Coded useful information transmission method has decoding key supplied via separate communications channel

摘要

The transmission method has the useful information (2,3,4) coded before transmission between a transmitter (1) and a receiver (5) via a communications channel (6), with decoding of the useful information at the receiver via a decoding key (10,11) supplied via a communications channel (13). An Independent claim for a device for reception and decoding of encoded useful information received from a transmission channel is also included.