| 摘要 |
According to the invention digital video, audio and data information can be encrypted according to the MPEG-2 standard either by encrypting the PES packets with an accuracy of a bit or a byte, or by encrypting the transport stream packet with block encryption. Both encryptions can be used in combination. The decryption device in a receiver identifies from the transport stream packet header on which level the encryption is made at the transmitting end, and controls the decryption in accordance with that identification. <IMAGE> |
