| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a system has an abnormal operation or is abnormally operated when a file with the program exchanged therein is fraudulently altered, and the original file is not restored after once updated, in a device for controlling the operation of the system, based on the file of a microcomputer. SOLUTION: When the program is updated, the file is updated after confirming whether the file is the fraudulently altered one or not with the use of an electronic signature which is added to the file where the program is converted. The electronic signature is confirmed not in the whole file but only in a specially important part, thereby shortening time to confirm the signature and reducing an area to store a temporary file. Consequently, control is performed to update the program only when the file is the valid one. COPYRIGHT: (C)2009,JPO&INPIT |
