On the Use of Cellular Automata in Symmetric Cryptography

TL;DR

This paper models nonlinear pseudorandom sequence generators used in cryptography as linear cellular automata, enabling cryptanalysis of their weaknesses and highlighting the vulnerability of such models in stream cipher security.

Contribution

It introduces a simple method to linearize nonlinear generators using cellular automata, facilitating cryptanalytic attacks on stream cipher generators.

Findings

Linear cellular automata can effectively model certain pseudorandom generators.

Cryptanalytic attacks exploiting this model reveal potential vulnerabilities.

The approach demonstrates the ease of analyzing automata-based cryptographic sequences.

Abstract

In this work, pseudorandom sequence generators based on finite fields have been analyzed from the point of view of their cryptographic application. In fact, a class of nonlinear sequence generators has been modelled in terms of linear cellular automata. The algorithm that converts the given generator into a linear model based on automata is very simple and is based on the concatenation of a basic structure. Once the generator has been linearized, a cryptanalytic attack that exploits the weaknesses of such a model has been developed. Linear cellular structures easily model sequence generators with application in stream cipher cryptography.