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Abstract: In this paper, a novel geometric active contour model for color image is presented. It combines squared local contrast based alignment term about directional information of edge location as part of driving force, together with the improved geodesic active contour model containing Bays error based two-region segmentation information. And all these measures are integrated as a unified framework. Finally, an unconditionally stable and simple numerical scheme, including the narrow band and fast marching methods, is introduced for efficiently implementing this novel model. Experimental results on color image segmentation show that it can extract the contour of color images precisely and its performance is shown much better than the geodesic-aided C–V (GACV) method when directional information about edge location is supplied. [Copyright &y& Elsevier]

The security of patient data is a critical problem for health networks due to the rising popularity of telehealth services and the requirements for clinical data sharing between surgeons, consultants, and medical groups. In contrast to protecting medical data, which includes the cover (i.e., clinical picture), the requirements for protecting other pertinent data are more general. The paper advocates for data encryption before concealment as a robust strategy to uphold patient privacy during medical information exchange. The primary focus of this analysis revolves around a comprehensive exploration of different steganography methods. Through a meticulous examination of various steganographic techniques, including LSB, PVD, and transform domain approaches, this paper provides a detailed analysis of their strengths and limitations. Objective metrics like PSNR and SSIM are employed to dissect the trade-offs between data security and visual fidelity. The research leads to the conclusion that the diagonal queue-based steganog-raphy methodology, supported by chaotic methods, the Linear Feedback Shift Register (LFSR), and the durable Rabin encryption system, is the best course of action. This method enables autonomous data transmission among numerous contacts while ensuring the highest level of confidentiality and integrity of patient data inside e-health networks. In summary, this study provides a comprehensive solution that protects patient data and speeds data transmission inside the expanding framework of e-health networks in order to meet urgent data security concerns in telemedicine and healthcare data exchange. [ABSTRACT FROM AUTHOR]

Due to the rapid development of confidential digital communication over international networks, security is the most significant factor. Steganography is the science of concealed communication and is used to conceal the presence of secret information among the various methods of hiding data in communications. Steganography techniques are usually implemented either in spatial or frequency domains. Some spatial domain methods fundamentally utilize the absolute difference value between neighbor pixels to encode the secret message, categorized as Pixel-Value Differencing Steganography methods (PVDS). In PVDS, the hiding capacity of the adjacent pixels depends on their difference value. Consequently, the secret data will be embedded with a high visual quality of the stego-image. Indicator-based PVDS (IPVDS) technique is derived from the PVDS method. It depends on an Indicator pixel (IP) to extract the secret data correctly. The Genetic Algorithm (GA) approach to optimization depends on the concept of survival of the fittest. This paper introduces two proposals, GA-based steganography schemes (GA-IPVD) and (GA-IPVDM). These new techniques encoded secret data using the IPVDS method. Before embedding data in the cover image, the order of the pixels corresponding to the secret data is modified and rearranged. GA controls the operation of rearranging and modifying the order of pixels and all parameters. The current paper addresses steganography as an optimization problem and seeks to determine the optimal order of the pixels that enhance the matching between the cover image and stego-image to reduce distortion despite high embedded capacity. In the first proposed technique GA-IPVD, GA concentrates on the imperceptibility of embedded data and maximizes the quality of the stego-image according to the given secret data. In contrast, the GA maximizes the capacity of embedded data while maintaining an acceptable amount of stego-image quality in the second proposed technique GA-IPVDM. The proposed systems have embedding key that increase the security of proposed schemes. The experimental results demonstrate that the proposed methods can embed a large quantity of secret data while maintaining an acceptable visual quality of the stego-images. The proposed technique has also demonstrated excellent resistance to a variety of stego-attacks, including the pixel difference histogram (PDH) as well as regular and singular (RS) analyses. Additionally, the out-of-boundary pixel issue (BI), which endures in the majority of modern data hiding algorithms, has been successfully resolved. [ABSTRACT FROM AUTHOR]

Abstract: Recently, Lin and Tsai and Yang et al. proposed secret image sharing schemes with steganography and authentication, which divide a secret image into the shadows and embed the produced shadows in the cover images to form the stego images so as to be transmitted to authorized recipients securely. In addition, these schemes also involve their authentication mechanisms to verify the integrity of the stego images such that the secret image can be restored correctly. Unfortunately, these schemes still have two shortcomings. One is that the weak authentication cannot well protect the integrity of the stego images, so the secret image cannot be recovered completely. The other shortcoming is that the visual quality of the stego images is not good enough. To overcome such drawbacks, in this paper, we propose a novel secret image sharing scheme combining steganography and authentication based on Chinese remainder theorem (CRT). The proposed scheme not only improves the authentication ability but also enhances the visual quality of the stego images. The experimental results show that the proposed scheme is superior to the previously existing methods. [Copyright &y& Elsevier]

In the field of Cryptography, Quantum Key Distribution (QKD) is an application of Quantum Information theory that obtained a great deal of attention in recent years. It allows to establish secret keys between two or more parties, in a much safer way than that implemented by classic cryptography (based on discrete logarithms and factorization of prime numbers). The most promising way of realizing a QKD network (especially over great distances) in the near future is by a constellation of satellites. This paper considers the problem of optimizing the orbits of the satellites in order to maximize the minimum key length shared in a network of ground stations over a fixed amount of time. Different networks of stations are considered and the influence of their geographical disposition on the design and the performance index is highlighted. The networks considered are: a global constellation, a regional European constellation, and two in which there are groups of stations in two different narrow bands of latitude. The effect of Inter-satellite links is then taken into account and how, in some cases, they can improve the performances. Finally the daily performance of the considered constellations are analyzed. [ABSTRACT FROM AUTHOR]

Cryptographic Boolean functions play an important role in the design of symmetric ciphers. Many cryptographic criteria such as balancedness, nonlinearity, correlation immunity and transparency order are connected with the Walsh support of a Boolean function. However, we still know little about the possible structure of the Walsh supports of Boolean functions. In 2005, Carlet and Mesnager studied the Walsh supports of Boolean functions and constructed a class of n -variable Boolean functions whose Walsh support is F 2 n ∖ { 0 } , for n ≥ 10. For n ≤ 6 , it can be verified using the computer that there is no Boolean function with the Walsh Support F 2 n ∖ { 0 }. However, concerning the values of n = 7 , 8 , 9 , it has been an open problem for many years. In this paper, we construct two classes of balanced Boolean functions with the maximum possible Walsh support F 2 n ∖ { 0 } , and partially solve this problem. The first class of functions are of odd variables with n ≥ 9 , and the second class of functions are constructed based on the Maiorana–McFarland bent functions, which are of even variables with n ≥ 8. As a result, the above open problem has been settled for n = 8 , 9 , and the only unsolved case is n = 7. [ABSTRACT FROM AUTHOR]

