Multiple-image Encryption Research Articles

A superposition based multiple-image encryption using Fresnel-Domain high dimension chaotic phase encoding

A new superposition based multiple-image encryption using Fresnel-domain high dimension chaotic phase encoding is proposed. In this method, each color image of an authenticated user is decomposed into R, G, and B channels. The amplitude of each channel is independently normalized, phase encoded and then modulated by corresponding high-dimension chaotic random phase mask (HDCPM). The modulated R, G, and B channels of multiple color images are individually added and Fresnel transformed to produce corresponding encrypted channels. All the parameters (initial values and control parameters) of HDCPM are exploited as remarkably sensitive decryption keys of the proposed system. Moreover, the update, management, and transmission of the decryption keys are convenient. The individual decryption keys of R, G, and B channels significantly increase the resistance to various types of attacks. The proposed cryptosystem can be executed by using a hybrid optoelectronic system. Numerical simulation results demonstrate the viability and effectiveness of the proposed scheme.

A novel multi-dimensional multiple image encryption technique

This paper proposes a novel secure and fast multiple image encryption technique to encrypt multiple images of arbitrary sizes. In the proposed technique, a group of images is divided into non-overlapping blocks of size 2 × 2 pixels. For odd numbered image size, separate 2 × 2 sized blocks are formed from the last row and/or column pixels. The generated blocks and the remaining pixels (if any) are then arranged in separate arrays. Finally, the array of blocks and remaining pixels are separately permuted and diffused using different piece-wise linear chaotic map (PWLCM) systems. The significance of this algorithm is the use of arbitrary sized multiple images to perform multiple image encryptions. Another significance of this algorithm is the use of only PWLCM systems in permutation and diffusion operations to make the algorithm secure and efficient in both software and hardware platforms. The computer simulation reveals the good encryption results of the proposed cryptosystem. The security analysis shows that the proposed method performs better against widely known security attacks.

基于压缩全息和空分复用的多彩色图像加密

基于压缩全息和空分复用的多彩色图像加密

基于光场成像原理和混沌系统的多图像加密方法

基于光场成像原理和混沌系统的多图像加密方法

A Novel and Efficient 3D Multiple Images Encryption Scheme Based on Chaotic Systems and Swapping Operations

Single image encryption schemes are not efficient enough when a bunch of images is to be encrypted in some real-world setting. To overcome this problem, an efficient and secured multiple images encryption scheme is proposed in this study using two chaotic maps and simple row and column swapping operations in a 3D image space. The N input images are piled to make a 3D image. To confuse the given pixel data, two images are chosen randomly from this pile. The randomly chosen two rows from the two randomly chosen images are swapped with each other. In the same way, two randomly chosen columns are swapped with each other. The operation of randomly chosen two images, two rows, and two columns have been iterated an arbitrary number of times to throw the confusion effects in the pixels data. Intertwining Logistic Map (ILM) and Improved Piecewise Linear Chaotic Map (MPWLCM) have been used to get the four streams of random numbers. The three streams of the former map have been used to create the confusion effects, whereas the fourth stream of random numbers given by the latter map has been used for the diffusion effects. SHA-256 hash codes have been used to throw the plaintext sensitivity in the proposed cipher. Besides, a 256-bit user key has been employed to increase the key space. Both the simulation and the exhaustive security analyses carried out at the end vividly prove the security, resistance to the varied attacks, and the real-world applicability of the proposed cipher.

Multiple image encryption of high robustness in gyrator transform domain

Multiple image encryption of high robustness in gyrator transform domain

基于图像重组和比特置乱的多图像加密

基于图像重组和比特置乱的多图像加密

Single-shot optical multiple-image encryption by jointly using wavelength multiplexing and position multiplexing.

A single shot large-capacity optical multiple-image encryption method based on wavelength multiplexing and position multiplexing is proposed. In the encryption process of the proposed method, multiple plane waves of different wavelengths are adopted to illuminate secret images that are placed at different positions along the optical axis. All the secret images are encoded into a single grayscale intensity-only image that is recorded by a monochromic camera by applying a diffractive-imaging based double random phase encoding (DRPE) system. In the decryption process, high accuracy images are decrypted without crosstalk from the intensity image through a multimode phase retrieval algorithm and a two-step iterative shrinkage/thresholding (TwIST) algorithm. The feasibility of the proposed method is demonstrated by numerical simulations.

