Simple Cellular Automata-Based Linear Models for the Shrinking Generator

TL;DR

This paper explores the relationship between Shrinking Generators and Cellular Automata, showing that certain generators can be modeled as linear cellular automata, which aids in cryptanalysis.

Contribution

It demonstrates the equivalence of Shrinking Generators to linear cellular automata, enabling new cryptanalytic approaches.

Findings

Shrinking Generators can be represented by linear cellular automata.

Cellular automata models facilitate cryptanalysis of keystream generators.

The study highlights the linearity property for cryptanalytic advantages.

Abstract

Structural properties of two well-known families of keystream generators, Shrinking Generators and Cellular Automata, have been analyzed. Emphasis is on the equivalence of the binary sequences obtained from both kinds of generators. In fact, Shrinking Generators (SG) can be identified with a subset of linear Cellular Automata (mainly rule 90, rule 150 or a hybrid combination of both rules). The linearity of these cellular models can be advantageously used in the cryptanalysis of those keystream generators.