The present invention provides a personal authentication method using each individual's characteristics exhibited when entering data from an input device of an electronic computer in a network system, and a program for the personal authentication method, and further a recording medium for the program.To perform personal authentication of a user using an electronic computer by using device actuation characteristics of the user when the user actuates the keyboard, is obtained in a kernel mode that is an operating mode in which all instructions of an operating system are executable, and the actuation time is transmitted to a personal authorizing server by a network system, in the personal authorizing server analyzed to grasp the device actuation characteristics of the user exhibited when actuating the keyboard, and compared the device actuation characteristics with a personal information stored in a database of the personal authorizing server.