| 摘要 |
PROBLEM TO BE SOLVED: To provide a password automatic update system allowing a periodic change of a password without notifying an opposite party about a new password. SOLUTION: A secret key comprising a prescribed digit of numerical string is first generated, an effective period of the password is set, and thereafter, the password is generated by use of a password calculation means generating a pseudo random number from the secret key and the effective period. The generated password is automatically updated simultaneously on a transmission side and on a reception side by newly generating a new password from the secret key and the effective period when the effective period lapses. By setting the effective period as a lapse time from a preset reference day, the pseudo random number different in each the update can be generated. COPYRIGHT: (C)2008,JPO&INPIT |
