| 摘要 |
PROBLEM TO BE SOLVED: To provide a personal identification system and its method in an internet service or the like, making it difficult for an unauthorized user to pose as an authenticated user, and simplifying the system constitution and increasing the convenience of a user. SOLUTION: At executing the personal identification of a user 1 by an internet service or the like, an authenticating server 6 automatically prepares questions (choices) for authentication, based on the information of an electronic mail or the like known only by the user 1, and displays them at a user terminal 2. When the user 1 answers the questions by text work selection of those choices, the authenticating server 6 collates a text keyword stored in a data base as a determining standard, and judges whether or not the user is the person concerned so as to eliminate the need for the user to store an authentication keyword. When the determination of whether or not the user is the person in question is not successful, the authenticating server 6 repeats interactive questions, answers, and determinations until it is successful. The text keyword is stored according to the frequency of generation by collecting and classifying the information of the electronic mail or the like, and then updated in each fixed period, without making the user 1 concious of the keyword. |
