A Novel Scrambling Method Based on Coupling Mode Switching Strategy for Digital Chaos

Abstract

The dynamical degradation of digital chaos brings serious defects to chaos-based digital systems and greatly restricts its applications. In this paper, we first discuss the integer logistic map (ILM) and calculate its cycle lengths under different precision. Then, a novel scrambling method based on coupling mode switching (CMS) strategy named CMSSM is proposed to enhance the chaotic features of digital chaos. Following the selection principles, we use three coupling mode candidates to construct 3CMSSM. Theoretical analysis shows that the output cycle length of 3CMSSM is three times that of scrambling methods used in single coupling mode (SCM) strategy. Numerical simulations are carried out to demonstrate the desirable statistical and dynamical properties of scrambled ILM. Finally, we design a (pseudo-random number generator) PRNG based on 3CMSSM. Both results of statistical test suites NIST SP800-22 and TestU01 show that the suggested PRNG has highly credible randomness compared to other algorithms.