FORFARANDE FOR KRYPTERAD OVERFORING AV INFORMATION JEMTE ANORDNING FOR UTFORANDE AV FORFARANDET

A method of, and apparatus for, synchronizing a receiver end-Key Generator with a transmitter end-Key Generator wherein both Key Generators are coupled with a respective counter such that each counter state of each counter characterizes a place or position of the Key pulse chain produced by the associated Key Generator. Each counter state is formed in accordance with a formation principle from the preceding counter state. The counter state of the counter of the transmitter end-Key Generator is transmitted to the receiver end and there compared with the counter state of the counter of the receiver end-Key Generator and whenever there is a difference between both counter states the receiver end-Key Generator stepped forward until the difference is again zero. The receiver end-Key Generator is stepped forward when the determined difference of the counter states is smaller than a threshold value and such Key Generator is stepped forward in jumps which encompass many individual advancing steps whenever the difference of the counter states exceeds the aforesaid threshold value.