Dynamic feedback arrangement scrambling technique keystream generator

Abstract From the Canadian patent

A keystream generator including at least two feedback shift register structures. Each structure has input intermediate and output stages through which data bits are shifted serially in response to a clock signal a plurality of logic elements respectively located between predetermined pairs of register stages means for feeding the data bit shifted from the output stage into the input stage and into predetermined ones of the logic elements in accordance with a polynomial code. The logic elements process a data bit shifted from the preceding stage with the data bit fedback from the output stage in accordance with the polynomial code for input into the succeeding register stage. The structure …