Abstract: For the transmission of information, such as voice and data that it is necessary to keep secret, it is standard to encode the information at the transmitting side in the digital level and to in turn decode the encoded information at the receiving side after they have been transmitted. With respect to an economical exploitation of the transmission links, it is standard to combine several signals, or respectively, a plurality of signals on the basis of multiplexing methods. Such digital signal hierarchies are standardized according to the CCITT and, given higher hierarchy levels lead to bit rates of more than 100 Mbit. A solution to the extremely high expense for crypto equipment comprising integrated modules operating at such bit rates, multiplexing technology is employed which makes use of a plurality of encoders and a plurality of decoders that have low power consumption and that are composed of integrated modules constructed in accordance with CMOS technology.

Abstract: In the transmission of information which require secrecy, such as voice and data, serial bit streams having bit rates of more than 100 Mbit can occur, particularly given digital signal hierarchies according to the CCITT recommendations. In order to be able to utilize integrated circuits constructed in CMOS technology having low power consumption for the realization of cryptographic equipment for bit streams having such a high bit rate, it has already been proposed that a plurality of subcoders or, respectively, subdecoders be utilized upon employing multiplexing techniques. Given the utilization of subcoders and subdecoders having the same crypto-codes, a special synchronization between a demultiplexer and a multiplexer at the transmitting side, on the one hand, and at the receiving side, on the other hand, can be foregone given employment of individual synchronization of the subcoders and, respectively, subdecoders assigned to one another at the transmitting side and at the receiving side.