ABSTRACT
A nonlinear image encryption and authentication strategy based on phase truncation and reservation (PTR) in cylindrical diffraction domain is proposed. First, the cylindrical diffraction spectrum of the input image is sparsely sampled. Then, its sparse presentation is disintegrated into phase part and real-valued amplitude part with the help of the PTR, both of which are essential for decryption and authentication. The decrypted image reveals little information of the original input image visually. Finally, a nonlinear correlation is resorted to authenticate the decrypted image with the input image. In the proposed strategy, the parameters of cylindrical diffraction are utilized to enhance its security. The cylindrical diffraction has the nonlinear characteristics, while the PTR outputs real-valued cyphertext, which further breaks the linearity. Furthermore, the percentage of extracted pixels in sparse sampling needs not to be identified purposely. Numerical simulations demonstrate the feasibility and effectiveness of the proposed scheme.
Disclosure statement
No potential conflict of interest was reported by the author(s).