Communication processing system with multiple data layers for digital television broadcasting

摘要

PCT No. PCT/JP95/02682 Sec. 371 Date Aug. 27, 1996 Sec. 102(e) Date Aug. 27, 1996 PCT Filed Dec. 26, 1995 PCT Pub. No. WO96/20563 PCT Pub. Date Jul. 4, 1996Video signals are encrypted so that only the privileged viewers can watch them. A layer coding unit divides video signals into two layers and encodes each layer. An encrypting unit encrypts the low-quality layer data items according to the setting signal from a secret level setting unit and supplies the encrypted signal to a combining unit. Another encrypting unit encrypts the high-quality layer data items according to the setting signal from a secret level setting unit and supplies the encrypted signal to the combining unit. Ideally the high-quality layer data items are encrypted at a secret level that is higher than the secret level used to encrypt the low-quality layer data items. The synthesized data from the combining unit is converted at a communication modem into communication data, which is transmitted to a reception apparatus.