Enhanced Multi-Chaotic Fredkin-Logic-Based Image Encryption for Satellite Imagery with Adaptive Hash-Driven Key Generation

Image encryption plays a vital role in protecting digital data from unauthorized access, cyber threats, and security breaches. With the continuous evolution of attack strategies, developing highly secure encryption mechanisms becomes essential. This paper presents a novel image encryption framework that integrates Cellular Automata (CA) with a chaotic map to enhance image confidentiality and integrity. The spatial complexity of 2-D CA strengthens the key generation process, ensuring a high degree of randomness in the key image. Subsequently, a 3-D coupled logistic map enhances chaotic behavior during encryption, increasing system complexity and security. To further ensure data integrity, Reed-Solomon codes are incorporated into both the key and the encrypted image, improving resilience against transmission errors. The proposed scheme undergoes rigorous evaluation through multiple analyses, achieving high entropy values nearing 7.9989, indicating enhanced encryption randomness. Additionally, it attains an average UACI of 36.9223 and an NPCR of 99.7887, demonstrating strong resistance against differential attacks. Furthermore, the model achieves an average MSE of 88.058 and a PSNR of 29.594 dB, ensuring high-quality image reconstruction. The encryption’s robustness is further confirmed through the NIST randomness test suite, where the model achieves an average p-value of 0.6771 across 15 tests, validating the statistical randomness of the generated cipher images. Moreover, the scheme exhibits strong resilience against noise attacks, confirming its practical applicability in noisy transmission environments. Collectively, these results demonstrate the robustness, effectiveness, and superiority of the proposed image encryption framework.

Reed Solomon codes are widely used to identify and correct data errors in transmission and storage systems. When Reed Solomon (RS) codes are used for high reliable systems, the designer should take into account also for the occurrence of faults in the encoder and decoder blocks. In this paper a method to obtain a self-checking RS decoder is presented and different architectures for its implementation based on concurrent error detection are provided. The proposed method can be used for a wide range of different decoder algorithms with no intervention on the decoder architecture.

Generalized switched synchronization and dependent image encryption using dynamically rotating fractional-order chaotic systems

Reed Solomon codes are used to identify and correct data errors in transmission and storage systems. In this paper we designed a compact RS(255, 223) encoder structure based on analysis of the Reed-Solomon (RS) coding theory used in deep space communications. The encoder is implemented with 32 optimized finite multipliers, of which the redundant operations are reduced to minimize the number of modulo 2 additions or XOR gates based on analyzing the structure of multipliers in RS encoder that are simple and can ensure high speed operations. The simulation results show that the designed structure has advantages such as high efficiency and low complexity ensuring good coding performance.

In the digital era, securing visual information has become critically important due to the exponential growth of multimedia data sharing over insecure channels. Image encryption plays a critical role in preserving data confidentiality, especially when transmitting sensitive visual information. Traditional encryption methods often struggle to efficiently handle the high redundancy, pixel correlation, and dimensionality of color images, making them vulnerable to statistical and differential attacks. To overcome these limitations, this study introduces a robust color image encryption framework that integrates the chaotic behavior of the logistic map with dynamically modulated conic curves to generate spatially adaptive key maps. A user-defined password is hashed using Secure Hash Algorithm (SHA)-256 to generate a seed for the chaotic logistic map, which produces six values used to modulate conic curve coefficients. These coefficients form a spatially varying key map that is applied via pixel-wise XOR across RGB channels. The logistic map ensures high sensitivity to initial conditions, while the conic transformation enhances entropy and diffusion, resulting in a secure and unpredictable encryption process. Experimental validation is conducted on a benchmark image dataset, using evaluation metrics such as Number of Pixel Changing Rate (NPCR), Unified Averaged Changed Intensity (UACI), and Shannon entropy to assess encryption strength. The proposed model achieves an average NPCR of 99.61%, UACI values up to 33.40%, and entropy values approaching 7.89, indicating high resistance to differential and statistical attacks. Additionally, the decryption process accurately reconstructs the original image when the correct password is provided, confirming the reversibility and reliability of the scheme. This framework provides a reliable and computationally efficient approach for encrypting color images securely.

Reed Solomon codes are widely used to identify and correct data errors in transmission and storage systems. Due to the vital importance of these blocks, a very important research topic is the study of the effects of faults on their behavior. The presented architecture exploits some properties of the arithmetic operations on GF(2/sup n/) Galois field, related to the parity of the binary representation of the elements of the field. The encoder has been mapped on an SRAM based FPGA, the self-checking property has been analyzed using a SEU fault model and the performances in terms of area and delay overhead are presented.

