| 摘要 |
PURPOSE:To prevent software from being invaded by dishonest user by collating the contents of a user's response to an identification(ID) question and diagnosing that the user is a valid user or not based upon the collated contents and a user's response history stored in a response history storing part. CONSTITUTION:The device is provided with a user data base 1, a question generating part 2, a response collating part 3, the response history storing part 4, a user diagnostic part 5, and a using software part 6. One ID question is selected out of plural ones and whether the current user is a valid one or not is decided while referring the validity of the response to the ID question and the response error rate and rejection rate of the user in the past fixed number of responses. Consequently, the increment of the error rate due to user's personal difference can be corrected by increasing a change diagnosing its validity by the repeat of the question and a dishonest user trying in invade the software even after continuously generating errors is completely rejected. |
