SECURITY SYSTEM BASED ON CONDITIONAL ACCESS SYSTEM AND METHOD FOR CONTROLLING CONDITIONAL ACCESS SERVICE

摘要

A security system based on a conditional access system and a method for processing a conditional access service using the same are provided to enable a smart card to check whether a subscriber has permission if the subscriber starts recording, decode an encrypted CW, transmit the decoded CW to a receiver, and generate and store right configuration condition information and a CEK, and transmit a program ID(Identification) and the CEK to the receiver, and enable the receiver to encrypt a recording program using the CEK and store the encrypted recording program with the program ID. A security system includes a transmitter(100), a receiver(200), and a smart card(300). The transmitter generates and outputs an ECM(Entitlement Control Message) or an EMM(Entitlement Management Message), and performs the scrambling of broadcast data through a CW(Control Word) or a CEK(Contents Encryption Key) to output the scrambled broadcast data. The receiver receives, analyzes, and processes the scrambled broadcast data, the ECM, the EMM outputted from the transmitter, performs the descrambling of the scrambled broadcast data with the CW or the decoded CEK to output the descrambled broadcast data to a receiving terminal(500), or encodes and stores the descrambled broadcast data. The smart card includes a code/authentication processor and an entitlement message processor. The code/authentication processor compares the EMM with information about the scrambled broadcast data to determine whether a subscriber has permission to the broadcast data, and decodes the encoded CEK of the EMM and outputs the decoded CEK to the receiver.