With respect to encrypted content 104 stored in content storage medium 102, by storing information with a small data amount related to the encrypted content 104 in content storage medium 102 in association with the encrypted content 104, it is possible to distinguish between encrypted content 104 based...http://www.google.fr/patents/US20060069925?utm_source=gb-gplus-shareBrevet US20060069925 - Content processing device, content accumulation medium, content processing method and content processing program
