A simple acceptance/rejection criterium for sequence generators in symmetric cryptography

Abstract

A simple method of checking the degree of balancedness in key-stream generators of cryptographic application has been developed. The procedure is based exclusively on the handling of bit-strings by means of logic operations and can be applied to standard generators proposed and published in the open literature (combinational generators, multiple clocking generators, irregularly clocked generators). The requirements of time and memory complexity are negligible. The method here developed is believed to be a first selective criterium for acceptance/rejection of this type of generators with application in symmetric cryptography. © Springer-Verlag Berlin Heidelberg 2005.