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In today's interconnected world, safeguarding digital data's confidentiality and security is crucial. Cryptography and steganography are two primary methods used for information security. While these methods have diverse applications, there is ongoing exploration into the potential benefits of merging them. This review focuses on journal articles from 2010 onwards and conference papers from 2018 onwards that integrate steganography and cryptography in practical applications. The results are gathered through different databases like Scopus, IEEE, and Web of Science. Our approach involves gaining insights into real-world applications explored in the existing literature and categorizing them based on domains and technological areas. Furthermore, we comprehensively analyze the advantages and limitations associated with these implementations, examining them from three evaluation perspectives: security, performance, and user experience. This categorization offers guidance for future research in unexplored areas, while the evaluation perspectives provide essential considerations for analyzing real-world implementations. [ABSTRACT FROM AUTHOR]

In this article, a new and improvised image watermarking (IW) technique on colored images is proposed to mitigate robustness and imperceptibility issues found often in the past presented schemes. Most schemes exhibit low robustness due to LSB's (Least Significant Bit) and MSB's (Most Significant Bit) based information hiding in the cover image. However, most of these IW schemes have low imperceptibility as the cover image distortion reveals to the attacker due to information hiding in MSB's. Such IW schemes used to hide the secret message via MSBs and LSBs are susceptible to malicious intruder attacks which results in low robustness, whereas, the attacks on MSB's have an impact of reduced imperceptibility. Therefore, this paper propounds a digital IW method named as 2D Otsu algorithm, which allows embedding of a grayscale image into a colored host in the wavelet domain. According to this algorithm, the host image is disintegrated into three color bands of blue, red, and green. Each band is divided into small patches leading to the calculation of entropy followed by finding of the threshold that is estimated by taking the average of entropies of all the patches. Wavelet representation of each patch with entropy less than the threshold is given by applying DWT (Discrete Wavelet Transform). Later, by decomposing gray-scale image into binary bits, secret information embedded by quantization technique into optimal wavelet coefficient blocks either encoding wavelet coefficient differences to 0-bits or 1-bits called MultiBit Encoding (MBE). The results obtained show that the imperceptibility and robustness of this proposed model are superior to other proposed watermarking models and this model gives better results than other models at the same payload. [ABSTRACT FROM AUTHOR]

Recently, a robust steganographic algorithm that achieves errorless robustness against JPEG recompression has been proposed. The method employs a lattice embedding scheme and utilizes the syndrome-trellis code (STC) for practical embedding. However, we have noticed that errorless robust embedding with STC may encounter failures due to modifications on wet coefficients, especially when a high quality factor is used by the compression channel. To solve this problem, we have discovered that using steganographic polar code (SPC) for embedding has better performance in avoiding modifications on wet coefficients. In this paper, we conduct theoretical analysis to prove the better performance of SPC in wet paper embedding. We establish the condition of avoiding modifications on wet coefficients, followed by presenting a recursive calculation method for determining the distribution of columns in the generator matrix of SPC. The findings reveal that SPC can avoid modifications on wet coefficients under a larger number of wet coefficients compared with STC, and therefore we propose a better errorless robust embedding method employing SPC. The experimental results demonstrate that under close security performance, the proposed method achieves a higher success rate compared with embedding with STC. Specifically, when the quality factor of the compressor is 95 and the payload size is 0.4 bpnzac, our method achieves a success rate of 99.85%, surpassing the 91.95% success rate of the embedding with STC. [ABSTRACT FROM AUTHOR]

As communication capabilities of mobile devices continue to advance, ensuring reliability and security has become increasingly crucial. The aerial tracking system presented in this paper provides a useful solution for tracking and tracing objects in various scenarios. To ensure reliability and security, the system incorporates appropriate mechanisms, including Lightweight Cryptography, to prioritize confidentiality and integrity. The Android component of the system has two modes of operation: Tracker Mode, running on a smartphone mounted on a drone (RPA), and Client Mode, running on mobile devices on the ground. In Client Mode, users transmit their positioning and trajectory information via Bluetooth Low Energy beacon mode, which is then relayed to the server backend via the 4G/5G network once the RPA enters an area with coverage. The system provides a reliable and secure solution for situations where tracking and tracing are essential, such as the supervision and control of public areas with capacity control or tracking and localizing people in isolated environments. [ABSTRACT FROM AUTHOR]

The existing encryption schemes of visually secure image have drawbacks, such as excessive concentration of image data and insufficient resistance to various attacks in the transmission channel. Based on the combination of compressed sensing and secret image sharing, this paper presents a visually secure multi-secret image encryption-sharing scheme, which effectively solves the above shortcomings. First, the plain image is perceived as sparse and encrypted by semi-tensor compressed sensing for security. Secondly, the encrypted image is divided into n shadows by secret image sharing. This solves the problem of image data being too centralized and meets the requirements of risk dispersion and intrusion tolerance. Finally, the n shadows are embedded into n carriers by steganography technology to form a visually secure image. On the basis of guaranteeing the quality of image reconstruction, this paper has high compression and security. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) is an important virtual network that allows remote users to access linked multimedia devices. The development of IoT and its ubiquitous application across various domains of everyday life has led to continuous research efforts. Security is a perceptual concern for researchers involved in IoT as it is a key factor in the acceptance of any innovative technology. Numerous research studies have been conducted concentrating on the level of IoT security on a particular mechanism, on specific applications, or on categorizing vulnerabilities, in order to address a defined situation of securing an IoT network. This present paper aims to comprehensively review potential solutions for securing IoT, between emerging and traditional mechanisms, such as blockchain, machine learning, cryptography, and quantum computing. This study provides a comparative analysis of related papers with their characteristics, pros and cons. Accordingly, it taxonomizes relevant solutions based on their achieved security requirements. Furthermore, the potential benefits and challenges of each of the four mechanisms are discussed. [ABSTRACT FROM AUTHOR]

We study the application of Hamming codes to wet paper steganography. To that end, we propose the use of decoding algorithms that do not verify the minimum distance property and present one of these algorithms. We study its properties and show results of some numerical experiments. [ABSTRACT FROM AUTHOR]

