, when the illegality of the login request from the user terminal equipment 1 is detected, allow the user of the user terminal equipment 1 to perform login to a dummy account in accordance with a predetermined condition. |