Performance evaluation plays a vital role in the field of cryptography. It is essential to assess the security, efficiency, and suitability of different algorithms in various applications. By evaluating the performance of cryptography algorithms, we can identify vulnerabilities, weaknesses, and strengths, which are crucial for ensuring the integrity and confidentiality of sensitive data. Moreover, performance evaluation allows for benchmarking, algorithm selection, and continuous improvement in the field, driving advancements in cryptography techniques and enhancing the overall security of systems that rely on cryptography. This paper implements a test algorithm that can evaluate the performance of different parameters for a range of cryptography algorithms. The performance of input is evaluated using parameters such as the Avalanche effect, Correlation coefficient, Bit independence test, Frequency test, Encryption and decryption execution time, Throughput, Brute Force attack, and Information entropy. By comparing results obtained from the performance tests, we can gain valuable insights into the relative strengths and weaknesses of the algorithms. This aids in making informed decisions regarding algorithm selection and improvement, ultimately contributing to the advancement of secure communication and data protection. [ABSTRACT FROM AUTHOR]

Data security has become a basic need in today's world as it shifts more and more toward an all-online mode of operation. All sorts of data and information are now passed from one entity to another over a variety of transmission channels as well as stored on virtual online repositories, and a large chunk of that information is highly private. Over this stream of technological advancements, various data security techniques like encryption, data hiding, etc. have been developed to provide security while transmitting or storing data. This paper proposes an approach to hiding one image inside another image by using CNN in for feature extraction and processing. The proposed model works on the principles of the auto-encoder architecture and is made up of two modules one of which is responsible for the task of processing the secret image and extracting n features and the incorporating those features in the cover image ion such a manner that the cover image retains its original visual qualities and also the secret image gets hidden in it, that module is the Hiding network/Encoder. The other part of this network is the one responsible to then extract the hidden secret image and them create back to its original, this paper is the Reveal network/Decoder. The proposed model is implemented on ImageNet and Pascal-VOC datasets with images of different sizes. In order to judge the models ability to hide the image and to extract is back, PSNR and SSIM are used as performance evaluation Metrics. [ABSTRACT FROM AUTHOR]

Due to the vigorous and ever-evolving demands of the IoT field, resource-constrained devices are being deployed in such areas and several new challenges like sequestration and surveillance, have come into the picture. Multiple lightweight designs have been recommended to overcome the security issues for resource-constrained devices. In applications requiring data to be transmitted fast between various devices, loop unrolling and subsequent pipelining architectures are extremely efficient. In this paper, several efficient hardware implementations of Simeck cipher such as loop unrolling architecture and outer round pipelining technique have been proposed in order to achieve high throughput. This paper has also proposed a bit serialized architecture of the Simeck cipher that reduces the area footprint and used in less resource applications. Our Simeck Serial architecture is 29.5 times more efficient than LiCi cipher and occupies only 7% of the area occupied by LiCi cipher. Similarly, our proposed serial architecture occupies only 13% and 25% of total slices occupied by X 192 and XTEA respectively while still performs 184% and 161% more efficiently. All three architectures are evaluated and compared on the basis of throughput, area utilization, and power consumption for their implementations in different FPGA platforms. • In unroll loop architecture of Simeck cipher, all rounds are unrolled which ultimately vastly reduces the latency while providing an optimum trade-off between area footprint and performance. This makes the design fit for applications demanding less latency. • The proposed outer round pipelining architecture is in turn derived from the full loop unrolling architecture where the loop unrolling greatly simplifies the key scheduling and the round function of the Simeck cipher. With the installation of registers in between each round, throughput is significantly improved and the area footprint is also reduced making design relevant for low resource and high-speed applications. • The proposed serial architecture for Simeck cipher utilizes only 17 slices making it extremely area efficient. [ABSTRACT FROM AUTHOR]

This paper investigates the cluster synchronization of coupled neural networks with reaction–diffusion terms. With the help of impulsive control strategies, some cluster synchronization criteria are proposed by an appropriate event-triggered mechanism. A numerical example is given to verify the validity of the theoretical results. Additionally, the proposed event-triggered impulsive synchronization is successfully applied to image encryption with encouraging cryptanalysis results demonstrating its strong ability to efficiently encrypt images. [ABSTRACT FROM AUTHOR]

Cryptographic circuits, because they contain confidential information, are subject to fraudulent manipulations, commonly called attacks, by ill-intentioned people. Several attacks have been identified and analyzed. One of the most efficient attacks, called DFA (Differential Fault Analysis) cryptanalysis, exploits the presence of faults, injected voluntarily by the attacker, for example with a laser, in the calculations. Countermeasures are then developed and validated to protect the hardware implementation of cryptographic algorithms such as AES algorithm. The present paper aims to protect the AES algorithm against fault injection attacks. In this paper, an efficient fault detection method for the AES algorithm has been developed. In our proposed design, the AES round architecture is devised into three parts and two pipelines registers are inserted in between. Our simulations show that fault detection capabilities of the proposed method for random fault archives 99.539%. The error detection structure can detect the inserted faults with good coverage using the proposed approach. In order to verify the accuracy of our results, we compare our implementation result with the results presented in the literature. Note that the results obtained are competitive with existing implementations. Our fault detection method has the ability to achieve a compromise of safety level and low implementation cost. [ABSTRACT FROM AUTHOR]

This paper presents a cooperative game theory approach to design an optimal video steganography framework. An ideal and perfect video steganography system should provide enough space to embed the secret data without degrading the visual quality. However, in a steganographic system, the payload capacity and visual quality are always inversely proportional to each other. This paper proposes a novel game-theoretic approach using strategy adaption to address this issue. This approach utilizes the Iterative Elimination of Strictly Dominant Strategies (IESDS) method to acquire the optimal solution. The obtained optimal solution comes up with the best trade-off between capacity and visual quality. Also, experimental results infer that the optimal solution outperforms the contemporary methods by attaining significant outcomes. [ABSTRACT FROM AUTHOR]