Recently, many image encryption algorithms have been proposed. Part of them failed to pass the cryptanalysis test and were found to be unsecure. Some others were more secure and could resist the known cryptanalysis methods. Many of those recent schemes followed a well-known model that consists of encrypting the image's pixels using a variety of techniques and methods. Many algorithms were claimed to be secure and performant to be used in real applications. This paper investigates this claim by performing a comparative analysis between a chaotic algorithm recently proposed and the standard general purpose AES cryptosystem in a web application context. The experimental tests conducted on both algorithms in this paper proved that the pixel-wise algorithms are not suitable for this kind of applications. [ABSTRACT FROM AUTHOR]

With the High Efficiency Video Coding (HEVC) becoming a popular video coding standard in the world, combing the HEVC standard with data hiding methods is a complex task. In this paper, we propose a video steganography method based on intra luma and chroma prediction modes for HEVC. Concerning the characteristics of the quadtree partition and the correlation between the intra luma and chroma prediction modes, we modify the intra chroma prediction modes to embed secret messages. In order to improve the security and embedding efficiency of the method, we use the Logistic chaotic sequence to preprocess the secret messages, and then use matrix coding to select appropriate parameters to embed the messages. The experimental results demonstrate that the proposed method maintains a significant embedding capacity across various encoding structures. Furthermore, it achieves an average ΔPSNR of 0.02 dB, indicating excellent concealment performance while ensuring minimal impact on image quality. [ABSTRACT FROM AUTHOR]

This review paper explores the use of optimization techniques in steganography, the art of hiding secret information within other data. Steganography is a field that has gained significant attention in recent years due to the increasing need for secure communication and data protection. Optimization techniques have been shown to be effective in improving the performance of steganography systems, particularly in terms of maximizing the amount of secret data that can be hidden while minimizing the impact on the cover data. This paper provides a comprehensive overview of the state-of-the-art optimization techniques in steganography, including genetic algorithms, particle swarm optimization, ant colony optimization and fruit fly optimization algorithm. This paper also discusses the advantages and limitations of these techniques and their potential for further development in the future. Also the state-of-the-art methods were compared in terms of PSNR (Peak Signal to Noise Ratio), payload capacity, SSIM (Structured Similarity Index) etc. The review concludes by highlighting the importance of optimization techniques in steganography and their potential impact on the development of more efficient and secure steganography systems. [ABSTRACT FROM AUTHOR]

Around the world, the educational system is evolving. The new trend can be found in traditional classroom systems as well as digitalization systems. Cloud-based Learning Management Systems (LMS) will accelerate the educational industry forward in the next years because they can provide end—user with a versatile, convenient, secure, and cost-effective learning process. The cloud-based LMS approach is the most effective and proper learning model in the worldwide educational sector, particularly if the organization is in a state of depression owing to a global pandemic. It can be utilized over the internet with several users on the same platform. As a result, the initial requirement is important to enable to the LMS model. Despite its many advantages, LMS confronts challenges such as confidentiality, user acceptance, and traffic. In a pandemic like Covid 19, the entire planet depends on a safe LMS platform to establish student and instructor trust. Therefore, with this work, the attempt has been made to explain one LMS model that may provide its users with optimal security, a user-friendly environment, and quick access. This paper discusses the use of the cloud attack, and also cryptographic and steganographic security models and techniques to address these issues. There's also information on what kinds of security vulnerabilities or operations on cloud data are feasible, and also how to deal with them using various algorithms. [ABSTRACT FROM AUTHOR]

With the rapid development of communication technology, the optimization of communication protocol, as a new generation of intelligent traffic system technology, has attracted more and more attention, in particular, the communication technology in traffic. In the authentication protocol of this paper, the symmetric cipher algorithm ZUC and the asymmetric cryptographic algorithm RSA are used as the cryptographic algorithms of the protocol. RSA is used to decrypt digital signatures for messages. In the current communication scheme, node communication does not have scalability and communication requirements in different scenarios, and a population key negotiation communication protocol was proposed in this paper. Employing the kana and random key parameters of the nodes in the roadside cell group, 3 communication protocols for group broadcasting, group to vehicle communication, and RSU communication between groups were designed. The results show that the protocol can meet the security requirements of network communication. The results show that the communication protocol in this paper is safe and reliable. At last, the communication efficiency of communication protocol is analyzed using communication overhead and average delay. The proposed protocol is an efficient communication protocol and the scheme is superior to other schemes in terms of communication overhead and average delay. [ABSTRACT FROM AUTHOR]

This paper intends to contribute to the emerging literature on the ethical problems posed by quantum computing and quantum technologies in general. The key ethical questions are as follows: Does quantum computing pose new ethical problems, or are those raised by quantum computing just a different version of the same ethical problems raised by other technologies, such as nanotechnologies, nuclear plants, or cloud computing? In other words, what is new in quantum computing from an ethical point of view? The paper aims to answer these two questions by (a) developing an analysis of the existing literature on the ethical and social aspects of quantum computing and (b) identifying and analyzing the main ethical problems posed by quantum computing. The conclusion is that quantum computing poses completely new ethical issues that require new conceptual tools and methods. [ABSTRACT FROM AUTHOR]

The exponential growth and wide-area applications of the Internet of Things have garnered a lot of interest from academics and industries, thus becoming one of the most actively studied research paradigms in recent years. Internet of Things is a concept that builds an inter-connected environment where physical devices collect data from the surroundings and customize it to our requirements. It is known for its fast processing and quick response. Edge computing is a platform that performs the computations on the data supplied by the Internet of Thing devices at the network edge that leads to real-time processing. Despite its advantages, privacy protection and security challenges remain a critical concern that must be addressed. This paper aims to give a comprehensive review on cryptographic schemes used for securing edge computing. In particular, we first present a concept of edge computing in the context of IoT including architecture and advantages over cloud computing. We have explored various encryption techniques like identity-based encryption, attribute-based encryption, searchable encryption, and homomorphic encryption that secure the sensitive data before processing it at the network edge. Various parameters of each encryption technique, such as the length of the public key, private key, and ciphetext, are compared. Computational complexity of encryption and decryption is also included in our comparative study. Although many review papers focused on authentication and authorization challenges, this review on encryption techniques in context of edge security was highly needed. We have also looked at some of the other review papers and compared them to our survey to show how important it is. [ABSTRACT FROM AUTHOR]

