2D-FRFT Based Frequency Shift-Invariant Digital Image Encryption

In this paper, we study the property of frequency shift in two-dimensional Fractional Fourier Transform (2D-FRFT) domain. Based on the mathematical verification and computer simulations, it is demonstrated that the magnitude of reconstruction from phase information satisfies frequency shift-invariant in 2D-FRFT domain, improving the robustness of image encryption. Experiments are implemented to verify the effectiveness of this property against the frequency shift attack in 2D-FRFT domain, improving the robustness of image encryption.