DATA TRANSMISSION METHOD, AND ELECTRONIC APPARATUS

PROBLEM TO BE SOLVED: To provide a technology of safely transmitting data over the Internet, to an electronic apparatus without having a communication function to the Internet, in relation to a data transmission method. SOLUTION: An apparatus vendor previously registers an apparatus public key certificate 100, an apparatus secret key 102, and an apparatus vendor public key certificate 300 before delivering an electronic apparatus 10. In transmitting data, the electronic apparatus 10 transmits the kept apparatus public key certificate 100 to an apparatus vendor device 30 via a host 20. The apparatus vendor device 30 verifies the apparatus public key certificate 100, encrypts the data to be transmitted by using an apparatus public key 101 if the apparatus public key certificate 100 is issued by itself, signs by an apparatus vendor secret key 302, and transmits the data to the apparatus 10 via the host 20. The electronic apparatus 10 checks a signature attached to the data against a kept apparatus vendor public key 301, and decrypts the transmitted data with a kept apparatus secret key 102 if the signature is justified. COPYRIGHT: (C)2009,JPO&INPIT