Multiple-image encryption based on phase mask multiplexing in fractional Fourier transform domain

Abstract

A multiple-image encryption scheme is proposed based on the phase retrieval process and phase mask multiplexing in the fractional Fourier transform domain. First, each original gray-scale image is encoded into a phase only function by using the proposed phase retrieval process. Second, all the obtained phase functions are modulated into an interim, which is encrypted into the final ciphertext by using the fractional Fourier transform. From a plaintext image, a group of phase masks is generated in the encryption process. The corresponding decrypted image can be recovered from the ciphertext only with the correct phase mask group in the decryption process. Simulation results show that the proposed phase retrieval process has high convergence speed, and the encryption algorithm can avoid cross-talk; in addition, its encrypted capacity is considerably enhanced.

Multiple-image encryption based on triple interferences for flexibly decrypting high-quality images

“…In this section, simulation comparisons with Liangsheng et al [15], in which a phase retrieval and phase mask multiplexing method is proposed, are discussed. Twenty equal-size images (256 × 256), which are shown in Fig.…”

“…[15], deservedly, there are massive time consumption costs in the encryption process, and the quality of the decrypted image is degraded when compared with the original image. Aiming at solving this problem, we proposed this method.…”

“…[15]. It costs 8.33 s to obtain the final ciphertext Only one instance of the decrypted images from Ref.…”

“…Compared with previous homologous MIE methods, to the best of our knowledge, it is an excellent method for significantly eliminating cross-talk noise without a decryption order. However, since an iterative phase retrieval algorithm was utilized to obtain a POF, time consumption and low-quality decrypted images are the drawbacks [15].…”

Chaotic image encryption using pseudo-random masks and pixel mapping

“…All kinds of security problems about image data have emerged, such as unauthorized access and forgery detection [1,2]. Encrypting an image as text data is the most direct way to protect images.…”