Securing images using robust chaos based masking and scrambling in the fractional Fourier domain

Abstract

In this paper, we present a robust and secure image encryption scheme that comprises of two major steps of masking of image pixels using piecewise nonlinear chaotic map and scrambling using the chaotic standard map in the fractional Fourier transform domain. The proposed scheme possesses features of both optical signal processing (fast and parallelism) as well as excellent nonlinear confusion and diffusion (due to the use of robust chaos) as desired in an ideal encryption system. The initial conditions and parameters of chaotic maps and the orders of fractional Fourier transform together constitute the secret key. The performance analysis results show that the proposed image encryption scheme is robust and usable in the real-time image and video transmissions.