| 摘要 |
<p>Protocol for mutual authentication and for sharing a plurality of encryption keys is practiced between a CPU (12) on a data transmitter (10) side and a CPU (22) on a data receiver (20) side prior to data transmission. The data transmitter (10) encrypts data which requires assurance of a transmission band with a first encryption key by the CPU (12) and transmits it through an input/output interface (16) in a first transmission mode. The data transmitter (10) further encrypts related data concerning the above mentioned data with a second encryption key through the input/output interface (16) in a second transmission mode. The data receiver (20) decrypts the data which requires the assurance of the transmission band and is received through an input/output interface (24) in the first transmission mode with the first code key and decrypts the related data which are received through the input/output interface (24) in the second transmission mode with the second code key.</p> |