Homomorphic Encryption (HE) is one of the most popular technologies which assists for keeping the confidentiality and privacy of user data on cloud storage. It can apply a mathematical computation to the ciphertext and return the result as if the operation was performed on the corresponding plaintext. Many of algorithms are known as a class of this interested technology, one of them is Paillier cryptosystem. This paper offers two solutions (MPEA-A and MPEA-B) for Paillier's cryptosystem bottleneck problem which causes delay in Paillier decrypting procedures. MPEA-A and MPEA-B algorithms are based on the Chinese Reminder Theorem CRT with appended principles to achieve the desired goal. Practical implementations are applied to the proposed algorithms, The results show that the two algorithms succeeded in reducing the decryption time with various ratios. The practical implementation proved that MPEA-A can be useful for encrypting with a medium Paillier key size, whereas MPEA-B is preferred for encrypting in a large key size value. [ABSTRACT FROM AUTHOR]

The semidirect discrete logarithm problem (SDLP) is the following analogue of the standard discrete logarithm problem in the semidirect product semigroup G ⋊ End (G) for a finite semigroup G. Given g ∈ G , σ ∈ End (G) , and h = ∏ i = 0 t - 1 σ i (g) for some integer t, the SDLP (G , σ) , for g and h, asks to determine t. As Shor's algorithm crucially depends on commutativity, it is believed not to be applicable to the SDLP. For generic semigroups, the best known algorithm for the SDLP is based on Kuperberg's subexponential time quantum algorithm. Still, the problem plays a central role in the security of certain proposed cryptosystems in the family of semidirect product key exchange. This includes a recently proposed signature protocol called SPDH-Sign. In this paper, we show that the SDLP is even easier in some important special cases. Specifically, for a finite group G, we describe quantum algorithms for the SDLP in G ⋊ Aut (G) for the following two classes of instances: the first one is when G is solvable and the second is when G is a matrix group and a power of σ with a polynomially small exponent is an inner automorphism of G. We further extend the results to groups composed of factors from these classes. A consequence is that SPDH-Sign and similar cryptosystems whose security assumption is based on the presumed hardness of the SDLP in the cases described above are insecure against quantum attacks. The quantum ingredients we rely on are not new: these are Shor's factoring and discrete logarithm algorithms and well-known generalizations. [ABSTRACT FROM AUTHOR]

The low-latency property is becoming increasingly crucial in response to the demand for data processing in the Internet of Things (IoT) environment, especially in lightweight cryptography. A low-latency lightweight block cipher called LTLBC is proposed in this paper. In particular, we propose a hybrid approach of word-wise involutive mapping and a bit-wise permutation, with careful selection of the shift and permutation parameters. This scheme enables LTLBC to achieve better diffusion than Midori and MANTIS. Also, a 4 × 4 S-box which is constructed through a gate-level bottom-up circuit search has good security and latency characteristics. LTLBC mainly focuses on the hardware environment of fully unrolled architecture. LTLBC achieves a minimum latency of around 4.73 ns, with a total area of only 10007.6 μ m 2 based on NanGate 45nm technology. The comprehensive safety analysis shows LTLBC has sufficient redundancy rounds to resist attacks, such as differential cryptanalysis, linear cryptanalysis, impossible differential cryptanalysis, etc. [ABSTRACT FROM AUTHOR]

This paper presents comparative analysis of lattice-based cryptographic schemes, focusing on their runtime and memory performance to evaluate their suitability for secure IoT communications. Specifically, analyzing FrodoKEM, Kyber, and sntrup761, assessing their key generation, encapsulation, and decapsulation operations across various IoT processors. Kyber schemes, particularly Kyber512 and Kyber1024, demonstrate the highest efficiency in terms of battery utilization and computational speed, making them ideal for highly constrained IoT devices. FrodoKEM variants, while providing robust security, show moderate performance, suitable for devices with more processing capacity. sntrup761, however, is less efficient, highlighting the need for careful selection of cryptographic schemes based on specific IoT requirements. The findings underscore the importance of balancing security, speed, and resource usage in PQC implementations, with Kyber schemes emerging as the most promising candidates for secure, resource-constrained IoT environments. Article highlights: Kyber512 is the most battery-efficient choice for securing some IoT devices, ensuring long-lasting performance. FrodoKEM provides strong security but may require more power, making it less ideal for energy-constrained IoT. sntrup761 offers robust security, but its slower operations limit its use in real-time IoT applications. [ABSTRACT FROM AUTHOR]

Digital image steganography serves as a technology facilitating covert communication through digital images by subtly incorporating secret data into a cover image. This practice poses a potential threat, as criminals exploit steganography to transmit illicit content, thereby jeopardizing information security. Consequently, it becomes imperative to implement defensive strategies against steganographic techniques. This paper proposes a novel defense mechanism termed "image vaccine" to safeguard digital images from steganography. The process of "vaccinating" an image renders it immune to steganographic manipulation. Notably, when criminals attempt to embed secret data into vaccinated images, the presence of such hidden information can be detected with a 100% probability, ensuring the consistent identification of stego images. This proactive approach enables the interception of stego image transmission, thereby neutralizing covert communication channels. [ABSTRACT FROM AUTHOR]

A zero-knowledge proof protocol is a cryptographic protocol in which a prover, who knows the witness to a statement, can convince a verifier that the statement is true without revealing any information about the witness. Although zero-knowledge proof protocols are typically executed on electronic computers, there is a line of research to design zero-knowledge proof protocols based on physical objects (e.g., a deck of cards). This is called physical zero-knowledge proof. In this paper, we construct a physical zero-knowledge proof protocol for a logical puzzle called Sukoro. Sukoro has many cells on the puzzle board, like Sudoku, where each cell must be empty or filled with a number from one to four, and each number must match the number of adjacent filled cells, and the same numbers must not be adjacent to each other. In addition, it has a rule that all filled cells must be connected, which is called the connectivity condition. Although some existing protocols deal with the connectivity condition, all existing methods are interactive, which requires the prover's knowledge to determine how the cards are manipulated during the execution of the protocols. In this paper, we give a new method for verifying the connectivity condition in the non-interactive setting, which means that the protocol can be executed without the prover's knowledge, and construct a physical zero-knowledge proof protocol for Sukoro. [ABSTRACT FROM AUTHOR]

