COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a communication system capable of more surely preventing communication with an unfair external network. SOLUTION: According to this system, a database 11 manages a password (p). A first processing means 12 generates a random number Nd according to trigger data received from a terminal 20 and cipher data (first data) of the Nd by (p). A second processing means 13 enables the terminal 20 to generate a random number Nd' by composition of a first data taking a password p' input by an arbitrary user by transmitting the first data to the terminal 20. An authentication means 14 receives cipher data (second data) of the random number Nd' taking the password p' as a key, and authorizes the terminal 20 or not according to the determination on whether the decode data of the second data taking the password (p) as a key and the random number Nd are the same or not. A communication control means 15 controls the communication between the terminal 20 and the external network 40 according to the authentication result of the authentication means 14.