Asymmetric color cryptosystem using polarization selective diffractive optical element and structured phase mask

Abstract

A single channel asymmetric color image encryption scheme is proposed that uses an amplitude- and phase- truncation approach with interference of polarized wavefronts. Instead of commonly used random phase masks, wavelength-dependent structured phase masks (SPM) are used in the fractional Fourier transform domain for image encoding. The primary color components bonded with different SPMs are combined into one grayscale image using convolution. We then apply the amplitude and phase truncation to the fractional spectrum, which helps generate unique decryption keys. The encrypted image bonded with a different SPM is then encoded into a polarization selective diffractive optical element. The proposed scheme alleviates the alignment problem of interference and does not need iterative encoding and offers multiple levels of security. The effect of a special attack to the proposed asymmetric cryptosystem has been studied. To measure the effectiveness of the proposed method, we calculated the mean square error between the original and the decrypted images. The computer simulation results support the proposed idea.

An asymmetric color image encryption method by using deduced gyrator transform

“…Abuturab proposed an encryption method based on phase-truncation in the gyrator transform domain [11]. Recently, asymmetric cryptosystems based on phase-truncated Fourier transforms have been found to be vulnerable to special attack [12][13][14]. Subsequently, asymmetric cryptosystems based on phase retrieval algorithms [15,16] have been proposed to resist special attack.…”

Hybrid Color and Grayscale Images Encryption Scheme Based on Quaternion Hartley Transform and Logistic Map in Gyrator Domain

“…A method for securing color image based on the Arnold transform and the gyrator transform is reported in [10]. Based on polarization encoding, Nishchal et al proposed two asymmetric color image cryptosystem techniques [14][15]. Li and Zhao [16] designed a color image encryption based on the fractional HT.…”

Optical color image encryption without information disclosure using phase-truncated Fresnel transform and a random amplitude mask

“…In the technique, the image is encoded into a real-value ciphertext with two public keys and a user is able to retrieve the original image using two private keys. Subsequently, optical color image encryption techniques based on phase-truncated cryptosystem were further developed [19][20][21][22]. Chen et al [19] proposed a color image encryption system based on multiple wavelength and phase-truncated Fresnel transform.…”

“…Chen et al [19] proposed a color image encryption system based on multiple wavelength and phase-truncated Fresnel transform. Rajput et al [20] proposed a color cryptosystem using polarization selective diffractive optical element and structured phase mask. Single-channel color image encryption techniques based on phase truncation operation were also proposed [21,22].…”

“…It was reported that using a decryption key the main information of the original image can be revealed [25]. A risk of information disclosure also exists in the aforementioned encryption systems [19][20][21][22]. This does not imply that the PTFT-based cryptosystems do not work; however the risk of information disclosure has to be eliminated.…”