POSITION INFORMATION SERVICE SYSTEM, POSITION INFORMATION USING METHOD IN POSITION INFORMATION SERVICE SYSTEM, SENDING TERMINAL, KEY UPDATE CENTER, AND RECEIVING TERMINAL

摘要

PROBLEM TO BE SOLVED: To provide a position information service system which makes the ID of an originating terminal secret to the outside of an exchange network, provides information at a request from an incoming terminal unlimitedly to a special number and charges the terminal for the information, and prevents position information from being fraudulently altered and data from being unauthorizedly reused. SOLUTION: The originating terminal has position information and a means for ciphering the position information by using a ciphering key, and ciphers the position information by using the ciphering key which is periodically updated (at contract limit time) and sends the ciphered information to a terminating terminal. The incoming terminal has a deciphering key and a means for deciphering the ciphered position information by using the deciphering key, and deciphers the ciphered position information sent from the incoming terminal by using a ciphering key distributed from a key update center when the ciphering key of the originating terminal is updated to obtain the position information.