In a method and system for transmitting and receiving data, specified data can be transmitted only to a specific receiving terminal by assigning unique terminal information to the receiving terminal. When transmitted with data, the unique terminal information identifies the specific receiving terminal as the destination of transmission from among a plurality of receiving terminals. An update program for changing the processing of the receiving terminal may be transmitted to the specific receiving terminal along with the unique terminal information. The unique terminal information and the update program are stored in a prescribed storage location in the specific receiving terminal. Thus, a one-to-one broadcasting system is achieved.