| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a view control function for digital broadcast in the form of software, to provide a decoding processing function in the form of software, and to prevent illegal alterations of decoding processing software, contract reception processing software, and program reception processing software and illegal alterations of contract information and key information. <P>SOLUTION: A limited reception processor stores the decoding processing software, contract reception processing software, and reception decision processing software in a non-secret storage area, and also stores a master key Km in a secret storage area. A secret CPU performs decoding processing and contract reception processing on receiving EMM from outside, and an external CPU performs decoding processing and reception decision processing on receiving ECM from outside, extracts a scramble key Ks to perform descramble processing, and stores hash values previously calculated for the processing software in a non-storage area, and the secret CPU performs hash value decision processing software stored in the secret storage area to decide the processing software. <P>COPYRIGHT: (C)2008,JPO&INPIT |