Decomposition puzzles are pencil-and-paper logic puzzles that involve partitioning a rectangular grid into several regions to satisfy certain rules. In this paper, we construct a generic card-based protocol called printing protocol, which can be used to physically verify solutions of decompositon puzzles. We apply the printing protocol to develop card-based zero-knowledge proof protocols for two such puzzles: Five Cells and Meadows. These protocols allow a prover to physically show that he/she knows solutions of the puzzles without revealing them. [ABSTRACT FROM AUTHOR]

With the increasing security issues of data transmitted from wireless sensor network terminals, the traditional cryptographic algorithms cannot meet the different security requirements of different types of data in wireless sensor networks (WSN). In this paper, we propose a new lightweight block cipher algorithm RAB that supports variable key length based on Feistel and Substitution-Permutation Network (SPN) structure. To address the inherent slow diffusion in the Feistel structure, the RAB algorithm uses a diffusion layer consisting of MDS matrix. This enhancement ensures that even a 3-round implementation of the RAB algorithm exhibits the ideal avalanche effect, enhancing its security. To handle keys of different lengths and provide different security strengths, the RAB algorithm applies a key schedule function that can receive different lengths of keys. This paper performs differential and linear cryptanalysis of the RAB algorithm using Mixed Integer Linear Programming (MILP) techniques. The results confirm that the RAB algorithm can meet the security demands of resource-constrained devices. Furthermore, the results of the efficiency analyses of the software and hardware performance of the RAB algorithm show that the RAB algorithm has a high software performance efficiency and the hardware performance meets the requirements of lightweight block ciphers. The algorithm is applied to encrypt the data on the sensor nodes, which can correctly encrypt and decrypt the sensor data, and runs smoothly. It indicates that the proposed algorithm is suitable for securing data in resource constrained nodes. [ABSTRACT FROM AUTHOR]

In meet-in-the-middle (MITM) attacks, the sizes of the precomputation tables determine the effectiveness. In this paper, value constraints are presented to reduce the size of the precomputation table in MITM attacks on AES. Based on a differential property of linear combinations of multiple S-boxes, value constraints related to input or output in four and five rounds of AES are explored. Meanwhile, with these value constraints, a method of setting up non-linear equations is proposed to reduce the sizes of the precomputation tables by decreasing the number of byte parameters. Compared with the existing results, their sizes can be reduced by 2 8 , 2 16 , or 2 24 . Finally, some attacks are improved with lower time and memory complexities. [ABSTRACT FROM AUTHOR]

This paper presents two modifications for Loidreau's cryptosystem, a rank metric-based cryptosystem constructed by using Gabidulin codes in the McEliece setting. Recently a polynomial-time key recovery attack was proposed to break this cryptosystem in some cases. To prevent this attack, we propose the use of subcodes to disguise the secret codes in Modification I. In Modification II, we choose a random matrix of low column rank to mix with the secret matrix. Our analysis shows that these two modifications can both resist the existing structural attacks. Furthermore, these modifications have a much more compact representation of public keys compared to Classic McEliece, which has been selected into the fourth round of the NIST-PQC project. [ABSTRACT FROM AUTHOR]

Since the advent of Bitcoin, cryptocurrencies have gained substantial popularity, and crypto wallets have evolved into the predominant tool for safeguarding and managing cryptographic keys to access cryptocurrency funds. Deterministic wallets are proposed as an advanced wallet mechanism to provide benefits such as low-maintenance, easy backup and recovery, and support for functionalities required by cryptocurrencies. Alkeilani Alkadri et al. (ACM CCS'20) presented the first post-quantum secure deterministic wallet scheme, but it exhibits a gap to bridge before achieving practical applicability, as reflected in both their concrete parameters size and computational efficiency. In this paper, we propose an efficient post-quantum secure deterministic wallet scheme. In particular, we present a new construction method for deterministic wallets, prove the security in the quantum random oracle model, and provide an efficient instantiation. The comparison result, with the work of Alkeilani Alkadri et al. (ACM CCS'20), shows our work has a comprehensive improvement on efficiency, e.g., the pk size is ≈ 40.7 times shorter, sk is ≈ 9.2 times shorter, and the signing time is ≈ 3.1 times faster. [ABSTRACT FROM AUTHOR]

The Boolean map χ n : F 2 n → F 2 n , x ↦ y defined by y i = x i + (x i + 1 + 1) x i + 2 (where i ∈ Z / n Z ) is used in various permutations that are part of cryptographic schemes, e.g., Keccak-f (the SHA-3-permutation), ASCON (the winner of the NIST Lightweight competition), Xoodoo, Rasta and Subterranean (2.0). In this paper, we study various algebraic properties of this map. We consider χ n (through vectorial isomorphism) as a univariate polynomial. We show that it is a power function if and only if n = 1 , 3 . We furthermore compute bounds on the sparsity and degree of these univariate polynomials, and the number of different univariate representations. Secondly, we compute the number of monomials of given degree in the inverse of χ n (if it exists). This number coincides with binomial coefficients. Lastly, we consider χ n as a polynomial map, to study whether the same rule ( y i = x i + (x i + 1 + 1) x i + 2 ) gives a bijection on field extensions of F 2 . We show that this is not the case for extensions whose degree is divisible by two or three. Based on these results, we conjecture that this rule does not give a bijection on any extension field of F 2 . [ABSTRACT FROM AUTHOR]

