communicating between said one receiving terminal and the transmission apparatus via an Internet system, said one receiving terminal being operable to receive a digital broadcasting signal;

receiving authentication data associated with said one receiving terminal;

authenticating said authentication data;

upon authentication, transmitting unique terminal information identifying said one receiving terminal as a destination of transmission and an update program to change the processing of said one receiving terminal, said unique terminal identification information being selected in a manner unrelated to said authentication data and comprising a MAC address of said one receiving terminal, and said transmitting step including converting said unique terminal information into converted unique terminal information comprising a key ID representing an encoded version of said MAC address and transmitting said converted unique terminal information to said one receiving terminal;

storing said transmitted key ID in a first storage location so that it is not recognizable as said encoded version of said MAC address and falsification is preventable;

at said one receiving terminal validating the transmitted key ID to determine whether the transmitted key ID is a legal key ID; and

upon validation:

updating the processing of said one receiving terminal, said updating including receiving at said one receiving terminal said unique terminal information and said update program;

storing said update program in a second storage location;

decoding said transmitted key ID to obtain said MAC address;

upon decoding, storing said MAC address in a location different than said first and second storage locations;

transmitting from said one receiving terminal to said transmission apparatus a transfer request based on said update program and said unique terminal information; and

supplying data responsive to said transfer request from said transmission apparatus to said one receiving terminal based on said unique terminal information.