An identity confirmation method and a identity confirmation system which do not require users to remember passwords, and automatically update credentials for use in identity confirmation, without need for the manipulation by users. This identity confirmation method and system receives current location information from a mobile communication device of a user to accumulates, as a location information history, the current location information of a user. The identity confirmation system generates a question relating to the location information history. The user returns an answer to the question. The identity confirmation system compares and matches the answer with the location information history and determine the identification of the user if the answer coincides with the location information history.