Ascon, a family of algorithms that supports authenticated encryption and hashing, has been selected as the new standard for lightweight cryptography in the NIST Lightweight Cryptography Project. Ascon's permutation and authenticated encryption have been actively analyzed, but there are relatively few analyses on the hashing. In this paper, we concentrate on preimage attacks on Ascon-Xof. We focus on linearizing the polynomials leaked by the hash value to find its inverse. In an attack on 2-round Ascon-Xof, we carefully construct the set of guess bits using a greedy algorithm in the context of guess-and-determine. This allows us to attack Ascon-Xof more efficiently than the method in Dobraunig et al., and we fully implement our attack to demonstrate its effectiveness. We also provide the number of guess bits required to linearize one output bit after 3- and 4-round Ascon's permutation, respectively. In particular, for the first time, we connect the result for 3-round Ascon to a preimage attack on Ascon-Xof with a 64-bit output. Our attacks primarily focus on analyzing weakened versions of Ascon-Xof, where the weakening involves setting all the IV values to 0 and omitting the round constants. Although our attacks do not compromise the security of the full Ascon-Xof, they provide new insights into their security. [ABSTRACT FROM AUTHOR]

Recommender systems have been widely used for implementing personalised content on many mobile online services to reduce computational overload and preserve wireless data for users. The underlying mechanisms used for building recommender systems analyse data collected from users to make recommendations. This poses concerns over the privacy of data from users as both service providers and the cloud will have access. Privacy-preserving recommender systems protect user information by incorporating various cryptographic mechanisms to prevent accessing the data. However, existing works are not practical due to the use of heavy cryptography. In this paper, we propose an efficient privacy-preserving recommender system that takes advantage of clustering to improve efficiency. Using a secure clustering mechanism, user data are assigned to multiple clusters before being fed into the recommendation. Our proposed protocols are privacy-preserving and do not leak information that could be used to identify a data subject. The experiments show that our system is efficient and accurate. [ABSTRACT FROM AUTHOR]

Abstract  The first practical identity based encryption (IBE) scheme was published by Boneh and Franklin at Crypto 2001, based on the elliptic curve pairing. Since that time, many other IBE schemes have been published. In this paper, we describe a variant of Boneh-Franklin with a tight reduction in the random oracle model. Our new scheme is quite efficient compared to existing schemes; moreover, upgrading from Boneh-Franklin to our new scheme is straightforward. [ABSTRACT FROM AUTHOR]

Graph representation learning has made significant strides in various fields, including sociology and biology, in recent years. However, the majority of research has focused on static graphs, neglecting the temporality and continuity of edges in dynamic graphs. Furthermore, dynamic data are vulnerable to various security threats, such as data privacy breaches and confidentiality attacks. To tackle this issue, the present paper proposes a data security detection method based on a continuous-time graph embedding framework (CTDGE). The framework models temporal dependencies and embeds data using a graph representation learning method. A machine learning algorithm is then employed to classify and predict the embedded data to detect if it is secure or not. Experimental results show that this method performs well in data security detection, surpassing several dynamic graph embedding methods by 5% in terms of AUC metrics. Furthermore, the proposed framework outperforms other dynamic baseline methods in the node classification task of large-scale graphs containing 4321477 temporal information edges, resulting in a 10% improvement in the F1 score metric. The framework is also robust and scalable for application in various data security domains. This work is important for promoting the use of continuous-time graph embedding framework in the field of data security. [ABSTRACT FROM AUTHOR]

Steganography is used at a large scale in various security systems. It is the science and art of hiding secret information into data. Various steganography schemes have been proposed over the years, but most of them are not promising enough to provide a large capacity of embedding and visually prevent the image's degradation. Histograms can reveal the existence of secret information, and it is also an essential issue in the security of the data. In this Paper, the main objective is to reduce the bit-flip cost count and maximize the PSNR value to reduce the image distortion and keep the data secure by using secret keys while embedding. In this proposed paper, the genetic algorithm (GA) is employed to select the best chromosome that has the minimum bit-flip cost count and maximum PSNR. Data security is achieved by the secret key generated from Hamiltonian path for embedding and retrieving of data. The proposed technique is robust against steganographic attacks and even if presence of data is observed it not possible to guess the embedding pattern. The result section demonstrates that the proposed technique outperform the existing techniques by increasing the PSNR significantly by approx 7 percent that lead to the increase in PSNR value up to 41.8dB for three bit per pixel embedding. [ABSTRACT FROM AUTHOR]

Generating a secret key from the physical layer is one of the most challenging topics in cryptography. Secret key generation rate (SKGR) and secrecy rate (SR) are two important concepts for any secure communication scheme. In this paper, we first propose a new power allocation strategy to minimize the power consumption under a given SKGR constraint for orthogonal frequency division (OFDM) based communication systems. Due to the non-convex nature of the SKGR expression, we convert the optimization problem into a convex problem. In the continuation of this paper, we investigate the effects of the proposed power allocation strategy on the SR performance. Simulation results demonstrate that using the obtained optimum power vector, which was calculated in the key generation phase, we achieve a better level of SR in the data communication phase. The simulation results also verify that the average SR performance obtained by the proposed method is superior to the geometric programing (GP)-based method. [ABSTRACT FROM AUTHOR]

I am very pleased to present this special issue of New Generation Computing for Card-Based Cryptography. This special issue consists of six research papers that contain advanced and cutting-edge new results on the emerging research area, card-based cryptography. In the paper, I Card-based Cryptography with Dihedral Symmetry i , Kazumasa Shinagawa proposes a novel kind of cards, called the dihedral cards, by which he designs several important protocols suitable especially for multi-valued computations; he also constructs a framework capturing a wide range of types of physical cards. [Extracted from the article]

Blockchain is one of the promising technologies nowadays due to its unique characteristics like security, privacy, data integrity, decentralization, immutability, and traceability. Originally used to implement cryptocurrencies, recently numerous applications have employed blockchain in their architectures including applications targeted for the internet of things (IoT) environments. It is expected that by 2025 more than 21 billion IoT devices will be used especially with use of cloud, fog and edge computing architectures. Integrating blockchain in the IoT architecture provides many advantages such as enhancing security and privacy, better speed and costs, traceability and reliability, and elimination of single point of failure. On the other hand, many issues and challenges have arisen and should be addressed. Typically, IoT system consists of lightweight devices with limited hardware resources and constraints. Hence, the energy efficiency is a fundamental challenge in such devices. The main motivation of this paper is to survey designing a secure and energy efficient blockchain-based IoT implementation using a suitable hardware design. The paper classifies, presents and analyzes existing solutions to better implement IoT environment combined with blockchain technology. Our investigation demonstrations that most of lightweight solutions handle either the energy or security issue separately. Moreover, many works are theoretical-based analysis and solutions without considering the real blockchain-based IoT validation design. Energy evaluation for IoT hardware devices is not given the adequate research bandwidth. Additionally, limited works evaluated their techniques from hardware constrained device perspective. It is recommended that the performance of any proposed solution should be validated using real designs. The hardware perspective evaluation should be in mind for efficient blockchain-based IoT hardware implementation. The proposed lightweight solutions should focus more on efficient energy implementation while considering the lightweight security mechanisms. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses articles in the issue on topics including reversible data hiding, cryptography and steganography.

