| 摘要 |
<p>A content providing device (10) for providing a content on a web page creates information for monitoring according to the content of a content file and buries the information in the content file. A content monitoring device (20) acquires the content file to be monitored from the content providing device (10), extracts the information for monitoring, and creates another set of information for monitoring according to the content of the content file. By comparing the sets of information, it is judged whether or not the content file is falsified. Thus the third party other than the content provider monitors the content through a computer network to detect alteration if any.</p> |
