| 摘要 |
<p>Television system with a double key: a service key (K) is used for scrambling the transmission and a key (Ci) defines the subscription. For each key (K) corresponds as many messages (Mi) as there are keys (Ci) and these messages are transmitted by a DIDON process to the receivers. The receivers return the service key (K) and unscramble the signals. Application to toll television. </p> |
