Double Random Phase Encoding Method Research Articles

Security-enhanced multiple-image encryption based on quick response codes and modified double random phase encoding in the fractional Fourier transform domain.

A security-enhanced multiple-image encryption method is proposed based on quick response (QR) codes and modified double random phase encoding (DRPE) in the fractional Fourier transform (FrFT) domain in this paper, where each plaintext is first converted into QR code, and then each QR code is employed to generate the corresponding binary key for decryption with the help of random binary plaintext (RBP). Subsequently, the used RBP is encrypted into noise-like ciphertext by using the modified DRPE in the FrFT domain. In the modified DRPE method, the first random phase mask is activated by the initial FrFT with chaotic phase, and the wavelength of light and the fractional orders as well as the focal lengths of lenses are all used as digital keys to expand the key space. Moreover, the sensitivities of these digital keys are extremely high because the digital keys are closely mapped with the initial values of the chaotic system in the encryption process, which contributes to an extremely high security of the multiple-image encryption method. Furthermore, the high feasibility and strong robustness of the proposed security-enhanced multiple-image encryption method are also demonstrated by using computational simulations.

Optical color image encryption scheme with a novel DNA encoding algorithm based on a chaotic circuit

An optical setup with a unique color image cryptography technique employing a chaotic system is suggested in this study. For this purpose, deoxyribonucleic acid (DNA) encoding is used as an encryption method. Rössler attractor is employed as a chaotic system and it consists of three differential equations. In order to implement the chaotic system by analog electronic components, a circuit design including operational transconductance amplifier (OTA) is also suggested. Circuit simulations have been performed utilizing LT spice program. In the proposed study, the number of DNA encoding rules has excessively been increased compared to previous studies on DNA encoding technique. Thus, the security of the encryption scheme is enhanced. Numerous security tests such as correlation coefficient, histogram, Shannon entropy, secret key and initial condition sensitivities, plaintext and ciphertext attacks and differential attack have been carried out to evaluate functioning of the introduced cryptography algorithm. The numerical test results prove that the suggested encryption algorithm can resist statistical and differential attacks. Moreover, the cryptology scheme indicates the behavior of sensitivity to initial condition and secret key. The presented algorithm has great performance from the point of encoding rules number and being robust against differential attack. Moreover, enhanced double random phase encoding (DRPE) technique is used in optical stage of the study. By modifying the conventional DRPE method, correlation value between R, G, B components for same pixel have extremely reduced. All numerical analyses regarding chaotic system and encryption scheme have been performed in MATLAB program.

A review of optical image encryption techniques based on Cloud computing biometric and multiple image processing

Cloud Computing technology has become one of the most powerful technologies in terms of high availability, flexibility, and scalability. Besides all the widely perceived benefits of cloud computing, there is a concern that makes the use of the cloud leads to a potential risk that is security. To overcome security issues, a strong authentication mechanism is required. Biometric authentication is one of the very popular methods used for identity detection so that only an authorized person can access the system, one method to achieve this is image processing. In this paper, we review various optical image encryption techniques based on the optical Double Random Phase Encoding (DRPE) system, the oldest and most extensively investigated optical scheme. In the literature, we get an overview of digital image processing applications and data encryption schemes. The various parameter used to measure the image encryption level is discussed. The optical Double Random Phase Encoding method and its numerical simulation are then investigated. In addition to it, other optical encryptions techniques such as multiple image cryptosystem extension and different techniques are discussed that enhance the optical encryption security, which is used widely and generally appreciated. We explored the cloud framework via the biometric authentication process to authorize the legitimate user and permission checks is done by the biometric system. The level of security of the overall system increases when the authorization process is strong and faultless. The challenges faced in this area and the objectives of the research have been discussed.

Double random phase encoding with a Poisson-multinomial distribution for efficient colorful image authentication

In this paper, a new integrated approach is proposed for authenticating digital color image. Here, a new technique, Poisson-Multinomial Distribution (PMD) is introduced for the first time in image processing. It is used for Photon Counting Imaging (PCI) which is integrated with Double Random Phase Encoding (DRPE) scheme in this system. The main goal of this proposal is to establish an image authentication architecture which will only work for 3D digital color images. It is a simplified way for applying PCI scheme on three channels of a 3D image simultaneously. The system will generate a stationary white noise as a final output, which will be difficult to decode for a third party attacker. This proposed scheme works directly with the original digital RGB image. At first, the system encrypts those three channels of the image individually with DRPE method without separating them and the amplitude part of the encrypted image is photon counted using PMD. Finally, to obtain an optimal result, a probability density function is used. On the authentication part, the reference digital image is encrypted by the same keys as the original image and then both of the encrypted images are compared with a statistical nonlinear correlation method. The numerical experiments say that, this proposed PMD based method is proven to be a good and simplified one that can be used to encrypt digital color images. In addition, even if the number of photons is really low, this new system can successfully differentiate between true class and false class images. To prove its efficiency we have also shown some experimental results under different situations.

