摘要 |
The enciphering device generates an enciphered signal (CF) with high bit-rate from the module-2 sum of the signal to be transmitted (TR) with a pseudorandom sequence of bits (PS) obtained by supplying a pseudorandom generator (5) with keys renewed at brief time intervals. The keys are in turn enciphered and encoded (7, 8) to form an auxiliary channel (PC) with low bit-rate which is aligned with the enciphered signal (CF) to form frames. |