Trajectory control and image encryption using affine transformation of lorenz 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.

The aroma is one of the most appreciated sensorial attributes of fruit and one of the decisive factors in choosing a food. The flavor industry has grown significantly in recent years and the consumer's desire for new essences has given rise to the development of products from non-conventional fruits. The soursop (Annona muricata L.) is an important tropical fruit known to have a pleasant aroma and distinctive flavor. The objective of this work was to capture the volatiles from soursop pulp using solid phase microextraction (SPME) with the fibers 85 μm CAR/PDMS (carboxen/polydimethylsiloxane), 65 μm PDMS/DVB (polydimethylsiloxane/ divinylbenzene) and 50/30 μm DVB/CAR/PDMS (divinylbenzene/carboxen/ polydimethylsiloxane). The separation of volatile compounds was performed by GC-MS equipped with a nonpolar column (DB5-MS 30 m × 0.25 mm × 0,25 μm), and identified by comparing the mass spectra of the compounds of the samples with NIST (National Institute of Standards & Technology) and by comparison of the linear retention index (LRI). A total of 47 volatile compounds were identified with SPME technique, including 26 esters, 9 terpenes, 4 aldehydes, 1 alcohol, 2 aromatic hydrocarbons, 2 alkanes and 3 unidentified. Among the tested fiber which extracted more number of compounds was PDMS/DVB with a total of 39 compounds, and compounds with greater total area were the methyl hexanoate (39.19%), trans-2-methylhexanoate (25.23%), methyl butanoate (15.35%), trans-2-methyl-butenoate (4.41%) and trans-2-methyl octenoate (2.54%).

In the present paper, the mineral composition of wheat flour consumed in Brazil was evaluated. In the sampling step 54 samples were collected in 15 cities, including principal Brazilian cities such as: Sao Paulo, Rio de Janeiro, Salvador, Porto Alegre, Recife and others. The elements determinate were: calcium, copper, magnesium, manganese, iron, phosphorus, potassium and zinc. The samples were digested using nitric acid and hydrogen peroxide in open system. The analytical technique employed was Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). The method validation (including digestion and determination) was performed using a certified reference material of wheat flour furnished by National Institute of Standards & Technology (NIST). Considering the 54 samples analyzed, the results demonstrated that the macronutrients: calcium, magnesium, potassium and phosphorus have average contents of 0.27, 0.35, 1.71 and 1.92 mg g-1, for concentration ranges of 0.11-1.96, 0.19-0.51, 0.76-3.16 and 0.81-7.15 mg g-1, respectively. The micronutrients: copper, iron, manganese and zinc have average contents of 1.84, 37.8, 8.2 and 9.4 µg g-1, for concentration ranges of 1.00-2.80, 10.5-146.6, 3.9-14.7 and 5.1-13.9 µg g-1, respectively. The results were also evaluated using the multivariate analysis techniques: principal component analysis (PCA) and hierarchical cluster analysis (HCA).

An end-to-end cyber risk assessment process is presented that is based on the combination of guidelines from the National Institute of Standards & Technology (NIST), the standard $5\times 5$ risk matrix, and quantitative methods for generating loss exceedance curves.The NIST guidelines provide a framework for cyber risk assessment, and the standard $5\times 5$ matrix is widely used across the industry for the representation of risk across multiple disciplines. Loss exceedance curves are a means of quantitatively assessing the loss that occurs due to a given risk profile. Combining these different techniques enables us to follow the guidelines, adhere to standard $5\times 5$ risk management practices and develop quantitative metrics simultaneously. Our quantification process is based on the consideration of the NASA and JPL Cost Risk assessment modeling techniques as we define the cost associated with the cybersecurity risk profile of a mission as a function of the mission cost.

The multi-scroll hyper-chaotic coexistence attractors and its application

A novel image encryption scheme comprising of one permutation process and one diffusion process is proposed. In the permutation process, the image sized is expanded to one sized by dividing the plain-image into two parts: one consisting of the higher 4bits and one consisting of the lower 4bits. The permutation operations are done row-by-row and column-by-column to increase the speed. The chaotic generalized Arnold map is utilized to generate chaotic sequence, which is quantized to shuffle the expanded image. The chaotic sequence for permutation process is dependent on plain-image and cipher keys, resulting in good key sensitivity and plain-image sensitivity. To achieve more avalanche effect and larger key space, Chinese Remainder Theorem is applied to diffuse the shuffled image. The key sensitivity and key space of the proposed image encryption have been analyzed as well. The experimental results suggest that the proposed image encryption scheme can be used for secure image and video communication applications.

Chosen plaintext attacks (CPA) pose a significant security risk to encryption algorithms. However, it can be difficult to perform such an attack without direct access to the encryption process. This paper introduces a new cryptoanalysis method that uses hidden CPA to analyze image encryption schemes based on substitution boxes (S-boxes) Unlike traditional CPA methods, the proposed algorithm does not require that they can directly into the encryption process. Instead, a hidden attack vector is embedded in the natural host image to reduce the risk of attack detection. By asking the owner of the encryption algorithm to encrypt this encryption image and provide a cipher image, the input vector can be compared with its encrypted counterpart This can have an effective S-box and break encryption the algorithm, which does not interact directly with the encryption process. Experimental results demonstrate that the proposed method can completely recover cipher images in cascading S-box encryption schemes, regardless of the number of S-boxes used. Additionally, it conceals the CPA vector within the host image imperceptibly, achieving a high PSNR of 49.47 dB, indicating minimal visual distortion. Furthermore, our CPA significantly outperforms existing techniques in speed, recovering a grayscale image in just 1.2 seconds. This method provides a simple yet effective cryptanalysis tool to evaluate the security of such image encryption schemes against CPAs.

