A new encryption scheme for color images based on quantum chaotic system in transform domain

Dynamic 3D scrambled image based RGB image encryption scheme using hyperchaotic system and DNA encoding

Color image compression and encryption scheme based on compressive sensing and double random encryption strategy

This work proposes an efficient and secure color and grayscale image encryption scheme that utilizes a chaining of skew tent maps as its pseudorandom number generator. The proposed scheme convolves the shuffling and mixing operations into several rounds for enhanced security. Extensive simulation results are presented to demonstrate the high performance of the proposed scheme. Furthermore, the scheme shows superior performance over existing image encryption schemes with regard to differential attacks.

A color image encryption and decryption scheme based on extended DNA coding and fractional-order 5D hyper-chaotic system

Medical images demand robust privacy protection, driving research into advanced image encryption (IE) schemes. However, current IE schemes still encounter certain challenges in both security and efficiency. Fractional-order Hopfield neural networks (HNNs) demonstrate unique advantages in IE. The introduction of fractional-order calculus operators enables them to possess more complex dynamical behaviors, creating more random and unpredictable keystreams. To enhance privacy protection, this paper introduces a high-performance medical IE scheme that integrates a novel 4D fractional-order HNN with a differentiated encryption strategy (MIES-FHNN-DE). Specifically, MIES-FHNN-DE leverages this 4D fractional-order HNN alongside a 2D hyperchaotic map to generate keystreams collaboratively. This design not only capitalizes on the 4D fractional-order HNN’s intricate dynamics but also sidesteps the efficiency constraints of recent IE schemes. Moreover, MIES-FHNN-DE boosts encryption efficiency through pixel bit splitting and weighted accumulation, ensuring robust security. Rigorous evaluations confirm that MIES-FHNN-DE delivers cutting-edge security performance. It features a large key space (2383), exceptional key sensitivity, extremely low ciphertext pixel correlations (<0.002), excellent ciphertext entropy values (>7.999 bits), uniform ciphertext pixel distributions, outstanding resistance to differential attacks (with average NPCR and UACI values of 99.6096% and 33.4638%, respectively), and remarkable robustness against data loss. Most importantly, MIES-FHNN-DE achieves an average encryption rate as high as 102.5623 Mbps. Compared with recent leading counterparts, MIES-FHNN-DE better meets the privacy protection demands for medical images in emerging fields like medical intelligent analysis and medical cloud services.

To enhance image privacy protection and reduce storage space, this paper proposes an image compression and encryption algorithm that combines compressed sensing, Hachimoji DNA coding, and a 7D hyperchaotic system. The algorithm processes the high-frequency and low-frequency parts after the wavelet transform separately. Sparse high-frequency information is compressed by low-compression measurement. The low-frequency part uses block-compressed sensing, and only a small amount of data is needed to reconstruct a high-quality image. In addition, the measurement matrix is constructed by chaotic sequence, which reduces the demand for memory and transmission bandwidth. To protect compressed data, this paper also presents an image encryption algorithm based on Hachimoji DNA dynamic coding and Joseph dynamic traversal. The algorithm first uses Joseph traversal to disturb the bit position of each pixel dynamically and then implements Hachimoji DNA dynamic coding. At the same time, a new Joseph bidirectional dynamic scrambling-diffusion algorithm is proposed, which gives the encrypted image a uniform grayscale histogram, high information entropy, and sensitivity to resist various attacks effectively.

We devise a color image encryption scheme via combining hyperchaotic map, cross-plane operation and gene theory. First, the hyperchaotic map used in the encryption scheme is analyzed and studied. On the basis of the dynamics of hyperchaotic map, a color image encryption scheme is designed. At the end of the encryption process, a DNA mutation operation is used to increase the encoding images’ randomness and to improve the encryption algorithm’s security. Finally, simulation experiments, performance analysis, and attack tests are performed to prove the effectiveness and security of the designed algorithm. This work provides the possibility of applying chaos theory and gene theory in image encryption.

