| 摘要 |
PURPOSE:To prevent unfair reception of broadcasting programs by temporarily holding contract information stored in an enciphered state after decoding when a desired program is received and canceling the scramble of the program based on the contract information. CONSTITUTION:When an enciphered related information packet is received, the packet is stored in the contract information preserving area 203-a of a RAM in the enciphered state when the information is contract information. When the related information is broadcast information, on the other hand, the information stored in the area 203-a is decoded by using a decoding key Km for contract and temporarily stored in the contract information temporarily storing area 202-a of a register group 202. Then, the broadcast information is decoded by using a decoding key Kw for program held by the area 202-a and stored in a program information preserving area 201-a. Thereafter, the content of the contract information held in the area 202-a is compared with the program watching condition and, when the watching condition is satisfied, the scramble of the program is canceled. |
