| 摘要 |
PROBLEM TO BE SOLVED: To use a time certificate by a time stamp server while reducing the frequency of connection to a network. SOLUTION: A driver recorder 6 photographs moving images, stores the moving images of prescribed recording time while updating them, also samples and stores still images configuring the moving images, and regarding the still image at the start of sampling, calculates the hash value and transmits it to a server 3 for the hash value. After transmitting the first hash value, the hash value of the still image is calculated every time of sampling the still image, a hash link with the hash value of the still image immediately before is calculated and the hash values are sequentially related. When an event such as an accident occurs, the updating of the moving images is stopped, the included moving image when the event occurs is stored, the hash value of the still image configuring the moving image is calculated, the hash link with the hash value of the still image immediately before is calculated, and the calculated value is transmitted to the server 3 for the hash value. COPYRIGHT: (C)2010,JPO&INPIT |
