Paper 2002/095

The (a, b)-Shrinking Generator

Ali Adel Kanso

Abstract

A new construction of a pseudorandom generator based on a simple combination of two LFSRs is introduced. This construction allows users to generate a large family of sequences using the same initial states and the same characteristic feedback polynomials of the two combined LFSRs. The construction is related to the so-called shrinking generator that is a special case of this construction. The construction has attractive properties such as exponential period, exponential linear complexity, good statistical properties and security against correlation attacks. All these properties make it a suitable crypto-generator for stream cipher applications.