Multiple-image encryption base on compressed coded aperture imaging

A multiple-image encryption method based on compressed coded aperture imaging and pixel location scrambling operation is proposed. In the encryption process, each plaintext image is compressively encoded by its corresponding random matrix, which is generated via a row and column displacement transformation operation on an original random matrix (ORM) and some auxiliary keys. With the help of charge coupled device (CCD), the superimposed image are then generated by recording and grouping all the encoded images; finally, the ciphertext image is obtained by pixel location scrambling operation for the superimposed image. During decryption, the participant who possesses his/her correct key-group, can successfully reconstruct the corresponding plaintext image by location index key, auxiliary keys, scrambling operation, compressed coded aperture imaging retrieval algorithm. Theoretical analysis and numerical simulations validate the feasibility of the proposed method.

Optical encryption scheme for multiple-image based on spatially angular multiplexing and computer generated hologram

ABSTRACT We propose an optical encryption scheme for multiple images based on angle multiplexing and computer generated hologram(CGH) in this paper. In the encryption process, the original images are firstly modulated by two random phase keys in Fresnel transform with different diffraction distances. Secondly, the modulated images are coherent superposition with solid angle multiplexed reference beams to generate interference fringes and form a compound image. Finally, the compound image is encoded to a CGH by Roman coding method. In the decrypted process, the corresponding experimental system using SLM is built, in which multiple images can be encrypted synchronously with high efficiency. Except random phase key, the proposed encryption system has multiple kind of keys including diffraction distance and wavelength to improve the security. Due to the characteristics of high storage efficiency and simple calculation, this optical multiple-image encryption scheme has important application prospect in improving the efficiency of information transmission and multi-user authentication.

Multiple-image optical encryption based on phase retrieval algorithm and fractional Talbot effect.

A new multiple-image optical encryption scheme based on phase retrieval algorithm and fractional Talbot effect is proposed. In encryption process, by using Fresnel domain phase retrieval algorithm, each image is encoded into a pure phase distribution with different spatial constraints. The spatial constraints are chosen as complementary square aperture array. A Talbot illuminator is designed according to the fractional Talbot effect, which is treated as a decoder to obtain the designed square aperture array. Then all obtained phase distributions are combined into the final ciphertext image. In decryption process, the images can be decoded from the ciphertext by using the Talbot illuminator and keys. Benefit from the use of fractional Talbot effect, the demultiplexing setup of the cryptosystem is very simple and straightforward, with no need of lens. The simulation results prove that the multiplexing capability is considerably enhanced. At the same time, the security analysis proves that the system can resist various attacks.

Asymmetric multiple-image interference cryptosystem using discrete cosine transform and conditional decomposition

In this study, we propose an asymmetric multiple-image encryption technique based on optical interference that utilizes the discrete cosine transform (DCT) and conditional decomposition. First, the DCT spectrum of each original image is cropped by a low-pass filter and spatially multiplexed into a synthetized spectral signal with the same size as the original image. The synthetized spectral signal is then transformed by the DCT to the spatial domain. After undergoing pixel-scrambling, the synthetized signal is encrypted into three phase-only masks (POMs) based on the interference in the discrete multiple-parameter fractional Fourier transform domain and conditional decomposition. One of the POMs is a plaintext-independent cyphertext and the other two are plaintext-dependent private keys. The silhouette of the original image cannot be identified using only one or two of the POMs, all POMs are required. Finally, we demonstrate the performance of our technique through simulations.

An encryption scheme for securing multiple medical images

With the rise in medical imaging tools and telemedicine technology, the distance barriers in providing health care have been reduced by communicating patients data over the internet. To provide patients with privacy, the data are encrypted while transmitting over the insecure network. The paper proposes an encryption scheme for multiple medical images using a new finding in elliptic curve analogue ElGamal cryptosystem and Mersenne Twister pseudo-random number generator. The new finding quickens the encryption time as well as solve the problem of data expansion associated with ElGamal cryptosystem. Results from simulation, security and statistical analyses show that the proposed encryption algorithm can be used for multiple medical images encryption.

Multiple-image encryption based on chaotic phase mask and equal modulus decomposition in quaternion gyrator domain

In order to transmit multiple-image synchronously, this paper introduces an encryption algorithm by combining equal modulus decomposition with quaternion gyrator transform. Firstly, each color image is encoded into a quaternion-valued matrix for a holistic processing. With the chaotic random phase mask, the quaternion gyrator spectrum is obtained. It is subsequently split into a complex-valued interim matrix and the equal modulus decomposition is performed to enhance the security, where the spectrum is divided into two complex-valued masks. Thereafter, the two set of phase masks are respectively superimposed and followed by gyrator transforms. Finally, a real-valued matrix is constructed as the final ciphertext image by splicing the real and imaginary parts together. The phase masks that are generated using the chaotic and real-valued ciphertext are convenient to storage and transmission. Moreover, the initial conditions are closely related with the plaintext images, which makes the cryptosystem achieve high security. Numerical simulations are made to demonstrate the reliability of the proposed cryptosystem.