Optical image encryption technique based on deterministic phase masks

The double-random phase encoding (DRPE) scheme, which is based on a 4f optical correlator system, is considered as a reference for the optical encryption field. We propose a modification of the classical DRPE scheme based on the use of a class of structured phase masks, the deterministic phase masks. In particular, we propose to conduct the encryption process by using two deterministic phase masks, which are built from linear combinations of several subkeys. For the decryption step, the input image is retrieved by using the complex conjugate of the deterministic phase masks, which were set in the encryption process. This concept of structured masks gives rise to encryption–decryption keys which are smaller and more compact than those required in the classical DRPE. In addition, we show that our method significantly improves the tolerance of the DRPE method to shifts of the decrypting phase mask—when no shift is applied, it provides similar performance to the DRPE scheme in terms of encryption–decryption results. This enhanced tolerance to the shift, which is proven by providing numerical simulation results for grayscale and binary images, may relax the rigidity of an encryption–decryption experimental implementation setup. To evaluate the effectiveness of the described method, the mean-square-error and the peak signal-to-noise ratio between the input images and the recovered images are calculated. Different studies based on simulated data are also provided to highlight the suitability and robustness of the method when applied to the image encryption–decryption processes.

Optical encryption with protection against Dirac delta and plain signal attacks.

This Letter proposes an optical encryption technique that disguises the information with modular arithmetic concepts and time-varying noise components that are unknown to the receiver. Optical encryption systems that use these techniques produce a nondeterministic system response, as well as noise like image data that can easily be generated with ordinary spatial light modulators. The principle of this technique is demonstrated for the double random phase encoding (DRPE) method. The conventional DRPE method has major vulnerabilities for Dirac signal and plain signal attacks, making them impractical for secure encryption. It is shown that the proposed encryption technique provides a robustness against these types of attacks, allowing optical DRPE to be employed in secure encryptions. Moreover, applications of this Letter are not limited to DRPE alone but can also be adopted by other optical encryption techniques such as fractional Fourier transform and Fresnel-transform-based techniques.

Fresnel domain nonlinear optical image encryption scheme based on Gerchberg–Saxton phase-retrieval algorithm

We propose a novel nonlinear image-encryption scheme based on a Gerchberg-Saxton (G-S) phase-retrieval algorithm in the Fresnel transform domain. The decryption process can be performed using conventional double random phase encoding (DRPE) architecture. The encryption is realized by applying G-S phase-retrieval algorithm twice, which generates two asymmetric keys from intermediate phases. The asymmetric keys are generated in such a way that decryption is possible optically with a conventional DRPE method. Due to the asymmetric nature of the keys, the proposed encryption process is nonlinear and offers enhanced security. The cryptanalysis has been carried out, which proves the robustness of proposed scheme against known-plaintext, chosen-plaintext, and special attacks. A simple optical setup for decryption has also been suggested. Results of computer simulation support the idea of the proposed cryptosystem.

A review of optical image encryption techniques

In this paper we review a number of optical image encryption techniques proposed in the literature inspired by the architecture of the classic optical Double Random Phase Encoding (DRPE) system. The optical DRPE method and its numerical simulation algorithm are first investigated in relation to the sampling considerations at various stages of the system according to the spreading of the input signal in both the space and spatial frequency domains. Then the several well-known optically inspired encryption techniques are examined and categorized into all optical techniques and image scrambling techniques. Each method is numerically implemented and compared with the optical DRPE scheme, in which random phase diffusers (masks) are applied after different transformations. The optical system used for each method is first illustrated and the corresponding unitary numerical algorithm implementation is then investigated in order to retain the properties of the optical counterpart. The simulation results for the sensitivities of the various encryption keys are presented and the robustness of each method is examined. This overview allows the numerical simulations of the corresponding optical encryption systems, and the extra degree of freedom (keys) provided by different techniques that enhance the optical encryption security, to be generally appreciated and briefly compared and contrasted.

Key management of the double random-phase-encoding method using public-key encryption

Public-key encryption has been used to encode the key of the encryption process. In the proposed technique, an input image has been encrypted by using the double random–phase-encoding method using extended fractional Fourier transform. The key of the encryption process have been encoded by using the Rivest–Shamir–Adelman (RSA) public-key encryption algorithm. The encoded key has then been transmitted to the receiver side along with the encrypted image. In the decryption process, first the encoded key has been decrypted using the secret key and then the encrypted image has been decrypted by using the retrieved key parameters. The proposed technique has advantage over double random-phase-encoding method because the problem associated with the transmission of the key has been eliminated by using public-key encryption. Computer simulation has been carried out to validate the proposed technique.