| 摘要 |
<p>A cipher communication method includes preparing cipher text data which can be decrypted only by a specific partner device, and performing encryption and decryption processing at high speed with realizing an alternate and mutual authentication. A common key is used as encryption and decryption keys, and these keys (Kab) are prepared using the sender's and recipient's device authentication keys. The cipher text data is transmitted together with the sender device authentication key (Ka). In the recipient, the decryption key (Kab) is prepared using the sender device authentication key (Ka) received from the sender and its own device authentication key (kb) to perform decryption processing. The encryption and decryption keys are prepared anew every transmission and reception processes, thereby the cipher communication can be performed while performing alternate authentication every alternate transmission.</p> |
