Digital signal transmission method e.g. for pay television - having random noise generator transmitting secret key which is applied to form coded text with receiver performing decoding operation using same random noise and key format

摘要

The method involves a transmitter (E1) receiving a random noise generator signal as an input. The random noise is applied to a secret key (KOWF) which provides a one time masking pad. Non-coded text is applied to an XOR gate, with the masking pad, producing coded text sent to the receiver. The receiver (R1) receives the random noise, and passes the noise through an identical secret key to the transmitter. The output masking code is passed to an XOR gate with the coded text to produce a decoded output.