Abstract: In a process for the cryptographic processing of data in a cryptographic system, processing takes place in two parts. In the first part the data transmission routines within a data entity and a coded text entity are detected. The clear text and the cryptographic are separately processed cryptographically in the second part and then recombined in the first part with the data transmission routines.

Abstract: A system for inserting extra-information bits into a bit sequence to be transmitted over a transmission channel and for suppressing such bits from the transmitted bit sequence, the system having an inserter at the transmitting end and a suppressor at the receiving end, the inserter converting an input bit sequence which it receives at a first repetition frequency into a second repetition frequency which is higher to correspond to the inserted extra bits, by the insertion of m extra bits per m.k.n bits of the input bit sequence k, n and m denoting integers which are greater than zero, the suppressor restoring the original input bit sequence at the first repetition frequency and the extra-information bits from the output bit sequence which it receives from the transmitter at the second repetition frequency, the inserter comprising a first repetition frequency generator which derives the output bit sequence repetition frequency from the input sequence repetition frequency and complies with the condition n.k.