| 摘要 |
The apparatus includes an encryption device associated with an emitter and a corresponding decryption device at each receiver. The receiver has a main circuit board (323) and a smart card (322) is inserted. If the information on the card agrees with that on the main circuit board, decryption can proceed. The decryption operation is controlled by a microprocessor (310) with a memory (325) storing received image lines. A random generator (318) determines which line is to be decrypted. There is a clock control (317). Image outputs (316) are combined (315) with sound (314) which has been decrypted by inversion (312).
|
