DECENTRALIZATION TYPE COPYRIGHT PROTECTING METHOD, CONTENTS PUBLIC OPENING DEVICE CAPABLE OF USING THE SAME METHOD, AND MONITOR SERVER AND SYSTEM

摘要

PROBLEM TO BE SOLVED: To solve the problem that it is difficult for an individual user to protect the copyright of contents. SOLUTION: An agent program 200 patrols user's open servers to inspect whether or not there are illegally used contents. A user certificate authentication part 80 obtains a user ID from a user certificate stored in a certificate data storage part 50. An electronic watermark extraction part 84 extracts an electronic watermark from open contents data stored in a contents data storage part 54 and obtains the creator ID and use permission information of the contents from the electronic watermark. An illegal use inspection part 86 inspects whether the contents are illegally used by using the user ID, creator ID and use permission information. Once illegal use is detected, information regarding the user ID and contents is stored in an illegal use data storage part 90.