| 摘要 |
<P>PROBLEM TO BE SOLVED: To issue a time stamp of a right time which has no complex device composition and is free from tampering from the outside. <P>SOLUTION: A time stamp device 10 has first and second oscillation means which create oscillation signals of fixed periods, creates a time for time stamping from the oscillation signal of the first oscillation means, and creates a time for confirmation from the oscillation signal created by the second oscillation means. Then the device sends the time for time stamping created by the first time control means to a time audit station system 70 and receives and holds data of a time audit certification. When a time stamp request is received from a client terminal 80, if a time for time stamping created at the time of request reception is in a valid period obtained from the data of the time audit certification, and if an error between the time for time stamping and the time for confirmation is smaller than a prescribed value, the device issues the time stamp data based on the time for time stamping. <P>COPYRIGHT: (C)2009,JPO&INPIT |
