| 摘要 |
PROBLEM TO BE SOLVED: To provide a simple system for suppressing service use by an illegal user in service providing through a communication network. SOLUTION: A service providing server generates a password, stores them relating the password to a user ID (1201), generates an initial message including the user ID and the password (1202), transmits the initial message to a user client 301 (1203), receives a message including the user ID and the password from the client 301 (1204), collates the received password with the stored password (1205), generates a new password, stores them relating the new password to the user ID when the passwords coincide with each other (1206), generates and transmits a message including the user ID and the password (1207 and 1208) and repeats the process from a step (1204) in which the message is received. Thus, the service use of the illegal user resulting from opening a password, etc., to the illegal user by a legal user is suppressed. |
