Double image encryption scheme based on known-plaintext attack in fractional fourier transform domain

Abstract

We propose an image encryption scheme based on the double phase encoding in fractional Fourier transform domain for securing two gray-scale images. For encryption, an image to be encrypted is converted into a phase-only image using modified Gerchberg-Saxton algorithm, which serves as a fractional Fourier domain key for encrypting another image employing double random phase encoding framework. For decryption, original images are obtained using the concept of known-plaintext attack. The numerical simulation results are presented in support of the proposed scheme.