Homomorphic evaluation of hash functions offers a solution to the challenge of data integrity authentication in the context of homomorphic encryption. The earliest attempt to achieve homomorphic evaluation of SHA-256 hash function was proposed by Mella and Susella (in: Cryptography and coding—14th IMA international conference, IMACC 2013. Lecture notes in computer science, vol 8308. Springer, Heidelberg, pp 28–44, 2013. https://doi.org/10.1007/978-3-642-45239-0%5f3.) based on the BGV scheme. Unfortunately, their implementation faced significant limitations due to the exceedingly high multiplicative depth, rendering it impractical. Recently, a homomorphic implementation of SHA-256 based on the TFHE scheme (Homomorphic evaluation of SHA-256. https://github.com/zama-ai/tfhe-rs/tree/main/tfhe/examples/sha256%5fbool) brings it from theory to reality, however, its current efficiency remains insufficient. In this paper, we revisit the homomorphic evaluation of the SHA-256 hash function in the context of TFHE, further reducing the reliance on gate bootstrapping and enhancing evaluation latency. Specifically, we primarily utilize ternary gates to reduce the number of gate bootstrappings required for logic functions in message expansion and addition of modulo 2 32 in iterative compression. Furthermore, we demonstrate that our optimization techniques are applicable to the Chinese commercial cryptographic hash SM3. Finally, we give specific comparative implementations based on the TFHE-rs library. Experiments demonstrate that our optimization techniques lead to an improvement of approximately 35–50% compared with the state-of-the-art result under different cores. [ABSTRACT FROM AUTHOR]

The three party authenticated key agreement protocol assists two parties in affirming one another and agreeing on a shared session key with the assistance of a trusted server. Chaos-based cryptography has seen considerable progress due to the sound characteristics of chaotic systems. Nowadays, many researchers are actively working in this direction and have proposed various three party authenticated key agreement protocols based on chaotic maps. In this paper, we analysed the Zheng et al. 's scheme (IEEE Access 8:66150–66162, 2020, https://doi.org/10.1109/ACCESS.2020.2979251) and found that it is vulnerable to various attacks like verification table theft attack, impersonation attacks and also it does not provide anonymity to users. Zheng et al.'s scheme also has flaw in registration phase and uses timestamps for key freshness. In this article, we proposed a three party chaotic based authenticated key agreement protocol which is secured against aforementioned attacks. Authors are also compared the proposed scheme with other comparable and existing schemes in terms of security features, computation cost, and communication cost. The comparison analysis shows that the proposed scheme has more security features at a lower cost in computing and communication. We have also demonstrated the security of the proposed protocol within the framework of the random oracle model. [ABSTRACT FROM AUTHOR]

A large number of interconnected smart devices or objects interact with the physical environment known as the Internet of Things (IoT). These networks efficiently perform complex tasks with a high level of intelligence without human intervention and require run-time processing and computation. Edge computing is introduced where devices are placed at the edge between the data source and the cloud. These devices can provide more powerful computational and storage capabilities to IoT users. With various benefits, one of the significant requirements is secure and trustworthy data communication. Various trust management schemes are introduced to guarantee the trustworthiness and isolation of the malicious nodes and give preference to the most trustworthy ones. The existing schemes selected trustworthy nodes again and again from the path without considering the load factor which leads them to be more vulnerable for the Denial of Services (DoS) attacks. In this paper, we propose a Link-based Penalized Trust Management scheme to provide trust management and consider load factors for the selection of most trustworthy nodes and provide a preemptive measure to secure the network from DoS attacks based on its link's association. Simulation results indicate the better performance of the proposed scheme as compared with existing schemes. [ABSTRACT FROM AUTHOR]

Cryptography plays a key role in information systems of financial industry. With the rapid development of financial industry, the scale of the financial cryptographic services continues to expand, and the volume of terminal devices increased significantly, causing problems such as system complexity and extreme workload. The centralized data processing model enabled by cloud computing can ease these problems to some extent, but when the data produced by various kinds of devices (e.g. IoT devices) continues to increase rapidly, cloud computing-based services subsequentially cannot meet the demand of real-time and efficient data processing. The edge computing is an emerging computing model, which is capable of hierarchically managing the resource, and supporting the deployment of cryptographic services at the edge. The edge computing-based cryptographic service separates data encryption/ decryption processing and provides low-level interfaces for financial business systems. It could simplify the way financial business systems obtain cryptographic services. In this paper, we propose an edge oriented cryptographic key management service, which consists of system monitor module, key management module and security management module. The proposed service enables the management of the whole life cycle of cryptographic keys, and reconstructs the process of cryptographic key. In a 1-year continuous testing, the proposed system achieved a total of 36 million cryptographic key distributions, and each cryptographic key has a lifecycle of 1.5 days on average. The TPS reached 15,000, and the system availability reached 99.99% throughout the year. The proposed system now is officially available as a commercial cryptographic service platform. [ABSTRACT FROM AUTHOR]