In this paper, we propose a digital image encryption scheme based on Tabu Search (TS) algorithm and Chen’s hyperchaos system. First, in order to enhance the security of the algorithm and resist the known-plaintext attack, the key is associated with the ordinary image, and the hash value generated by the ordinary image is used as the initial value of the hyperchaotic system. Moreover, the TS algorithm is used to obtain the optimal subsequence to scramble the sub-block image, which ensures the scrambling effect of the algorithm. In addition, for the sake of minimizing the correlation of neighborhood pixels and strengthening the effect of scrambling, the ordinary image is divided into blocks for scrambling and diffusion. Through simulation and experiments, the key sensitivity, differential attack and pure ciphertext attack are analyzed. Compared with the other encryption schemes, the results verify the effectiveness and reliability of the proposed scheme.

Fractional-order chaotic systems have emerged as powerful tools in secure communications and multimedia protection owing to their memory-dependent dynamics, large key spaces, and high sensitivity to initial conditions. However, most existing fractional-order image encryption schemes rely on fixed-order chaos and conventional solvers, which limit their complexity and reduce unpredictability, while also neglecting the potential of variable fractional-order (VFO) dynamics. Although similar phenomena have been reported in some fractional-order systems, the coexistence of hidden attractors and stable equilibria has not been extensively investigated within VFO frameworks. To address these gaps, this paper introduces a novel discrete variable fractional-order dark matter–dark energy (VFODM-DE) chaotic system. The system is discretized using the piecewise constant argument discretization (PWCAD) method, enabling chaos to emerge at significantly lower fractional orders than previously reported. A comprehensive dynamic analysis is performed, revealing rich behaviors such as multistability, symmetry properties, and hidden attractors coexisting with stable equilibria. Leveraging these enhanced chaotic features, a pseudorandom number generator (PRNG) is constructed from the VFODM-DE system and applied to grayscale image encryption through permutation–diffusion operations. Security evaluations demonstrate that the proposed scheme offers a substantially large key space (approximately 2249) and exceptional key sensitivity. The scheme generates ciphertexts with nearly uniform histograms, extremely low pixel correlation coefficients (less than 0.04), and high information entropy values (close to 8 bits). Moreover, it demonstrates strong resilience against differential attacks, achieving average NPCR and UACI values of about 99.6% and 33.46%, respectively, while maintaining robustness under data loss conditions. In addition, the proposed framework achieves a high encryption throughput, reaching an average speed of 647.56 Mbps. These results confirm that combining VFO dynamics with PWCAD enriches the chaotic complexity and provides a powerful framework for developing efficient and robust chaos-based image encryption algorithms.

Image encryption algorithm based on DNA encoding and CNN

A novel image encryption and decryption scheme integrating two-way chaotic maps, iterative cellular automata, and online tessellation automata

In recent years, owing to the rapid growth of multimedia data transmission over the Internet, security is an important concern in the transmission and storage of digital images. Encryption is one of the most efficient and common practice to uplift image security. Many approaches for image encryption have been introduced including image encryption using chaotic sequences. Recently, the Coupled Map Lattices (CML) based Spatiotemporal Chaotic (STC) system has attracted much attention in the image encryption field. This paper introduces a new scheme for image encryption based on a novel spatiotemporal chaotic system by defining nonlinear dynamics in the Globally Coupled Map Lattice (GCML) using non-neighbourhood coupling. The proposed spatiotemporal chaotic system employs 3D Arnold Cat Map to couple four Nonlinear Chaotic Algorithm (NCA) maps for generating a pseudo random sequence which satisfies uniform distribution, ideal nonlinearity and zero cross-correlation to achieve higher level of security. The image encryption algorithm uses the chaotic sequence generated by one of the NCA map to permute the pixels of the image. Finally, the shuffled image is diffused using the constructed spatiotemporal chaotic sequence. The experimental outcomes reveal that the proposed spatiotemporal system is of high key sensitivity and with large key space. The results obtained from statistical analysis and key sensitivity tests illustrate that the proposed image encryption scheme is secure enough to resist the brute-force attack, entropy attack, statistical attack, differential attacks, chosen-plaintext attack and known-plaintext attack and thus provides an efficient and secure way for real-time image encryption and transmission.