Smart grid is an efficient and reliable technical framework for controlling computers and automation equipment, and how to ensure the communication security in smart grid is an important issue. Cryptographic authentication scheme is a feasible solution, and the existing authentication schemes for smart grid seek to ensure better performance. Some existing authentication schemes lack comprehensive security considerations and have security or privacy vulnerabilities, which makes them vulnerable to specific attacks. The paper reviews a recent scheme ISG-SLAS (Yu and Park, 2022) and analyzes its potential insecure aspects in detail, including unable to resist ESL attack, cannot provide un-traceability and etc. To this end, the paper designs an improved authentication scheme for smart grid based on symmetric cryptography. Through informal security analyses and formal security analyses with real-or-random (ROR) model and Scyther platform, the security of the proposed scheme is demonstrated. From the perspective of performance, the proposed scheme is compared with ten advanced authentication schemes for smart grid, and the results show that the proposed scheme excels other recent schemes in computational overhead, communication overhead and storage overhead, reduced by 10.1%, 30.8% and 36.1% of ISG-SLAS and 58.9%, 64.1% and 24.3% of the average value of all alternatives respectively. [ABSTRACT FROM AUTHOR]

Cryptography allows our data to be transmitted without giving sensitive information away. This is the art of hiding the information from the malicious third party and making the data accessible to only the sender and the receiver. Building a complex cryptosystem has always been a challenge that can provide relentless security and is infeasible to break. This paper discusses a hybrid cryptosystem that is inspired by the concepts of DNA cryptography and it is further strengthened using multiple components. A random key is used which is generated using the run test of randomness, different DNA encoding combinations, and a state-changing random state mealy machine is used for further strengthening the security. This paper provides a detailed discussion regarding every component the authors used to build the system and also discusses about the vulnerabilities that they found in the existing works with also an overview on how they have addressed them. This paper also discusses the effectiveness and the performance of the proposed system to give an overview of its security measures and also provides some comparative analysis with existing works to back the claim on improved security features. [ABSTRACT FROM AUTHOR]

Visual cryptography encrypts the secret image into n shares (transparency) so that only stacking a qualified number of shares can recover the secret image by the human visual system while no information can be revealed without a large enough number of shares. This paper investigates the (k , n) -threshold Visual Secret Sharing (VSS) model, where one can decrypt the original image by stacking at least k shares and get nothing with less than k shares. There are two main approaches, which have been showed equivalent in some sense, in the literature: codebook-based schemes and random-grid-based schemes; the former is the case of this paper. In general, given any positive integers k and n , it is not easy to design a valid scheme for the (k , n) -threshold VSS model. In this paper, we propose a simple strategy to construct an efficient scheme for the (k , n) -threshold VSS model for any positive integers 2 ≤ k ≤ n. The crucial idea is to establish a seemingly unrelated connection between the (k , n) -threshold VSS scheme and a mathematical structure — the generalized Pascal's triangle. This paper improves and extends previous results in four aspects: • Our construction offers a unified viewpoint and covers several known results. • The resulting scheme has a progressive-viewing property that means the more shares being stacked together the clearer the secret image would be revealed. • The proposed scheme can be constructed explicitly and efficiently based on the generalized Pascal's triangle without a computer. • Performance of the proposed scheme is comparable with known results. [ABSTRACT FROM AUTHOR]

At Eurocrypt 2016, Méaux et al. presented FLIP, a new family of stream ciphers that aimed to enhance the efficiency of homomorphic encryption frameworks. Motivated by FLIP, recent research has focused on the study of Boolean functions with good cryptographic properties when restricted to subsets of the space F 2 n. If an n -variable Boolean function has the property of balancedness when restricted to each set of vectors with fixed Hamming weight between 1 and n − 1 , it is a weightwise perfectly balanced (WPB) Boolean function. In the literature, a few algebraic constructions of WPB functions are known, in which there are some constructions that use iterative method based on functions with low degrees of 1, 2, or 4. In this paper, we generalize the iterative method and contribute a unified construction of WPB functions based on functions with algebraic degrees that can be any power of 2. For any given positive integer d not larger than m , we first provide a class of 2 m -variable Boolean functions with a degree of 2 d − 1. Utilizing these functions, we then present a construction of 2 m -variable WPB functions g m ; d. In particular, g m ; d includes four former classes of WPB functions as special cases when d = 1 , 2 , 3 , m. When d takes other integer values, g m ; d has never appeared before. In addition, we prove the algebraic degree of the constructed WPB functions and compare the weightwise nonlinearity of WPB functions known so far in 8 and 16 variables. [ABSTRACT FROM AUTHOR]

This paper proposes a new robust watermarking method for securing color medical images, where the proposed method relies on combining Slant, Singular Value Decomposition (SVD), and quaternion Fourier-Transform (QFT). The stimulus behind this combination is to improve the invisibility and durability of the proposed method. First, the input cover image is split into four equal parts for fast computation and then encrypted using one-time padding (OTP) encryption to increase robustness. Slant transform is applied to encrypted blocks to increase image compaction. The SVD is applied to the transformed image blocks to preserve quality during the embedding process. Finally, the QFT is applied to increase visual imperceptibility. The binary watermark is first compressed using SVD, scrambled using Arnold encryption to raise security, and then embedded in the modified QFT coefficients. The extraction procedures are the inverse operations of the embedding procedures. The proposed method achieves a good tradeoff between invisibility and robustness compared to existing schemes versus many geometrical, processing, and hybrid attacks. Also, the proposed method attains high visual imperceptibility. The extracted watermark seems to be the original watermark with minimum BER and high NC values. Empirical findings indicate that the proposed method is giving better invisibility and robustness results while maintaining a high capacity compared to other existing watermarking methods. [ABSTRACT FROM AUTHOR]

With the development of Internet and multimedia development, digital image steganography is becoming more extensive in transmitting data with high capacity and security. Although there have been some relevant surveys, there is a lack of relevant surveys on Deep-Learning-based image steganography recently, especially for the developments and perspectives on generative steganography and reversible steganography. So this paper fills this gap and investigates recent developments in Deep-Learning-based image steganography from the viewpoints of strategy and network structures, which is summarized and categorized into ten strategies and five network models. In particular, this paper summarizes the relative merits and challenges of the leading techniques and discusses the research prospect of these fields for promoting the development of steganography. • Image steganography safeguard data from unauthorized access. • The strategies of Image steganography are summarized and classified. • Network structures are summarized and classified for image steganography. • An outlook is discussed on future research work. [ABSTRACT FROM AUTHOR]