The Mixed Integer Linear Programming (MILP) technique has been widely applied in the realm of symmetric-key cryptanalysis. In this paper, we propose a new bitwise breakdown MILP modeling strategy for describing the linear propagation rules of modular addition-based operations. We apply such new techniques to cryptanalysis of the SNOW stream cipher family and find new linear masks: we use the MILP model to find many linear mask candidates among which the best ones are identified with particular algebraic bias evaluation techniques. For SNOW 3G, the correlation of the linear mask we found is the highest on record: such results are highly likely to be optimal according to our analysis. For SNOW 2.0, we find new masks matching the correlation record and many new sub-optimal masks applicable to improving correlation attacks. For SNOW-V/Vi, by investigating both bitwise and truncated linear masks, we find all linear masks having the highest correlation and prove the optimum of the corresponding truncated patterns under the "fewest active S-box preferred" strategy. By using the newly found linear masks, we give correlation attacks on the SNOW family with improved complexities. We emphasize that the newly proposed uniform MILP-aided framework can be potentially applied to analyze LFSR-FSM structures composed of modular addition and S-box as non-linear components. [ABSTRACT FROM AUTHOR]

In this paper, we have presented an image encryption technique using random graph traversal, chaotic maps, and a secure hashing algorithm. Due to the innate features of images, such as a high correlation between pixels, high redundancy, and the bulk capacity of images, traditional cryptography methods cannot be used for image encryption. Several theories can be exploited for image cryptography, but we choose random graph traversal because of its immense potential in this field. Chaotic maps are highly sensitive to initial conditions, which makes them suitable for encryption tasks. It is difficult to predict the dynamic properties of high-dimensional maps since they are more complex in nature. We use a three-dimensional Lorenz map to make our algorithm more robust. The initial parameters of the Lorenz map are modified by using the SHA-3 algorithm in the plain image. All the pixels of the image are assumed to be nodes of a graph, and a novel method is used to find a random path of pixel nodes in this graph network using a Lorenz map sequence such that each pixel node is visited exactly once. Finally, the chaotic sequences are used to diffuse the image into three sub-parts to obtain the final cipher image. The experiment has been performed on several standard images to compare the proposed approach with related methods in terms of qualitative and quantitative measures. The proposed approach fails to decrypt the cipher image even with a key deviation as low as 10 - 17 compared to related methods, which show excellent key sensitivity compared to the proposed method. Experimental results show that the proposed algorithm is highly secure and can resist several attacks. [ABSTRACT FROM AUTHOR]

The foundation of this research is the quantum implementation of two hashing algorithms, namely Secure Hash Algorithm (SHA1) and Message Digest (MD5). Quantum cryptography is a challenging topic in network security for future networks. Quantum cryptography is an outgrowth of two broad topics—cryptology and cryptanalysis. In this paper, SHA1 and MD5 algorithms are designed and implemented for quantum computers. The main aim is to study and investigate the time requirement to build a hash and the bit rate at which a hash value is sent through. In this paper, a comprehensive analysis of these two algorithms is performed. Experiments have been done to compare and contrast the performances of the classical and proposed algorithms. In the experiment, it was found that the total time of execution of quantum SHA1 and quantum MD5 is much higher than the classical SHA1 and MD5. During quantum MD5 execution, it is observed that the time doubles when the number of chunks is increased from 1 to 2. Another experimental observation is that the execution time of the implemented algorithms depends upon the processor's speed. [ABSTRACT FROM AUTHOR]

In symmetric cryptography, block ciphers, stream ciphers and permutations often make use of a round function and many round functions consist of a linear and a non-linear layer. One that is often used is based on the cellular automaton that is denoted by χ as a Boolean map on bi-infinite sequences, F 2 Z . It is defined by σ ↦ ν where each ν i = σ i + (σ i + 1 + 1) σ i + 2 . A map χ n is a map that operates on n-bit arrays with periodic boundary conditions. This corresponds with χ restricted to periodic infinite sequences with period that divides n. This map χ n is used in various permutations, e.g., Keccak-f (the permutation in SHA-3), ASCON (the NIST standard for lightweight cryptography), Xoodoo, Rasta and Subterranean (2.0). In this paper, we characterize the graph of χ on periodic sequences. It turns out that χ is surjective on the set of all periodic sequences. We will show what sequences will give collisions after one application of χ . We prove that, for odd n, the order of χ n (in the group of bijective maps on F 2 n ) is 2 ⌈ lg (n + 1 2) ⌉ . A given periodic sequence lies on a cycle in the graph of χ , or it can be represented as a polynomial. By regarding the divisors of such a polynomial one can see whether it lies in a cycle, or after how many iterations of χ it will. Furthermore, we can see, for a given σ , the length of the cycle in its component in the state diagram. Finally, we extend the surjectivity of χ to F 2 Z , thus to include non-periodic sequences. [ABSTRACT FROM AUTHOR]

In recent years, deep learning has been used in steganography scheme, and the implemented solution had a large hidden capacity. In order to further study the effect of basic deep learning network on image steganography, a deep learning image steganography scheme based on ResNet was proposed in this paper, which applied the idea of residual blocks in ResNet to the field of image steganography. Image hiding and image extraction were realized by encoder network and decoder network. In the proposed scheme, by setting the balance parameter during training, different hiding and extraction qualities could be obtained for different scenarios. At the same time, a new performance analysis method was proposed for the field of deep steganography: the scatter plots of PSNR and SSIM. For a test set with a large amount of data, it could clearly reflect the performance of the solution, and it had a certain degree of application value in the field of deep steganography. The experimental results showed that the scheme had better invisibility when hiding, high data accuracy when extracting, and had certain advantages compared with the existing scheme. And it performed better when detected by steganalysis tools. [ABSTRACT FROM AUTHOR]

Mission-critical applications refer to the real-time applications, which require fast and secure service provisioning, such as defense sector and disaster management. This paper proposes a delay-aware and secure service provisioning model for such types of applications. As a use-case, we have considered the defense sector, which is a vital sector for a country's all-round well-being including security, safety, society, and economy. In the conventional sensor-cloud model, the sensor data is stored and processed in the cloud. However, the sensor nodes have small coverage and the use of the long distant cloud servers increases the delay. Therefore, the conventional sensor-cloud model may not be efficient for defense application. Moreover, data hiding for security purposes is another important aspect of this field. To address these challenges, this paper proposes a mobility-aware sensor-fog paradigm for mission-critical applications based on network coding and steganography, referred to as Mobi-Sense. In Mobi-Sense, steganography is used for hiding the data during transmission. The theoretical results demonstrate that Mobi-Sense outperforms the existing frameworks with respect to delay and power consumption by ∼ (40 - 80) %. The simulation results present that Mobi-Sense reduces the delay by ∼ (18 - 40) % than the conventional sensor-cloud framework for mission-critical applications. An optimal path finding algorithm based on deep learning has been deployed in the context of disaster scenario. The experimental analysis shows that the proposed optimal path finding method achieves precision and accuracy above 90%. This is observed that our proposed modules have outperformed existing baselines in terms of accuracy, delay, and power consumption. [ABSTRACT FROM AUTHOR]

