A Novel Gray Image Encryption Algorithm Based on Improved Logistic Chaotic Mapping

In this paper we proposed an improved Logistic chaotic mapping and analyzed chaos characteristic and periodicity of this mapping which was used in gray image encryption.This is a digital image encryption algorithm and dual scrambling that based on chaos of pixel position and pixel value. Compared with the traditional logistic equation, the improved chaotic equation has both chaos characteristic and periodicity, when the number of iterations of the mapping is less than 20,the periodicity of the function is 58;when iterative times are more than 20,the mapping has chaotic characteristic only.Therefore,the improved Logistic mapping has larger key space,and theoretical analyses show that the generated chaotic sequences has excellent performance such as cross correlation and sensitivity.It is shown by Matlab simulations: the results of experiment simulation indicate that the algorithm has more efficiency and security.