In 2019, a chaotic image encryption scheme based on a variant of the Hill cipher (VHC-CIES) was proposed by the Moroccan scholars. VHC-CIES introduces a Hill cipher variant and three improved one-dimensional chaotic maps to enhance the security. In this paper, we conduct a comprehensive cryptanalysis, and find that VHC-CIES can resist neither chosen-plaintext attack nor chosen-ciphertext attack due to its inherent flaws. When it comes to chosen-plaintext attack, firstly, we select a plaintext with the pixel values are all 0 and its corresponding ciphertext, and then use algebraic analysis to obtain the equivalent key stream for cracking VHC-CIES. Secondly, we select a plaintext which the pixel values are invariably 1 and obtain its corresponding ciphertext to obtain some Hill cipher variant parameters of VHC-CIES. Finally, we use the resulting steps of the first two to recover the original plain image from a given target cipher image. Similarly, a chosen-ciphertext attack method can also break VHC-CIES. Theoretical analysis and experimental results show that both chosen-plaintext attack and chosen-ciphertext attack can effectively crack VHC-CIES with data complexity of only O (2). For color images of size 256 × 256 × 3 , when our simulation encryption time is 0.3150 s, the time for complete breaking by chosen-plaintext attack and chosen-ciphertext attack is about 0.6020 s and 0.9643 s, respectively. To improve its security, some suggestions for further improvement are also given. The cryptanalysis work in this paper may provide some reference for the security enhancement of chaos-based image cryptosystem design. [ABSTRACT FROM AUTHOR]

Steganography and steganalysis are two interrelated aspects of the field of information security. Steganography seeks to conceal communications, whereas steganalysis aims to discover or, if possible, recover the data they contain. These two areas have garnered significant interest, especially among law enforcement agencies. Cybercriminals and even terrorists often employ steganography to avoid detection while in possession of incriminating evidence, even when that evidence is encrypted, since cryptography is prohibited or restricted in many countries. Therefore, a deep understanding of cutting-edge techniques for uncovering concealed information is essential in exposing illegal activities. Over the last few years, a number of strong and reliable steganography and steganalysis techniques have been introduced in the literature. This review paper provides a comprehensive overview of deep learning-based steganalysis techniques used to detect hidden information within digital media. The paper covers all types of cover in steganalysis, including image, audio, and video, and discusses the most commonly used deep learning techniques. In addition, the paper explores the use of more advanced deep learning techniques, such as deep transfer learning (DTL) and deep reinforcement learning (DRL), to enhance the performance of steganalysis systems. The paper provides a systematic review of recent research in the field, including data sets and evaluation metrics used in recent studies. It also presents a detailed analysis of DTL-based steganalysis approaches and their performance on different data sets. The review concludes with a discussion on the current state of deep learning-based steganalysis, challenges, and future research directions. • Detect covert messages through neural nets, enhancing steganalysis accuracy. • Steganalysis can benefit from auto-encoders, DNN, CNN, RNN, LSTM, GNN, DBN, and DRN. • Reinforcement learning, transfer learning, and adversarial-based methods are effective to steganalysis. • Transform domain, attention layer, and noise-based features empower steganalysis schemes. • Unsupervised learning extracts nuanced patterns from multimedia for detection. [ABSTRACT FROM AUTHOR]

This paper is based on the typical Sprott-C chaotic system and introduces a single-direction multi-scroll hyper-chaotic system with a scroll count of (2 N + 2) by incorporating a multi-segment square function family. This innovation is the first key point of the paper, emphasizing the controllable scroll count compared to other single or double-scroll chaotic systems. Furthermore, by introducing additional state variables, the system achieves enhanced security and increased information capacity. The second key point highlights the rare occurrence of chaotic burst oscillations in the system's time domain, distributed widely over a range of time, providing a significant innovation. The paper extensively validates the system's dynamical behavior, including assessments of dissipation, equilibrium points, Lyapunov exponents, Poincaré sections, power spectra, and 0–1 tests, contributing to a deeper understanding of the system's complexity. Subsequently, the paper further analyzes system characteristics regarding chaotic bursting oscillations, coexisting attractors, system complexity, and the impact of parameter variations. It underscores the system's versatility and practicality through analog circuit design and FPGA (Field Programmable Gate Array) digital circuit design, confirming its feasibility and expanding its range of applications. Finally, the combination of the multi-scroll hyper-chaotic system with DNA (Deoxyribonucleic Acid) encryption algorithm is applied to image encryption. Through a comprehensive analysis of sensitivity in the key space, histograms, correlation, information entropy, robustness, and time efficiency of encrypted images, the paper verifies the feasibility and security of the encryption method, demonstrating promising prospects for future applications in the field of image encryption. • The introduction of a multi-segment square function family on the basis of the Sprott-C system yields a one-directional, multi-scroll hyper-chaotic attractor with 2(N + 1) scrolls, where N is a positive integer. • The system exhibits rare chaotic bursting oscillations, constituting a significant portion of the time series. • The system's applicability is expanded through the implementation of multi-scroll hyper-chaotic attractors using both analog and digital circuits (FPGA). • A novel cryptographic system is developed by combining the multi-scroll hyper-chaotic attractors with a DNA encryption algorithm, resulting in a highly secure encryption system suitable for image encryption applications. [ABSTRACT FROM AUTHOR]

Abstract: The fundamental concern of Information Assurance today is the issue of trust. Cryptography is one of the main technical defence mechanisms in our armoury, and yet the relationship between the two has rarely been explored. This paper will look at some of the interplay between trust issues and cryptography. [Copyright &y& Elsevier]

