APPARATUS AND METHOD FOR CONDITIONAL ACCESS OF TERRESTRIAL DMB SERVICE

摘要

An apparatus and a method for conditional access of a terrestrial DMB(Digital Multimedia Broadcasting) service are provided to supply a conditional access service in a shared scrambling manner by receiving ensemble data where many programs are hierarchically mixed, selecting a certain program and scrambling the ensemble data in a manner suitable for a hierarchy of the selected program. An ensemble data analyzing part(311) extracts ensemble configuration information by analyzing external ensemble data to which conditional access is not applied, and hierarchically manages program data. A control word generating part(313) generates a control word. A scrambler(314) scrambles a certain program from the ensemble data analyzing part by using the control word. A conditional access data encoding part(321) receives information of a subscriber and a program, the ensemble configuration information and the control word and encodes conditional access data. An ensemble data multiplexing part(315) generates ensemble data by multiplexing scrambled certain program data, unscrambled program data, fast information group data and the conditional access data and modifying a parameter necessary for the conditional access.