| 摘要 |
<p>An authentication terminal device (80) ciphers user identification data predetermined for identifying a user and password data determined in relation to the user identification data by using a cipher key created for each service provision request. Susequently, the authentication terminal device (80) transmits authentication data (CTD) containing the ciphered user identification data and password data and deciphering data (DCD) containing cipher key information reflecting the cipher key. Moreover, a service providing system having an authentication server (10) and a reception terminal device (20) deciphers the ciphered user identification data and password data on the basis of the cipher key information, and collates the deciphered user identification data and the deciphered password data to authenticate the user.</p> |
