Optical image encryption scheme based on random phase mask and phase shift digital holography

Abstract

To improve the security and efficiency of the image message transmission. This paper propose an optical image encryption scheme based on random phase mask and four-step phase shift digital holography. In the process of image encryption, the low frequency sub-band of the original images are superimposed by wavelet transform to increase the encryption efficiency. In this paper, Henon mapping generates two random phase masks. The initial values and control parameters of Henon mapping can be used as the main keys. The use of random phase mask makes the transmission and storage of the keys of sender and receiver more convenient. Moreover, the wavelength and diffraction distance are also used as the keys, which can enhance the security of encryption. With the help of random phase masks and four-step phase-shifting digital holography, the original image is encrypted into four cipher holograms. The simulation results show that the encryption algorithm proposed in this paper can reconstruct high-quality decrypted images and effectively resist various noise attacks.