A clock-controlled stream cipher with dual mode

Abstract

In this paper, a new type of clock-controlled stream cipher referred as CCDM (clock-controlled stream cipher with dual mode) is proposed. This model uses five linear feedback shift registers (LFSRs) and has two different clocking mechanisms that provide security enhancements, especially against guess and determine type of attacks, compared to conventional LFSR-based stream generators. Besides its security power against some well-known attacks, the cipher also generates keystream sequences with nice statistical properties.