抄録
Digital Broadcasting using Metadata (DBM) is a term describing new broadcasting services offered by utilizing a receiver with storage capacity. The services include program viewing that does not depend on normal broadcasting hours and highlight viewing that uses program-related information, called metadata. Preventing unauthorized use of stored programs is a critical issue in these services. It is extremely easy to edit programs that the broadcaster requires by using a program usage control mechanism. We propose an advanced Conditional Access System (CAS) for DBM. It achieves a secure environment for content and metadata, by preventing tampering and ensuring that only metadata certificated by the broadcaster can be utilized. We also developed a prototype receiver on a PC and an advanced CAS card on a Java Card to evaluate the system. We confirmed through on the implementation experiment that the CAS could be utilized in broadcasting services..
