| 摘要 |
A system for managing safety characteristics in an audio or video service network is particularly adapted to allow only authorized receivers to receive transmitted signals correctly. To this end, the signals to be transmitted in digital form are encoded, the digital information leaving the encoding stage is cryptographed in using a key k, and both the key and the information referring to the decoding algorithm are sent to the authorized receivers in secret form. At the receiving side, the key k received from the transmitter is decoded and then, the digital signal received is decoded in using the specified algorithm and the decoded key k. <IMAGE> |
