ELECTRONIC WATERMARK SYSTEM AND ITS METHOD, AND CONTENTS REDISTRIBUTION SYSTEM AND STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an electronic watermark system and its method, and a contents redistribution system and a storage medium by which the processings required for an author can be completed in the lump on consignment of contents to an agency and to reduce the labor of the author in the case of distribution of the contents. SOLUTION: A feature information extraction function of an agency device 20 extracts feature information I of contents from the contents themselves with respect to the contents G+W(M+Idi) for commissioning sales in the lump from an author device 10. The function transmits the feature information Is with a signature to a user device 30. A feature signature function of the user device 30 applies a signature U to the feature information Is to generate the signal feature information Is U, the agency device 20 imbeds the signed feature information to the contents as electronic watermark information W (Is U) and the obtained contents with an electronic watermark G+W(M+Idi)+W(Is U) are outputted.