Single-Shot Optical Multiple-Image Encryption Based on Polarization-Resolved Diffractive Imaging

A new method for optical multiple-image encryption based on polarization-resolved diffraction imaging is proposed in this study. A linearly polarized beam is split into two beams of orthogonal polarization to illuminate different images to be encrypted, and these images are then encrypted into a single white-noise-like intensity image in a single shot. A multi-mode iterative phase-retrieval algorithm is used in the decryption to reconstruct the amplitudes and phases of the secret images simultaneously. Both computer simulations and optical experiments are performed to demonstrate the feasibility and effectiveness of the proposed method.

Multiple-image encryption and authentication based on optical interference by sparsification and space multiplexing

The silhouette problem is the main drawback of the interference-based encryption (IBE) scheme, while the capacity of IBE is always low. In this paper, we utilize sparsification and space multiplexing to process the Fresnel spectrums of multiple original images into one spectrum, and then decompose the synthetized spectrum into two phase-only masks using IBE. Due to the sparsification of the spectrums, the decrypted images can’t be observed by naked eyes with total silhouette-removal, but can be nonlinear correlated with original images. Moreover, the capacity of this proposal is also significantly improved. The feasibility and effectiveness of this proposal have been demonstrated by numerical simulation.

Multiple-image encryption based on angular-multiplexing holography with quick response code and spiral phase keys.

In this research, a novel optical multiple-image encryption method based on angular-multiplexing holography, quick response (QR) code, and spiral phase keys is proposed. With this method, images are transformed into QR codes and subsequently encrypted into a series of encrypted holograms using an angular-multiplexing technique. The encrypted holograms can only be decrypted when the hologram is illuminated with a duplicate of the reference beam and correct fingerprint and spiral phase plate (SPP) keys. The multiplexing performance and key sensitivity of fingerprint and SPP order were both analyzed, showing the high strength of the security of our proposed method.

Multiple-image double-encryption via 2D rotations of a random phase mask with spatially incoherent illumination.

Optical image encryption technique has become extremely important in these years. However, most of the proposed multiple-image encryption systems are illuminated with coherent light source. Here we present a multiple-image double-encryption method with spatially incoherent illumination. The first-encryption of multiple images is based on the speckle rotation decorrelation property, and the second-encryption of images' order is based on the speckle shift decorrelation out of the angular memory-effect range. The double-encryption via two-dimensional rotations of the random phase mask enhances the security and keeps the simplicity of the cryptosystem. The capacity of the ciphertext is greatly increased by multiplexing, and further increased after crosstalk noise removal. The use of incoherent light source reduces the requirements for experimental conditions, and makes the cryptosystem easy to implement in various application scenarios.

Multiple-image encryption scheme based on ghost imaging of Hadamard matrix and spatial multiplexing

This paper proposes a multi-image encryption method based on ghost imaging of Hadamard basis patterns and spatial multiplexing. In the encryption process, firstly, the pixels of each original image are rearranged in ascending order, and then each image rearranged is transformed by Fourier transformation. Most of the spectral information of the images after Fourier transformation is concentrated in the central part, which is sampled by spectrum clipping. Multiple sampled images are combined into one image by spatial multiplexing technology after inverse operation of Fourier transformation is performed. Finally, the combined image is encrypted by ghost imaging using Hadamard basis patterns to obtain ciphertext. In the decryption process, the original plaintext images are reconstructed by compressive sensing algorithm using Hadamard basis patterns and the position index matrices of each original image. We prove the safety and robustness of the proposed method through numerical simulation analysis. Theoretical analysis and numerical simulation analysis prove the safety and robustness of the proposed method.

Multiple-Image Encryption Mechanism Based on Ghost Imaging and Public Key Cryptography

On the basis of ghost imaging, this paper proposes a multiple-image encryption scheme combining public key cryptography and Hadamard basis pattern. In the encryption system, a plurality of light paths are set, and the Hadamard basis patterns are used for illumination, so that each light path is concentrated in a bucket detector to obtain intensity values of all images. Then, all the detected intensity values are encrypted by using public key cryptography algorithm to obtain the final ciphertext. The use of basis patterns allows for high-quality reconstruction. In addition, randomness in the permutation operation and public key cryptography provide a strong security feature for the encryption system. The multiple-image encryption scheme solves the crosstalk problem among images. The basic principle of the encryption scheme is theoretically analyzed, and the feasibility and security of the proposed method are verified by numerical simulation.