Improved AACS framework for private digital contents

AACS (Advanced Access Content System) has been developed for preventing the piracy of digital contents using broadcast encryption scheme. AACS distinguishes just privileged devices from revoked devices. However, it isn't sufficient for protecting private digital contents created by general consumers who want to keep their private contents using recordable Medias like DVD. This paper presents an improved AACS framework for private digital contents recorded on Media. The proposed framework additionally guarantees that general consumers can indicate playback devices when they record their own contents on Media so that the only devices can play the contents.