An improved key stream generator based on the programmable cellular automata

Abstract

An improved programmable cellular automata (PCA) based key stream generator is proposed which originates from a recently proposed scheme for key stream generators based on the PCA and a read only memory. Cryptographic security examination of the proposed key stream generator is realized through the following two steps. As the first, an equivalent model of the generator is given, and it is shown that the generator is resistant on the known attacks. Than, a novel method for the cryptanalysis, is developed, and it is shown that the generator is not vulnerable on this approach assuming that PCA length is sufficiently large.