Reed Solomon (RS) codes are widely used to protect information from errors in transmission and storage systems. Most of the RS codes are based on GF(2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> ) Galois Fields and use a byte to encode a symbol providing codewords up to 255 symbols. Codewords with more than 255 symbols can be obtained by using GF(2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sup> ) Galois fields with m > 8, but this choice increases the complexity of the encoding and decoding algorithms. This limitation can be superseded by introducing parity sharing (PS) RS codes that are characterized by a greater flexibility in terms of design parameters. Consequently, a designer can choose between different PS code implementations in order to meet requirements such as bit error rate (BER), hardware complexity, speed, and throughput. This paper analyzes the performance of PS codes in terms of BER with respect to the code parameters, taking into account either random error or erasure rates as two independent probabilities. This approach provides an evaluation that is independent of the communication channel characteristics and extends the results to memory systems in which permanent faults and transient faults can be modeled, respectively, as erasures and random errors. The paper also provides hardware implementations of the PS encoder and decoder and discusses their performances in terms of hardware complexity, speed, and throughput.

Image encryption has recently attracted a lot of scientists and researchers recently as it's an important information security field. Nevertheless, a number of researches were carried out using various techniques, new and practical algorithms were proposed to enhance secure image encryption schemes. Nowadays, chaotic approaches are used in many different fields, including image encryption and cryptosystem design. Digital image encryption techniques depending on chaotic approaches are new. The given approach for encrypting images makes advantage of random chaotic sequences and it can be quick and very secure. This study proposes a new (eight-dimension chaotic cat map). An 8D chaotic cat map which boosts encryption security and efficiency by encoding pixel intensity values using a lookup table. This method is resistant to recognized plain text attacks, differential and statistical attacks, and differential attacks. The base for the map is the chaotic approach, yet the base for the cryptographic algorithm is discrete math. As a result, it offers more rapid and secure methods of data protection. The image encryption, accompanied with proposal's generated key uses fractal geometry's Mandelbrot set and XOR with the image to boost security. The results that obtained from compute several metrics where the average of NPCR (Number of Pixels Change Rate) (99.758333) the value close to 100% and UACI (Unified Average Changing Intensity) (33.2783333) this value near 33% to against differential attacks additional average of Entropy (7.77048333) and the range of PSNR (0.173-0.149) this value and MES (55.7-56.37) proposed scheme has low PSNR values and high MSE. Our findings demonstrat that the suggested approach has an extremely low correlation coefficient and good security level, Moreover, they reflect that this method is good for the actual image encryption.

Differential evolution (DE) is a powerful evolutionary algorithms, widely applied in different fields of science and engineering for solving the problem of optimization. Since image encryption has been viewed as an interesting research topic by many experts and innumerable methods to encrypt images have emerged, currently, the focus is on obtaining optimized images. The paper presents a novel image encryption scheme that uses intertwining logistic map (ILM), DNA encoding and DE optimization. The proposed approach is based on three phases: permutation involving ILM, diffusion engaging DNA and optimization using DE. Parameters like entropy, key sensitivity, secret key space, unified average change in intensity (UACI), correlation coefficient —vertical, horizontal and diagonal, and number of pixel change rate have been evaluated to test the efficiency of the proposed method. The paper also compares this performance with that of the genetic algorithms (GA), used previously for optimization. The significance of this approach is enhancing entropy, the essential characteristic of randomness, resisting against numerous statistical and differential attacks and generating good experimental results. The main contribution of this paper is to present the efficiency of DE in image optimization and exhibit how DE is better than GA.

In the past decade, image encryption has emerged as a matter of interest to scientists and researchers. The paper presents a synchronous permutation-diffusion image encryption algorithm using Intertwining Logistic Map (ILM) and Deoxyribonucleic acid (DNA) for color images. The design of the proposed algorithm is simple, secure and efficient. It is mainly composed of two phases: Permutation and Diffusion. In the first phase, the original image pixels are permuted using the 3D chaotic sequence generated by ILM. In the next phase, the permuted pixels from step one are diffused using DNA XOR operation. The implemented approach is faster as permutation and diffusion operations are performed synchronously in a single iteration. The paper evaluates the performance of the proposed approach using various parameters like key sensitivity, entropy, secret key space, contrast analysis, correlation coefficient (CC)—vertical, horizontal and diagonal, Number of Pixel Change Rate (NPCR) and Unified Average Change in Intensity (UACI). The evaluated results show that use of DNA and synchronization feature with ILM exhibits significant improvement in the information entropy, increase in the randomness feature and contrast, high resistance against the varied statistical and differential attacks, and improvement in encryption efficiency.