TIME AUDIT SYSTEM AND TIME AUDIT METHOD, EXTERNAL TIME MEASUREMENT DEVICE AND PROGRAM THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a time audit system that ensures the reliability of time ticked by a network information processor inside a firewall.;SOLUTION: When the difference of time measured by an external time measurement device 1 and an internal time measurement device 2 is a predetermined value or smaller, the external time measurement device 1 transmits time audit certificate information to the internal time measurement device 2 by using a serial cable. In this case, the external time measurement device 1 determines to perform time synchronization processing to the internal time measurement device 2 only when receiving the time audit certificate information from a time audit device 4, and only when the same can determine to perform the time synchronization processing, the same performs the time synchronization processing of the internal time measurement device 2 by using the serial cable, and transmits the time audit certificate information to the internal time measurement device 2 by using the serial cable.;COPYRIGHT: (C)2010,JPO&INPIT