Image encryption algorithm based on rear-mountedphase mask and random decomposition

Abstract

To escalate the image encryption a new method has been devised which includes double random phase encoding (DRPE) using rear phase masking and random decomposition (RD) technique stranded on fractional Fourier transform. Here, asymmetric cryptographic system is developed in fractional Fourier transform (FrFT) mode using two random phase masks (RPM) and a rear mounted phase mask. In the projected scheme a colored image is decomposed into R, G and B channels. The amplitude of each channel is normalized, phase encoded and modulated using RPM. The modulated R, G and B channels of the colored image are individually transformed using FrFT to produce corresponding encrypted image. The proposed scheme is authorized on grayscale image also. The norm behind the development of the suggested scheme has been elaborated by carrying out cryptanalysis on system based on the RD. The method helps in escalations of the protection of double random phase encoding by cumulating the key length and the parameter amount, so that it vigorously can be used against various attacks. The forte of the suggested cryptographic system was verified using simulations with MATLAB 7.9.0 (R2008a). The efficiency of the suggested scheme includes the analysis using singular value decomposition (SVD), histogram and correlation coefficient.

Asymmetric cryptosystem with random decomposition using fractional Fourier and Fourier transforms

“…In RD [32][33][34][35] a complex valued function f ( μ, γ) can be decomposed into two complex functions f 1 ( μ, γ) and f 2 ( μ, γ) such that (3) ---------------------------------------------------------------- ------------------------------------------------------------------i a…”

“…In RD-based cryptosystems, masks are not in equal modulus, which prevents the transmission of private key information. By understanding the significance of RD, afterwards numerous cryptosystems based on RD [33][34][35] are performed. In the presented work, we have proposed an asymmetric cryptosystem using random decomposition in Fourier and fractional Fourier transforms.…”

High-security image encryption by multiplexing phase encoding in domains of dual optical transforms

“…These methods belong to linear operations and have potential risks. As a possible scheme to develop a new method, a cascaded encoding structure [22][23][24][25][26] can enhance security in an optical information hiding system.…”