CONTENT DISTRIBUTION SYSTEM AND DISTRIBUTION METHOD, AND CONTENT PROCESSING DEVICE AND PROCESSING METHOD

摘要

A content distribution system includes a server and a content processing device which are connected to each other via a network. A content distributed by this system is encrypted by using a content key Kc and supplied to a DTV together with a sub license encrypted by a work key Kw. The sub license is formed by a second use condition indicating the condition for use of the content and a content key Kc for decrypting the encrypted content. The work key Kw for decrypting the encrypted sub license is contained in a main license. The main license is supplied to the DTV separately from the content. The main license contains a first use condition indicating the condition for use of the content corresponding to the subscription contract, in addition to the work key Kw. ® KIPO & WIPO 2007