Transmitter/receiver for signals on the scramble unit

Abstract From the Canadian patent

A pay program signal is scrambled in an exclusive OR circuit by a scrambling signal (Ks) derived from a random number generator. The pay program signal is converted into a broadcasting signal by a converter. A transmission information processor alters every month, for example, the contents of an initial value signal applied to the random number generator in order to change a scramble mode. The information processor transmits via, the converter, cipher signal (Ei) for descrambling the pay program signal in, for example, the next month. The cipher signal (Eil) is stored in RAM of a subscriber. At this time, a memory area into which the cipher signal (Eil) is to be stored is designated by a …