A novel scheme for image encryption based on piecewise linear chaotic map

This paper proposes an image encryption scheme based on chaotic system with changeable parameters depending on plain-image. A generalized Arnold map, whose control parameters are changeable and image-dependent during the iteration procedure, is utilized to generate chaotic orbits applied to permute the pixel positions. A diffusion function is also designed to realize the diffusion effect by piece-wise linear chaotic map. In both the permutation process and the diffusion process, the keystreams generated by chaotic maps are all strongly dependent on plain-image, and thereby can improve the encryption security efficiently. The major merits of the proposed image encryption scheme include a huge key space, good statistical nature resisting statistical analysis attack, differential attack, and good resistance against known-plaintext attack and chosen- plaintext attack, etc. Experimental results have been carried out with detailed analysis to show that the proposed scheme can be a potential candidate for practical image encryption.

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.

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.

A piecewise linear chaotic map and sequential quadratic programming based robust hybrid particle swarm optimization

A novel image encryption scheme using both pixel level and bit level permutation with chaotic map

Chaos and compressive sensing based novel image encryption scheme

This paper presents an efficient image encryption scheme for color images based on quantum chaotic systems. In this scheme, a new substitution/confusion scheme is achieved based on toral automorphism in integer wavelet transform by scrambling only the Y (Luminance) component of low frequency subband. Then, a chaotic stream encryption scheme is accomplished by generating an intermediate chaotic key stream image with the help of quantum chaotic system. Simulation results justify the feasibility of the proposed scheme in color image encryption purpose.

In conventional interference-based optical encryption schemes, a potential cracker can retrieve partial information (silhouette) of the secret image using only one phase-only mask (POM). We resolve this drawback using a phase-blend operation and piecewise linear chaotic map (PWLCM) to further encode the POMs. One cannot recover a secret image visibly when inverse phase-blend operation and inverse chaotic permutation are not carried out with the correct decryption keys. Chaotic parameters of PWLCM, and random phase-angle function in the phase-blend operation enlarge the key space and improve the security of the proposed system greatly. Numerical simulations and optoelectronic experiments are performed to verify the effectiveness of the proposed scheme.

A novel bit-level image encryption algorithm based on chaotic maps

The security of healthcare and telemedicine systems is a critical issue that must be significantly investigated. Several smart telemedicine applications are expected to be adopted in the medical sector in the incoming years. Healthcare smart products that are connected through Internet to be accessible anytime and anywhere are expected to deal with critical and confidential information such as personal medical images. Therefore, medical image encryption is an important task in telemedicine and healthcare applications. This paper presents an efficient cryptosystem for medical image security based on exploiting the advantages of the de-oxyribo nucleic acid (DNA) rules and chaos maps. In the proposed medical image cryptosystem, logistic chaos map, piecewise linear chaotic map (PWLCM), and DNA encoding are employed. The PWLCM is employed to generate a secret key image. Then, the DNA rules are utilized for encoding the secret key image and the input plain image by rows that are encoded with the logistic chaos map. After that, the proposed logistic map is employed to obtain an intermediate image as another secret key image to set DNA functions row-by-row on the coded original image. Moreover, the intermediate image is decoded in the following stage. Finally, the previous actions are iterated through image columns once again to obtain the best ciphered image. The experimental results reveal that the suggested cryptosystem has a high security with an acceptable processing time. In addition, it can resist various kinds of attacks, such as known-plaintext and chosen-plaintext attacks.

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.

The paper proposes a novel chaos based audio steganography and cryptography method. It is a higher Least Significant Bit (LSB) layers algorithm in which the secret message is encrypted first by one-time pad algorithm. Two chaotic sequences of Piecewise Linear Chaotic Map (PWLCM) were used. In the encryption process, the key for one-time pad is generated by PWLCM chaotic map. In the steganography process, the second sequence of PWLCM is used to generate a random sequence. Then, indices of the ordered generated sequence were used to embed the encrypted message in randomly selected audio samples. The encrypted data were embedded on the higher layers other than the LSB using efficient bits adjustment algorithm, in order to increase the robustness against noise addition or MPEG compression. An analysis is discussed for the proposed scheme. For the steganography algorithm, the proposed scheme overcomes the main two problems for LSB coding, which are the low robustness of secret message extraction and destruction. For the former, the proposed method encrypts the secret message by perfect efficient algorithm which is the one-time pad. Regard of the second one, the secret message is hidden in higher layers which improve the robustness against signal processing manipulation. The main three steganography characteristics were tested and evaluated which are high capacity, perceptual transparency and robustness. Furthermore, the drawbacks of key generation and key distribution for one-time pad is sloved by using the chaotic maps. For the experimental results, waveform analysis and signal-to-noise Ratio are made, which show the high quality of the stego audio, and hence demonstrate the efficiency of the proposed scheme.

In this paper, a novel block digital image encryption scheme based on a chaotic coupled map lattices (CML) is reported. Within this scheme, an original image is decomposed into sub-blocks with a given size, and an external secret key with 192-bit is used and mapped to the system parameters, which are employed to generate a spatiotemporal chaotic binary sequence matrix to encrypt the block original image. Besides, the former sub-block encrypted result will be acted as a feedback to the following sub-block encryption process. The proposed scheme is described in detail, along with the security analyses such as key space analysis, sensitivity analysis, information entropy analysis and correlation coefficients analysis of adjacent pixels. The computer simulation results indicate that the suggested image encryption scheme has some properties desirable in a good security cryptosystem.

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

In this chapter, the great sensitivity of nonlinear systems, and especially of chaotic systems, on the initial conditions and on the variation of their parameters, was used to design a novel image encryption scheme. Until now, a great number of chaotic autonomous continuous systems or discrete dynamical systems, have been used in various image encryption processes, as a source of random numbers. However, in this work, a Chaotic Random Bit Generator (CRBG), which is based on a non-autonomous dynamical system, is used. For ridding from the system the influence of the external source and increasing the security of the proposed generator, the Poincar\(\acute{e}\) section for sampling the signal has been used. As a dynamical system, the very well-known Duffing–van der Pol system has been chosen, presenting very good statistical results. The aforementioned CRBG is the “heart” of the proposed image encryption scheme. Finally, the security analysis of the proposed encryption scheme, based on histogram analysis, correlation of two adjacent pixels, differential analysis and information entropy, demonstrate the robustness of the proposed chaotic encryption scheme against all kinds of statistical, cryptanalytic, and brute-force attacks.