IoT devices typically encompass objects or devices equipped with software and internet connectivity, allowing them to collect data. They have limited processing power, memory, and storage. These limitations can make it difficult to secure these devices, as traditional security measures may not be practical. Implementing security for IoT devices can be challenging due to these characteristics, but several steps can be taken to mitigate these challenges. Elliptic Curve Cryptography (ECC) can secure resource constrained IoT devices by providing a more efficient method of encryption and authentication than traditional methods such as RSA. In this paper, we analyzed the lightweight cryptographic algorithm ECC for securing resource-constrained devices such as IoT and evaluated its performance compared to the RSA cryptosystem. The analysis result indicates that ECC is considered to provide stronger security than RSA for the same key length. The CoAP protocol is applied to devices with limited resources, and an examination of its impact is conducted, considering three key performance metrics: CPU usage, bandwidth efficiency, and message communication latency. [ABSTRACT FROM AUTHOR]

The post-quantum cryptography (PQC) standardization process of the National Institute of Standards and Technology (NIST) has entered the final round. Kyber is one of the four key encapsulation mechanism (KEM) finalists. The coefficient multiplication is vulnerable to side-channel attacks. In this paper, we analyzed the multiplication part of Kyber and proposed the methods for constructing ciphertext. By using the chosen ciphertext, more functions can be attacked in the reference implementation of Kyber512. The attacks succeed on the pqm4 implementation with chosen ciphertext while failing with random ciphertext in our experiment environment. For all the attacks, the full secret key recovery can be achieved in a few minutes. • We used chosen ciphertext to attack more position in the decryption of Kyber. • The number of traces used for some functions was reduced by using chosen ciphertext. • In all the experiments, the proposed attack taked only several minutes. [ABSTRACT FROM AUTHOR]

Block symmetric cryptographic algorithms are the essential and inalienable element of any information security system. The main component of block symmetric cryptographic algorithms is the S-box, which largely determines the speed and cryptographic quality of the entire cryptographic transformation. The rapid development of cryptanalysis methods, including the development of quantum computers, requires a more careful research of all possible representations of nonlinear elements of block symmetric cryptographic algorithms. In view of the fact that in addition to the mathematical apparatus of Boolean functions used today to estimate the cryptographic quality of S-boxes, a cryptanalyst can apply the mathematical apparatus of functions of many-valued logic, which makes relevant the task of researching and comparing the cryptographic quality of S-boxes of modern cryptographic algorithms, represented by functions of many-valued logic. This paper presents a research and comparative analysis of nonlinear transformations of the cryptographic algorithms AES, Kalyna, BelT, and Kuznechik when represented by functions of many-valued logic. It was found that only the nonlinear transformation of the BelT cryptographic algorithm is characterized by growth when represented by many-valued logic functions, while the Kalyna cryptographic algorithm demonstrates the greatest decrease in nonlinearity when represented by 16-functions among the cryptographic algorithms researched. The results obtained in the paper indicate a significant unused reserve of cryptographic quality, which can be used in the design of new cryptographic algorithms and their structural elements. [ABSTRACT FROM AUTHOR]

Steganography is a technique that allows confidential data to be delivered securely by embedding the data into cover digital media. In this paper, we propose a simple steganography method for cover gray images with high embedding capacity. The secret pixels are not directly embedded into the cover image by a k -bit LSB substitution method with k in the range [1, 4], but can be extracted from stego image by calculating the Canonical Gray Code (CGC) for the correct number of LSBs known only to sender and receiver. The bit embedding process is performed to minimize the influence of the embedded bits on the pixel intensity of the stego-image and limit the possibility of human perception to follow the distortions of the original image.This effect was achieved by considering virtual embedding of secret bits in canonical Gray code (CGC) calculated for the desired number of n bits (k < n ≤ 8) and optimally adjusting the CGC code to the embedded secret bits, and to the original pixel value of the cover image. The paper, in its experimental part, compares the effectiveness of the proposed method with other techniques. For the results verification, peak signal-to-noise ratio (PSNR), mean square error (MSE), and structural similarity index (SSIM) are calculated. [ABSTRACT FROM AUTHOR]

In this paper we exploit elementary combinatorial techniques to settle different cryptanalytic observations on RC4 that remained unproved for more than two decades. At the same time, we present new observations with theoretical proofs. We first prove the biases (non-randomness) presented by Fluhrer and McGrew (FSE 2000) two decades ago. It is surprising that though the biases have been published long back, and there are many applications of them in cryptanalysis till recent days as well, the proofs have never been presented. In this paper, we complete that task and also show that any such bias immediately provides a glimpse of hidden variables in RC4. Further, we take up the biases of two non-consecutive key-stream bytes skipping one byte in between. We show the incompleteness of such a result presented by SenGupta et al. (JoC, 2013) and provide new observations and proofs in this direction relating the key-stream bytes and glimpses. Similarly, we streamline certain missed observation in the famous Glimpse theorem presented by Jenkins in 1996. Our results point out how biases of RC4 key-stream and the Glimpses of the RC4 hidden variables are related. It is evident from our results that the biases and glimpses are everywhere in RC4 and it needs further investigation as we provide very high magnitude of glimpses that were not known earlier. [ABSTRACT FROM AUTHOR]

Internet of things architecture is the integration of real-world objects and places with the internet. This booming in technology is bringing ease in our lifestyle and making formerly impossible things possible. Internet of things playing a vital role in bridging this gap easily and rapidly. IoT is changing our lifestyle and the way of working the technologies, by bringing them together at the one page in several application areas of daily life. However, IoT has to face several challenges in the form of cyber scams, one of the major challenges IoT has to face is the likelihood of Ransomware attack. Ransomware is a malicious kind of software that restricts access to vital information in some way and demand payment for getting access to this information. The ransomware attack is becoming widespread daily, and it is bringing disastrous consequences, including loss of sensitive data, loss of productivity, data destruction, and loss of reputation and business downtime. Which further leads to millions of dollar daily losses due to the downtime. This is inevitable for organizations to revise their annual cybersecurity goals and need to implement proper resilience and recovery plan to keep business running. However, before proceeding towards providing a practical solution, there is a need to synthesize the existing data and statistics about this crucial attack to make aware to the researchers and practitioners. To fill this gap, this paper provides a comprehensive survey on evolution, prevention and mitigation of Ransomware in IoT context. This paper differs from existing in various dimensions: firstly, it provides deeper insights about Ransomware evolution in IoT. Secondly; it discusses diverse aspects of Ransomware attacks on IoT which include, various types of Ransomware, Current research in Ransomware, Existing techniques to prevent and mitigate Ransomware attacks in IoT along with the ways to deal with an affected machine, the decision about paying the ransom or not, and future emerging trends of Ransomware propagation in IoT. Thirdly, a summary of current research is also provided to show various directions of research. In sum, this detailed survey is expected to be useful for researchers and practitioners who are involved in developing solutions for IoT security. [ABSTRACT FROM AUTHOR]

