SCRAMBLE/DESCRAMBLE SYSTEM/METHOD FOR BROADCASTING DATA

摘要

PROBLEM TO BE SOLVED: To permit a reception side to accurately recognize a scramble key to realize descramble by permitting a broadcasting-side to extract the bit string of a prescribed position from an original data packet and to generate the scramble key. SOLUTION: A key number read part 20 selectively reads only a bit in a previously decided position among inputted data blocks. Here, plural values as positions are previously decided. A master key read part 22 inputs the bit string which is read by the read part 20 as a master key number. The read part 22 is provided with ROM storing many scramble master keys identified by the master key numbers. The scramble master key corresponding to the inputted master key number is called out from ROM. The original data packet is scrambled and broadcasted by using the scramble key. Thus, it is not necessary to broadcast special scamble key identification information other than data to be broadcasted.