| 摘要 |
<p>It is possible to perform time certification at a low cost while maintaining a high accuracy and a high reliability. In a time stamp server of this embodiment, for example, time is measured in hundred millisecond unit and a time stamp is issued by using the time. However, depending on the certification object, what is important in the time stamp is generally a date and it is considered that alteration of the second needle does not have a substantial adverse affect. Accordingly, in this embodiment, the time measured by the clock in the time stamp server is divided into a first portion of minute and above (year, month, date, minute) and a second portion of second (including units below one second such as millisecond). The first portion is checked by an audit department and the second portion is synchronized with the time distributed by the time distribution department. That is, for the first portion, coincidence with the reference time is checked while the second portion is corrected by the time distributed by the time distribution department.</p> |
