Clock-controlled shrinking generator of feedback shift registers

Abstract

A system related to the shrinking generator that is made up of two feedback shift registers in which one (FSR )) controls the clocking of the other (FSR ) is introduced. It is established that if FSR ) generates an m-sequence of period (2m - 1) and FSR generates a de Bruijn sequence of period 2 η, then the output sequence of the system has period P = 2 m+ν-1, linear complexity L bounded from below by 2 m+η-2, good statistical properties, and it is secure against correlation attacks. All these properties make it a suitable crypto-generator for stream cipher applications. © 2003 Springer-Verlag Berlin Heidelberg.