A novel color image encryption scheme is developed to enhance the security of encryption without increasing the complexity. Firstly, the plain color image is decomposed into three grayscale plain images, which are converted into the frequency domain coefficient matrices (FDCM) with discrete cosine transform (DCT) operation. After that, a two-dimensional (2D) coupled chaotic system is developed and used to generate one group of embedded matrices and another group of encryption matrices, respectively. The embedded matrices are integrated with the FDCM to fulfill the frequency domain encryption, and then the inverse DCT processing is implemented to recover the spatial domain signal. Eventually, under the function of the encryption matrices and the proposed diagonal scrambling algorithm, the final color ciphertext is obtained. The experimental results show that the proposed method can not only ensure efficient encryption but also satisfy various sizes of image encryption. Besides, it has better performance than other similar techniques in statistical feature analysis, such as key space, key sensitivity, anti-differential attack, information entropy, noise attack, etc.

Memristor-coupled asymmetric neural networks: Bionic modeling, chaotic dynamics analysis and encryption application

The rapid evolution of eavesdropping technologies has encouraged regular updates and improvement of encryption systems. Developing a detector-dependent optical encryption scheme to tightly connect the decryption and imaging processes offers great potential to prevent eavesdropping. By designing an optically programmable dual-band photodetector, a color image encryption scheme where the photodetector functions as both a detector and a critical decryption key is demonstrated here. The distinctive optically programmable property of the photodetector enables the manipulation of its long-wavelength sensitivity via short-wavelength photonic stimulation, leading to different imaging outputs between single-pixel imaging and point-scan imaging, which therefore demonstrates a capability to decrypt information hidden in color images. This detector-dependent decryption method can effectively prevent potential information leaks when other detectors are used as eavesdropping devices. Our encryption paradigm opens new avenues for color image encryption using photodetectors, enhancing encryption security by introducing a device-based dimension.

Chaos and compressive sensing based novel image encryption scheme

Color image encryption scheme combining cross-plane Zigzag scrambling and pseudo-random combination RGB component diffusion

In recent years, several encryption schemes have been proposed to protect data from unauthorized access. It is not suitable to use traditional encryption algorithms for image encryption which were proposed for textual data. The encryption schemes used for images are computationally expensive and power hungry, hence not suitable for mobile phone devices. In this paper, an image encryption scheme is proposed which includes pixels shuffling in rows and columns using two key vectors and then Zeta Function is used to further scramble the image. The proposed cipher is a hybrid model based on Rubiks Cube Principle and Zeta Function, resulting in a fast, accurate and energy efficient image encryption scheme which is one of the key requirements of low computing devices especially mobile phones.

Compared with integer order chaotic systems, fractional order chaotic systems can reflect natural phenomena more accurately, which are more suitable for chaotic cryptosystems. In order to explore the application of fractional order chaotic system in cryptography, a novel fractional order hyperchaotic system is constructed and implemented on DSP platform. More progressively, based on Adomian decomposition method, the dynamic behavior is studied by phase diagram, bifurcation diagram, Lyapunov exponent spectrum and spectral entropy (SE) complexity. It is found that each parameter and order have a large range of intervals that can keep the system in a hyperchaotic state. Therefore, the hyperchaotic sequences generated by the constructed fractional order hyperchaotic system have sufficient randomness and are well suited for applications in secure communications. In addition, a color image encryption scheme is designed based on the fractional order hyperchaotic system and DNA dynamic coding. Firstly, the improved Arnold algorithm is used to scramble the original image, then the column cyclic shift method is applied for secondary scrambling, and finally the pixel value is diffused by DNA sequence operation. The security analysis results indicate that the designed encryption algorithm can not only encrypt images effectively, but also has high security and can resist various common attacks.

Fast color image encryption scheme based on 3D orthogonal Latin squares and matching matrix