CONDITIONAL ACCESS SYSTEM FOR DIGITAL DATA BROADCASTING

摘要

A CAS(Conditional Access System) for digital data broadcast for remarkably reducing the burden of data transmission is provided to minimize bandwidth according to EMM. An EMMG(Entitlement Management Message Generator)(40) generates EMM data. An ECMG(Entitlement Control Message Generator)(80) produces ECM data. A CW generator produces a CW(Code Word). A scrambler scrambles broadcast data. The EMMG delivers EMM data to ECMG. The ECMG inserts EMM data within ECM data. The ECMG delivers ECM data in which EMM data is inserted to the scrambler.