With the enhancement of people's security awareness, transmitting secret information securely has gradually become a demand for the public. Steganography is a technology of representing secret information within another carrier, aiming at transmitting secret information without causing suspicion. Most of the traditional steganographic algorithms hide secret information by modifying the statistical characteristics, which will leave traces to the carriers. Although these modifications are too tiny to be distinguished by human eyes, they can be detected by steganalysis algorithms. Differently, coverless steganography, also written as steganography without embedding, accomplish the process of information hiding by constructing the relationship between secret information and carriers. Due to no modification to the carriers, all of the steganalysis algorithms are expired. In this paper, more than 90 papers are included to provide a review in coverless steganographic algorithms, covering the major development process of coverless image and video steganographic algorithms. The main contribution of the existing methods is summarized. Besides, the current general issues of capacity, robustness, and security are discussed adequately for both image and video algorithms. Especially, the security of coverless steganography is discussed for the first time from theoretical analysis to actual investigation in this review. [ABSTRACT FROM AUTHOR]

In the application and promotion of UAV in the future, remote sensing image information is transmitted frequently, and its security issues will not be ignored. Aiming at the privacy security problem of portrait information in remote sensing images, this paper proposes a face privacy protection technology scheme based on chaos and DNA cryptography. Firstly, the edge recognition face detection technology is used to identify the face information, and the corresponding matrix is selected as the object of selective encryption. Then, the hash eigenvalues of the selected encrypted object are extracted, and the plaintext-associated chaotic sequences are generated for RGB permutation and zigzag interleaved scrambling in turn. Then, the three channels of RGB are encrypted by dynamic chain DNA encoding in turn. Finally, the cipher-image is obtained after performing discontinuous diffusion and lightweight bit-level confusion. In this paper, chaotic pseudo-random sequences with plaintext correlation and dynamic DNA chain encryption are used to effectively improve the ability of encryption system to resist cryptographic attacks. At the same time, selective encryption can effectively reduce the encryption complexity and performance overhead. Experimental results and security analysis show that the privacy protection scheme has excellent security and efficiency performance. Therefore, the face privacy protection technology scheme reported in this paper has excellent performance and has broad application prospects in UAV and remote sensing communication. [ABSTRACT FROM AUTHOR]

• Orthogonal array with strength 3 has few applications in cryptography to date, although it possesses some excellent cryptographic properties. This paper tries an image encryption algorithm based on this configuration. Simulation results demonstrate the proposed algorithm has good statistical characteristics and strong diffusivity. • The algorithm can encrypt multiple images simultaneously. The cipher images in the same batch are highly correlated, which makes the attacks more difficult. Moreover, if one cipher image is lost, its partial information can be recovered by other cipher images in the same batch. • Unlike other algorithms based on combinatorial configurations, the proposed algorithm doesn't generate the whole configuration. It generates the designated element in orthogonal arrays only when needed. This strategy is more time-saving, and makes the algorithm not limited by the size of encrypted images. In recent years, remote working and studying lead to numerous images being transmitted on the Internet. Many of these images need protection from illegal obtaining or malicious peeping. Under the circumstances, the demand for image encryption algorithms with sufficient capacity and high efficiency is increasing. Multiple-image encryption algorithms can suit the demand well. This paper proposes a multiple-image encryption algorithm based on orthogonal arrays with strength 3. Orthogonal array is a typical configuration in combinatorial design theory, but the application research of orthogonal arrays with strength 3 in image encryption is still a blank. The proposed algorithm combines orthogonal arrays and chaotic maps perfectly to generate multiple 3D permutation maps and substitution maps, then multiple images can be encrypted efficiently. In simulation experiments, the average value of information entropy is 7.9993, the average value of PSNR is 8.884, the average value of MSD is 50, the average values of NPCR and UACI are 99.6127% and 33.4765% respectively. The numerical results demonstrate that the algorithm has enough ability to resist common attacks. [ABSTRACT FROM AUTHOR]

Security of the data is of utmost importance, whenever the data flows on the network. In the current times and t[i]mes to come, cyber security is going to occupy the center stage in the lifecycle of any software. Security is an evergreen and everlasting area, because of the continuous threat from Hackers and Crackers. The proposed work focuses on the protection of the data in the area of Social Network. It has been achieved by the design and development of a new encryption technique called as PentaPlicative Cipher Technique. The PentaPlicative Cipher Technique makes use of multiple keys such as Latitude, Longitude, IP Address and MAC Address of node et al. to securely encrypt the message that needs to be transmitted through a non-secure channel. The paper concludes with an effective comparison in terms of space and time Complexity between Triplicative and PentaPlicative Cipher Technique. [ABSTRACT FROM AUTHOR]

Affine equivalent classes and extended affine equivalent (EA-equivalent for short) classes of vectorial Boolean functions have important applications in cryptography, logic circuit, sequences for communications, etc. Recently, Y. Zhang et al., computed the number of affine equivalent classes of n -variable Boolean functions when 1 ≤ n ≤ 10 by group isomorphism (Zhang et al., 2016). However, the case for affine equivalent vectorial Boolean function remains a challenging open problem. Furthermore, little result for EA-equivalent vectorial Boolean function is known except a trivial lower bound mentioned in Mullen and Panario (2013, P246). In this paper, we focus on the challenging problem of calculating the number of affine equivalent classes and EA-equivalent classes of vectorial Boolean functions. First, for EA-equivalence, we prove that the trivial lower bound proposed in Mullen and Panario (2013) has at least 3 effective figures if n is not too small. We then show that the lower bound also holds for affine equivalent classes. Furthermore, we give an explicit formula and calculate the exact number of affine equivalent classes of (n , m) -functions with 1 ≤ m , n ≤ 11 by GAP. The results in this paper are helpful for the theory and applications of the classifications of vectorial Boolean functions. [ABSTRACT FROM AUTHOR]

