1. In a method for enciphering and deciphering the transmission of data between a transmitter including a code text generator and at least one receiver including a code text generator in which clear text data are linked with key data at the transmitting end and are recovered at the receiving end by linkage with identical key data and in which the same basic key is present in a stored state at the transmitter and at the receiver, each code text generator including a plurality of code text forming registers, the improvement comprising, before the transmission of data: randomly jumbling, in the code text generator at the transmitter, with a fixed or a randomly changing formation rule, at least one code text forming register over a minimum period of time, with a nonperiodic continuous clock pulse which is different from the transmission clock pulse until a random bit sequence of elements has been generated in the code text forming registers; retaining such random bit sequence to define the prime data for the code text generators at the transmitter and at the receiver; transmitting such random bit sequence from the transmitter to the receiver while cyclically shifting the code text forming registers at the transmitter so that after said transmitting, the code text generators at the transmitter and at the receiver have the same prime data, said step of transmitting including transmitting an identifying word indicating start of transmission of the prime data of the code text generators in the transmitter and then transmitting a representation of that prime data in an enciphered form with the basic key which is defined at the transmitter and at the receiver; deriving the formation rule of each code text generator from the random bit sequence generated at the transmitter and transmitted in an enciphered form to the receiver, and during the transmission of data effecting repeated synchronization by temporarily interrupting the flow of data and performing, during such interruption, the steps of: retaining the bit sequence in the code text forming registers of the transmitter at the moment of interruption to define new prime data for the code text generator of each receiver connected to receive such data transmission; or to check the synchronization of such receivers which have synchronized any time before, marking the bit sequence retained at the transmitter at the moment of interruption by an identifying marker, transmitting this bit sequence in enciphered form by means of a basic key information which is identical at the transmitter and the receiver; and deriving the formation rule of each code text generator from the retained bit sequence of the code text forming registers at the transmitter and the receiver.
1. In a method for enciphering and deciphering the transmission of data between a transmitter including a code text generator and at least one receiver including a code text generator in which clear text data are linked with key data at the transmitting end and are recovered at the receiving end by linkage with identical key data and in which the same basic key is present in a stored state at the transmitter and at the receiver, each code text generator including a plurality of code text forming registers, the improvement comprising, before the transmission of data: randomly jumbling, in the code text generator at the transmitter, with a fixed or a randomly changing formation rule, at least one code text forming register over a minimum period of time, with a nonperiodic continuous clock pulse which is different from the transmission clock pulse until a random bit sequence of elements has been generated in the code text forming registers; retaining such random bit sequence to define the prime data for the code text generators at the transmitter and at the receiver; transmitting such random bit sequence from the transmitter to the receiver while cyclically shifting the code text forming registers at the transmitter so that after said transmitting, the code text generators at the transmitter and at the receiver have the same prime data, said step of transmitting including transmitting an identifying word indicating start of transmission of the prime data of the code text generators in the transmitter and then transmitting a representation of that prime data in an enciphered form with the basic key which is defined at the transmitter and at the receiver; deriving the formation rule of each code text generator from the random bit sequence generated at the transmitter and transmitted in an enciphered form to the receiver, and during the transmission of data effecting repeated synchronization by temporarily interrupting the flow of data and performing, during such interruption, the steps of: retaining the bit sequence in the code text forming registers of the transmitter at the moment of interruption to define new prime data for the code text generator of each receiver connected to receive such data transmission; or to check the synchronization of such receivers which have synchronized any time before, marking the bit sequence retained at the transmitter at the moment of interruption by an identifying marker, transmitting this bit sequence in enciphered form by means of a basic key information which is identical at the transmitter and the receiver; and deriving the formation rule of each code text generator from the retained bit sequence of the code text forming registers at the transmitter and the receiver. 2. Method as defined in claim 1 wherein, said step of transmitting a representation is effected with the aid of a lineraly feedback connected shift register whose presetting and/or formation rule depend on the basic key.