Encryption key setting system and method, access point, and authentication code setting system

A system of establishing the encryption key for a wireless LAN, the system is intended to establish an encryption key, which is to be used to encrypt communications data radio transmitted between a point (20) access as a station being retransmission for wireless LAN and a terminal (50) equipped with a device (52) for connecting with the wireless LAN prior to the transmission in said terminal, the system setting said encryption key comprising: a module restriction communication range with paragraph (20) access to restrict scope (MRI) of radio communication between said point (20) of access and said terminal (50) must be smaller than a general scope (AR1 ) communication; and a module setting the encryption key to transmit, while the range of the radio communication is restricted by said restriction module of the communication range, the data encryption key representing the encryption key wirelessly between that point (20) of access and the terminal (50) if the terminal is located within the restricted range (MR1) of radio communication, to set the encryption key, in which the point (20) access includes besides a button (127) actuatable by a user registration to enable restriction module communication range.