The security system engaged to transfer securely the sensitive information over wireless channels must posses some innate features such as high resistivity to various cryptographic attacks, high sensitivity to secret key and plaintext, and strong statistical characteristics of encrypted content. Recently, an image cryptosystem is investigated to secure color images while transmission. The cryptosystem is based on permutation only cipher and employed synchronized 4D hyperchaotic systems. The cryptosystem has credibility of providing ample statistical encryption quality of ciphertext. This paper aims to investigate and analyze the security of this image cryptosystem in terms of its defects and attack resistivity. The security analysis uncovers that cryptosystem holds certain serious security defects and incapable to secure encrypted content. To support the claim, the inherent defects are highlighted; thereby an attack procedure is proposed to show that the cryptosystem is breakable under the proposed cryptanalysis. The attacker can recover complete plaintext image from ciphertext image without knowing secret key. Computer simulations are performed to justify the success of cryptanalysis. The image cryptosystem is all insecure for use in practical applications of image-based secure wireless communication. As a remedy, this paper also suggests security enhancements and an enhanced cryptosystem is proposed to make it completely resistive against above and other types of cryptanalytic attacks and increase on its plain image sensitivity and statistical encryption strength. [ABSTRACT FROM AUTHOR]

The current paper presents a new quantum algorithm for finding multicollisions, often denoted by ℓ -collisions, where an ℓ -collision for a function is a set of ℓ distinct inputs that are mapped by the function to the same value. In cryptology, it is important to study how many queries are required to find an ℓ -collision for a random function of which domain is larger than its range. However, the problem of finding ℓ -collisions for random functions has not received much attention in the quantum setting. The tight bound of quantum query complexity for finding a 2-collisions of a random function has been revealed to be Θ (N 1 / 3) , where N is the size of the range of the function, but neither the lower nor upper bounds are known for general ℓ -collisions. The paper first integrates the results from existing research to derive several new observations, e.g., ℓ -collisions can be generated only with O (N 1 / 2) quantum queries for any integer constant ℓ. It then provides a quantum algorithm that finds an ℓ -collision for a random function with the average quantum query complexity of O (N (2 ℓ − 1 − 1) / (2 ℓ − 1)) , which matches the tight bound of Θ (N 1 / 3) for ℓ = 2 and improves upon the known bounds, including the above simple bound of O (N 1 / 2). More generally, the algorithm achieves the average quantum query complexity of O (c N ⋅ N (2 ℓ − 1 − 1) / (2 ℓ − 1)) , and runs over O ˜ (c N ⋅ N (2 ℓ − 1 − 1) / (2 ℓ − 1)) qubits in O ˜ (c N ⋅ N (2 ℓ − 1 − 1) / (2 ℓ − 1)) expected time for a random function F : X → Y such that | X | ≥ ℓ ⋅ | Y | / c N for any 1 ≤ c N ∈ o (N 1 / (2 ℓ − 1)) , where it is assumed that QRAM is available. With the same query complexity, it is actually able to find a multiclaw for random functions, which is harder to find than a multicollision. [ABSTRACT FROM AUTHOR]

Linearized polynomials appear in many different contexts, such as rank metric codes, cryptography and linear sets, and the main issue regards the characterization of the number of roots from their coefficients. Results of this type have been already proved in [7,10,24]. In this paper we provide bounds and characterizations on the number of roots of linearized polynomials of this form a x + b 0 x q s + b 1 x q s + n + b 2 x q s + 2 n + ... + b t − 1 x q s + n (t − 1) ∈ F q n t x , with gcd ⁡ (s , n) = 1. Also, we characterize the number of roots of such polynomials directly from their coefficients, dealing with matrices which are much smaller than the relative Dickson matrices and the companion matrices used in the previous papers. Furthermore, we develop a method to find explicitly the roots of a such polynomial by finding the roots of a q n -polynomial. Finally, as an application of the above results, we present a family of linear sets of the projective line whose points have a small spectrum of possible weights, containing most of the known families of scattered linear sets. In particular, we carefully study the linear sets in PG (1 , q 6) presented in [9]. [ABSTRACT FROM AUTHOR]

A version of time-bounded Kolmogorov complexity, denoted KT , has received attention in the past several years, due to its close connection to circuit complexity and to the Minimum Circuit Size Problem MCSP. Essentially all results about the complexity of MCSP hold also for MKTP (the problem of computing the KT complexity of a string). Both MKTP and MCSP are hard for SZK (Statistical Zero Knowledge) under BPP -Turing reductions; neither is known to be NP -complete. Recently, some hardness results for MKTP were proved that are not (yet) known to hold for MCSP. In particular, MKTP is hard for DET (a subclass of P) under nonuniform ≤ m NC 0 reductions. In this paper, we improve this, to show that MKTP ‾ is hard for the (apparently larger) class NISZK L under not only ≤ m NC 0 reductions but even under projections. Also MKTP ‾ is hard for NISZK under ≤ m P / poly reductions. Here, NISZK is the class of problems with non-interactive zero-knowledge proofs, and NISZK L is the non-interactive version of the class SZK L that was studied by Dvir et al. As an application, we provide several improved worst-case to average-case reductions to problems in NP , and we obtain a new lower bound on MKTP (which is currently not known to hold for MCSP). • Improved complexity-theoretic hardness results for Kolmogorov complexity. • Improved worst-case to average-case reductions for problems in NP. • A new circuit lower bound for a central meta-complexity problem. [ABSTRACT FROM AUTHOR]

The existing cryptosystem based approaches for privacy-preserving consensus of networked systems are usually limited to those with undirected topologies. This paper proposes a new privacy-preserving algorithm for networked systems with directed topologies to reach confidential consensus. As a prerequisite for applying the algorithm, a structural consensus problem is formulated and the solvability conditions are discussed for an explicitly constructed controller. The controller is then implemented with encryption to achieve consensus while avoiding individual's information leakage to external eavesdroppers and/or malicious internal neighbors. • Sufficient conditions for structural consensus under a directed time-varying network. • A Paillier encryption based privacy-preserving consensus algorithm. • The first privacy-preserving result valid for a directed network. • Explicit design for both first order and second order systems. • Avoidance of information leakage to eavesdroppers and malicious neighbors. [ABSTRACT FROM AUTHOR]

