A communication apparatus and a communication processing system incorporating the same, and a digital television broadcasting system (TRANSMITTER. RECEIVER, COMMUNICATION PROCESSING SYSTEM INTEGRATING THEM, AND DIGITAL TELEVISION BROADCASTING SYSTEM)

摘要

The present invention is characterized in that the video signal is encrypted so that it can be viewed only by a privileged person. The hierarchical coding apparatus 5 divides the video signal 3 into two hierarchical levels and encodes each of the hierarchical levels. The encryption apparatus 5 encrypts the low-level data 57 in accordance with the setting signal 63 from the secret-strength setting apparatus 61 and supplies the low-The encryption apparatus 73 encrypts the high-level hierarchical level data 59 according to the setting signal 71 from the secret intensity setting apparatus 69 and supplies it to the synthesizing apparatus 77. [ At this time, the encryption apparatus 73 performs encryption with stronger secret strength than the same apparatus 65. The synthesized data 79 from the synthesizing device 77 is converted by the communication modem 81 to become the communication data 83 and transmitted toward the receiving device.;[Representative figure] Third figure