With the rapid evolvement of cryptanalysis, attacks with multiple distinguishers have emerged gradually. Many new cryptanalytic methods such as multiple differential cryptanalysis, multiple linear cryptanalysis, multiple impossible differential cryptanalysis, multidimensional zero correlation linear cryptanalysis have been proposed, which have greatly enhanced the efficiency of corresponding attacks. During these attacks, discovering more distinguishers has always been a trivial and manual work. Many cryptographers use their expertise and experience to achieve this goal. However, in most cases, either the length of the attack or the number of distinguishers is underestimated. This paper proposes a generic method to discover more different distinguishers based on a new property called "weak rotational property". Block ciphers with this property can easily discover more distinguishers such as truncated differential distinguishers, impossible differential distinguishers and zero correlation linear distinguishers in a theoretical approach. Then the number of equivalent distinguishers is proved in a mathematical form. As an application, this paper focuses on SIMON family ciphers to illustrate how this property improves cryptanalysis. For the section of application, first of all, SIMON family ciphers are proved to have weak rotational property. Thus the number of corresponding discovered distinguishers can be increased for SIMON. Then, some earlier observations on SIMON are extended accordingly to this new property. Finally, based on the idea of weak rotational property and equivalent-subkey technique, an improved impossible differential cryptanalysis on SIMON is proposed. For SIMON32(64)/SIMON128(128)/SIMON128(192), the rounds attacked are all extended by one round. For other variants of SIMON, current best non full codebook impossible differential attacks are derived. The successful application of weak rotational property indicates its potential in cryptanalysis. [ABSTRACT FROM AUTHOR]

This paper presents a quantum image steganography algorithm based on HSI color space embedding technique. To increase the security of sensitive information, a three-dimensional hyperchaotic system incorporating sinusoidal mapping, Henon mapping, and Cubic mapping using the cascade modulation method is first presented. Additionally, a brand-new steganography algorithm built on the HSI color space embedding method is suggested in this study. The effective pixel information of three channels can be concentrated in one intensity channel by converting color images from RGB to HSI, which decreases the null domain steganography algorithm's time and space complexity. In the meantime, a successful quantum steganography circuit is created. The simulation and numerical analysis results show that the algorithm has good invisibility, security, and robustness. [ABSTRACT FROM AUTHOR]

This paper is devoted to selecting rules for one-dimensional (1D) totalistic cellular automaton (TCA). These rules are used for the generation of pseudorandom sequences, which could be useful in cryptography. The power of pseudorandom number generator (PRNG) based on nonuniform TCA can be improved using not only one rule but a large set of rules. For this purpose, each subset of rules should be analyzed with its assignation to cellular automaton (CA) cells should be analyzed. We examine each of the subsets of totalistic rules, consisting of rules with neighborhood radius equal to 1 and 2. The entropy of bitstreams generated by the nonuniform TCA points out the best set of rules appropriate for the TCA-based generator. The paper also presents the method of simple selection of CA rules based on a cryptographic criterion known as a balance. The proposed method selects a maximal size of the set of available CA rules for a given neighborhood radius and suitable for PRNG. The method guarantees to avoid conflicting assignments of rules resulting in the creation of unwanted stable bit sequences, and provides high-quality pseudorandom sequences. This technique is used to verify the subsets of rules selected experimentally. Verified rules are proposed for 1D TCA-based PRNG as a new subset of best nonuniform TCA rules. New picked, examined, and verified subset of rules could be used in TCA-based PRNG and provide cryptographically strong bit sequences and huge keyspace. [ABSTRACT FROM AUTHOR]

This paper presents a novel encryption method based on individual block ciphering using Catalan random walks. This paper aims to offer some new possibilities of multimedia data protection to realize the rights of participants in the multimedia distribution chain (image, text, video, sound). Also, the emphasis is on advanced analysis of Catalan numbers and their combinatorial representations in multimedia security. The proposed method consists of five phases: conversion, division, selection, encryption, and generation. We presented the application of our method in ensuring the security of multimedia content. The proposed method was implemented in Java. In the experimental testing, we provide the time and space complexity of Catalan keys generation and Maurer's universal statistical test for the proposed method. Also, we state security analysis using machine learning methods and comparative analysis with existing methods of encrypting data into a blockchain. [ABSTRACT FROM AUTHOR]

Directional Modulation (DM) techniques provide wireless communication security against passive eavesdropping by means of specific physical layer characteristics. The original symbol constellations are transmitted along pre-specified spatial direction of legitimate users, while phase-amplitude distorted symbols are transmitted along the undesired directions of eavesdropper. In this paper, a comprehensive review of DM techniques and the most recent developments in this area are discussed. An analysis from three independent Physical Layer Security (PLS) viewpoints; communications, information-theoretic and cryptographic perspective is presented. Different performance metrics in literature are compared and the need for unified PLS approach is emphasized. As DM techniques constitute a relatively new class of PLS, there is no systematic organization of these techniques so far. This paper presents a classification framework for DM comprising of two main categories; angular (1D) and range-angular (2D) techniques. The former secures data along angular direction of physical space, while the latter provides security within certain range (distance) from the transmitter along desired angular direction. Further sub-categorization is based on the under-lying physical layer parameters exploited to achieve security, i.e. space, time, frequency, phase and polarization. The proposed framework is generic, flexible and extend-able to future research. In the end, limitations of existing techniques are pointed out and research directions are suggested. [ABSTRACT FROM AUTHOR]