Recently, a new concept called multiplicative differential cryptanalysis and the corresponding c -differential uniformity were introduced by Ellingsen et al. (2020), and then some low differential uniformity functions were constructed. In this paper, we further study the constructions of perfect c -nonlinear (PcN) power functions. First, we give a conjecture on all power functions to be PcN over GF (2 m). Second, several classes of PcN power functions are obtained over finite fields of odd characteristic for c = − 1 and our theorems generalize some results in Bartoli and Timpanella (2020), Hasan et al. (2021) and Zha and Hu (2021). Finally, the c -differential spectrum of a class of almost perfect c -nonlinear (APcN) power functions is determined. [ABSTRACT FROM AUTHOR]

Adoption of IoT technology without considering its security implications may expose network systems to a variety of security breaches. In network systems, IoT edge devices are a major source of security risks. Implementing cryptographic algorithms on most IoT edge devices can be difficult due to their limited resources. As a result, compact implementations of these algorithms on these devices are required. Because the field multiplication operation is at the heart of most cryptographic algorithms, its implementation will have a significant impact on the entire cryptographic algorithm implementation. As a result, in this paper, we propose a small hardware accelerator for performing field multiplication on edge devices. The hardware accelerator is primarily composed of a processor array with a regular structure and local interconnection among its processing elements. The main advantage of the proposed hardware structure is the ability to manage its area, delay, and consumed energy by choosing the appropriate word size l. We implemented the proposed structure using ASIC technology and the obtained results attain average savings in the area of 95.9%. Also, we obtained significant average savings in energy of 63.2%. The acquired results reveal that the offered hardware accelerator is appropriate for usage in resource-constrained IoT edge devices. [ABSTRACT FROM AUTHOR]

Data Encryption Standard (DES) is the first 56-bits secret-key standard that is widely used as a symmetric-key 64-bits block encryption/decryption algorithm. Unfortunately, the rapid increase in computing power makes it possible to find the required bits combination of the secret-key in a short time. Due to the promising trends of Deoxyribonucleic Acid (DNA) in cryptography, this paper presents a DES-DNA based symmetric-key block encryption/decryption algorithm called iEncrypt. iEncrypt has two versions, each of them uses a 64-nucleotides secret-key that makes the secret-key of the proposed algorithm intractable as 128-bits secret-key. The experimental works show that the two versions of iEncrypt are intractable against brute force attacks. Moreover, the reduced version of the proposed algorithm, to 4-rounds, shows the intractability of the first version against differential cryptanalysis attacks in addition to the invisibility of attacking the second version. Plain images data are used as one of the rich characteristics data in the statistical evaluation. Statistically, the encrypted images confirm the intractability of both versions of the proposed algorithm. [ABSTRACT FROM AUTHOR]

In the latest years, there is an increasing emphasis on DICOM medical images, especially in digital medical images transmission to e-health services. Besides, the confidentiality and protection of patients' secure information need more attention and research. In this paper, we propose an enhanced medical image steganographic algorithm to hide patients' secure information in their medical images. The proposed algorithm has a higher level of confidentiality while maintaining a higher quality of the medical image and a higher embedding capacity and robustness. The proposed algorithm has two main steps. The medical cover image is decomposed using an integer wavelet filter in the first step. Moreover, the patients' confidential information is processed using the Arithmetic Coding (AC) and Data Encryption Standard (DES) algorithms to be compressed and encrypted before of the embedding process. In the second step, the insignificant coefficients are selected from the integer wavelet high-frequency subbands of the transformed medical image, and finally, both the target cover bits and the secret bits are grouped during the injection process. The performance of our algorithm was evaluated using different evaluation metrics. The obtained results show that our algorithm outperforms existing ones, with a higher embedding capacity, and a lower imperceptibility. The proposed algorithm can be applied in hospitals and health care canters worldwide. [ABSTRACT FROM AUTHOR]

One of the critical goals of advanced cryptography is to protect data privacy. Although protecting sensitive data has always been essential, it has become much more due to the widespread use of cloud services. Conventional encryption schemes have one drawback: data must be decrypted before processing. Best practices have long recommended that data must be secured at rest and in motion when using public cloud services, i.e., we need encryption at the storage as well as at processing levels. Homomorphic encryption is an advanced cryptographic approach in which the processing of encrypted data is possible. In this paper, we have presented the insights required for understanding homomorphic encryption approaches. We examined and compared two partial homomorphic techniques, RSA and Pallier algorithm based on efficiency, base method, and homomorphic property. [ABSTRACT FROM AUTHOR]

Despite the rapidly growing studies on Arabic text steganography (ATS) noted recently; systematic, in-depth, and critical reviews are in scarcity due to high overlap or low segregation level among the existing review articles linked to this research area. As such, the objective of this paper is to present an extensive systematic literature review (SLR) on the techniques and algorithms used to analyse ATS. Data were retrieved from three primary databases, namely Science direct Journal, IEEE Explore Digital Library, and Scopus Journal. As a result, 214 publications were identified since the past 5 years regarding methods of analysing ATS. A comprehensive SLR was executed to detect a range of unique characteristics from the algorithms, which led to the discovery of a new structure of ATS categories. Essentially, a hybrid method for ATS was identified with other sub-disciplines, especially cryptography, which leads to a new branch in enhancing security for ATS. Other relevant findings included key performance and evaluation criteria used to measure the performance of the algorithms (i.e., capacity, invisibility, robustness, & security). 87 % of the reviewed articles are the capacity measurement performance. Therefore, it disclosed a huge potential for the other two criteria (i.e. invisibility, robustness and security) to set a benchmark for future research endeavour. [ABSTRACT FROM AUTHOR]

Web applications, which dominate the internet, act as communication media between customers and service providers. Web applications are an internet innovation that provide customer services such as e-banking, e-commerce and e-booking. Developing web applications has become increasingly complicated because of security threats and service issues that involve valuable information. Attack methods such as structured query language (SQL) injection insert malicious code within user input data requests to gain unauthorised access, and then the attacker targets a database to manipulate information. In this paper, we propose a prevention method against SQL injection attacks through cryptography and searchable encryption. The proposed method uses a cryptography technique to encrypt all database information, where each piece of user information is encrypted with a separate key. The rest of the database information is ciphered with secret keys, and a searchable encryption technique is used for other database operations to preserve privacy. The login process compares the ciphered username from the database and user entry to authenticate the user. The proposed method is implemented on the PHP and MySQL databases, which are open-source applications. The results show efficient prevention of SQL injection, and the database remains protected against SQL injection attacks [ABSTRACT FROM AUTHOR]