In consideration of the reduced chaotic range and susceptibility of a single chaotic map, we exploit the 4D-hyperchaotic system for creating three S-boxes i.e., red, green and blue S-boxes and a logistic map to transform a plain image into DNA strands. Afterwards, a logistic map based fake image is also generated which is also mapped to deoxyribonucleic acid (DNA) strands. Then DNA operations based on logistic map sequence are performed among the DNA strands and the resultant strands are decoded. The decoded strands are substituted by three substitution-boxes (s-boxes) to create an encrypted image. In this research, a cryptanalysis driven design approach is used to prove the security of a proposed encryption scheme. The proposed scheme operates on numerous image dimensions N <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> M and different image file sizes and formats. Experimental results and analysis are completed for visual analysis, key space, key sensitivity, energy analysis, homogeneity analysis, contrast analysis, entropy analysis, histogram analysis, correlation analysis, chosen-plaintext attacks, number of pixels change rate (NPCR), universal average changing intensity (UACI), mean absolute error, robustness against noises and occlusion attacks and encryption efficiency analysis. The visual as well as numerical simulations demonstrate that the proposed algorithm is safe and reliable.

Considering that chaotic systems are highly sensitive to parameters, we design two new parameter variable chaotic systems by constructing parameter perturbation items. These systems are constructed using the state variables of the Liu chaotic system to perturb the parameters of the Lorenz and Chen chaotic systems and are called the Lorenz-Liu chaotic system (LLCS) and Chen-Liu chaotic system (CLCS), respectively. In particular, the parameter perturbation items constructed in this study are not periodic but rather chaotic signals and change in real time. Compared with the original systems, they exhibit more complex randomness and dynamic behaviors. In the proposed cryptosystem, which considers the concept of Deoxyribonucleic Acid (DNA), the solar radio spectrogram is dynamically encoded through the LLCS, and then, the CLCS is used to scramble and diffuse the decoding matrices. In addition, the algorithm uses the 256-bit Secure Hash Algorithm (SHA-256) to generate the initial keys, which enhances the algorithm’s sensitivity to plaintext. Simulation results and security analysis show that the cryptosystem has a large key space and high key sensitivity, and can resist various attacks, such as differential attacks and chosen-plaintext attacks.

Chaos and compressive sensing based novel image encryption scheme

Digital images are widely used for identification, communication, and information exchange, yet their large size, high pixel correlation, and uneven intensity distribution make them vulnerable to theft, manipulation, and statistical inference, thereby requiring encryption mechanisms tailored to image characteristics.Purpose: This study proposes a chaos-based permutation–diffusion scheme that combines Arnold’s Cat Map for pixel permutation and the Duffing Map as a keystream generator for diffusion to strengthen digital image encryption and improve resistance to unauthorized analysis. Methodology: An experimental quantitative approach was conducted through the development of a Python-based desktop application. Ten test images (RGB and grayscale) with varying resolutions were encrypted and decrypted using predefined key settings. Security and performance were evaluated using histogram analysis, entropy, pixel correlation, key sensitivity, processing time, and key space. Findings: The encrypted images exhibit near-uniform histograms, entropy values approaching the ideal for 8-bit images (≈8), and pixel correlation values close to zero, indicating strong statistical concealment. The scheme also demonstrates high key sensitivity, where small key changes prevent meaningful decryption, and a large key space that supports brute-force resistance. Processing time increases with image size but remains practically feasible for desktop implementation. Implications: The proposed scheme can be applied to protect sensitive image data in local desktop environments and image exchange scenarios, reducing risks of statistical attacks and brute-force attempts while maintaining acceptable runtime for common image sizes. Originality: This study delivers an end-to-end integration of Arnold’s Cat Map and the Duffing Map within a permutation–diffusion structure implemented as a Python desktop application, supported by structured security and efficiency evaluation, thereby providing a practical and reproducible contribution to chaos-based image cryptography.

Cryptanalysis of hybrid secure image encryption based on Julia set fractals and three-dimensional Lorenz chaotic map

Chaos based image encryption cryptosystems have garnered much attraction in the recent past. In this regard, recently, two chaos-based image encryption algorithms have been proposed. Both the cryptosystems exhibit very good cryptographic metrics. The first cryptosystem utilizes cryptographic tweaks and other cryptographic primitives to encrypt digital images. This cryptosystem also relies on the idea that a tweak can make the cryptosystem secure. Our paper points out that merely using a tweak doesn’t make the cryptosystem secure and additionally, the structure and stages in the algorithm bear inability to preserve confidentiality of sensitive data. The second cryptosystem is an enhancement of another cryptosystem. Our work indicates that the enhancement in the second cryptosystem is also weak and allows an adversary to retrieve the exact key itself. Both the cryptosystems have similar weaknesses and don’t follow the guidelines laid down by National Institute of Standards and Technology (NIST). It is observed that both the cryptosystems can be broken, to reveal the exact chaotic sequence used for encryption, using a Chosen Plaintext Attack. From this work, it is realized that the weaknesses in the methods can be partially avoided by strictly following the rules laid down by the cryptographic community and NIST. Apart from this, it is expected that future cryptosystems follow all the suggestions mentioned in our work so that, before the cryptosystem is out for attack by cryptanalysts, it is scrutinized sufficiently.

An image encryption scheme based on new spatiotemporal chaos

This report describes the design and intended use of a mass transporter for transferring 1 kg mass standards between different locations and pressure environments without compromising the atmospheric conditions and, therefore, maintaining stability of the surface and mass values of the artifacts. This transporter is intended for transferring 1 kg artifacts between a vacuum mass comparator and the next upgrade of the National Institute of Standards & Technology (NIST) Watt balance.