4,933 research outputs found
Trade-offs in Post-Quantum Cryptography: A Comparative Assessment of BIKE, HQC, and Classic McEliece
No full textThis study investigates the trade-offs inherent in three prominent post-quantum cryptographic algorithms: BIKE, HQC, and Classic McEliece. The evaluation of these algorithms was carried out across three different levels of security (L1, L3, and L5), centered on two crucial aspects: cryptographic size parameters and performance efficiency. Classic McEliece emerged as a space-demanding algorithm with significantly larger key sizes but managed to maintain relatively small ciphertext sizes. Conversely, HQC and BIKE presented smaller key and ciphertext sizes, indicating their potential suitability for applications with strict size constraints. In terms of computational costs, Classic McEliece required substantial resources for key generation, whereas HQC and BIKE exhibited balanced performance profiles. The findings underscore the importance of context-specific considerations when choosing an appropriate post-quantum cryptographic algorithm, highlighting the varying strengths and limitations of the analyzed algorithms
Evaluating Hashing Algorithms in the Age of ASIC Resistance
No full textIn the intricate matrix of cryptographic hashing, two contrasting paradigms vie for precedence: computational swiftness and resilience against specialized hardware, or ASICs. This study undertakes a meticulous exploration into these dueling priorities, juxtaposing conventional stalwarts like SHA-2 and KECCAK against the newer, ASIC-resistant X series. Leveraging detailed performance metrics and visual analytics, we discern the manifest advantage of SHA-2 and KECCAK in terms of computational alacrity. However, as the paper delves deeper, a compelling narrative unfolds. The deliberate design intricacies of the X series, despite their computational latency, emerge as robust bulwarks against potential centralization threats posed by ASIC miners. These algorithms embody a strategic deceleration, ensuring that the cryptocurrency terrain remains hospitable to a broad diaspora of miners. Through this multifaceted lens, we argue that in the cryptographic domain, raw speed is but one facet of a larger, more nuanced picture. The underlying ethos of decentralization and democratic access must guide our trajectory, even if it comes at the expense of pure efficiency. In essence, this paper endeavors to navigate the delicate balance between rapid computation and the overarching principles of an inclusive digital realm
Messor incorruptus Kuznetsov-Ugamsky 1929
No full textMessor incorruptus Kuznetsov-Ugamsky, 1929 West Iran Det. Radchenko ALIPANAH (2004), HMIMPublished as part of Paknia, O., Radchenko, A. & Alipanah, H., 2008, A preliminary checklist of the ants (Hymenoptera: Formicidae) of Iran., pp. 151-159 in Myrmecologische Nachrichten 11 on page 15
Backlund transformations for many-body systems related to KdV
No full textWe present Backlund transformations (BTs) with parameter for certain classical integrable n-body systems, namely the many-body generalised Henon-Heiles, Garnier and Neumann systems. Our construction makes use of the fact that all these systems may be obtained as particular reductions (stationary or restricted flows) of the KdV hierarchy; alternatively they may be considered as examples of the reduced sl(2) Gaudin magnet. The BTs provide exact time-discretizations of the original (continuous) systems, preserving the Lax matrix and hence all integrals of motion, and satisfy the spectrality property with respect to the Backlund parameter
Anatoly Kuznetsov, Author of Babi Yar: The History of the Book and the Fate of the Author
No full textThis Introduction to the special issue devoted to Anatoly Kuznetsov, author of Babi Yar: A Document in the Form of a Novel, dwells on the different aspects of the book’s importance, surveys the life of the author as intertwined with the history of this book, suggests a way of reading his other work in the light of Babi Yar, and notes the contributions of the articles collected in this issue
New technique for data hiding in cover images using adaptively generated pseudorandom sequences
No full textThe technology of direct spectrum spread is used in radio communication systems with multiple access. It is based on the use of pseudorandom (noise-like) discrete signals (sequences). In this paper steganography techniques based on spectrum spread are studied. Using noise-like signals, it is possible to hide information in cover images. We conduct experimental studies and show that the error rate in the restored informational messages is very high. This is due to the high correlation of discrete sequences and cover images. We offer a new technique when the statistical properties of cover images are taken into account when forming sequences. Our experiments show that the practical use of this approach can significantly reduce the error rate. The distortion of the image does not increase
Methods of Evaluation and Comparative Research of Cryptographic Conversions
No full textThe security of decentralized systems built on Blockchain technology is directly determined by the efficiency of the applied cryptographic transformations. Classical blockchain technology mainly uses several cryptographic primitives: hash function, electronic signature, encryption, etc. In particular, the hash function is used for several purposes as the generation of an address or user ID; hashing of transactions and blocks to confirm the indisputable block against network errors, as well as the hash value of the previous block is used as a reference in the formation of the next. The use of digital signatures in the blockchain system introduces services for the integrity and integrity of transactions. In turn, in any blockchain system there is a pool of transactions, each of which must be signed. This ensures that the transaction will not be altered, the signature of the transaction ensures that it is signed by a person who can then be identified, and, in fact, the signature can help determine “whether the user has the right to conduct the transaction.” Block ciphers are one of the most common cryptographic primitives, which is also used as a structural element of hash functions, message authentication codes, and so on. Thus, for the operation of monitoring and tracking programs using Blockchain technology, it is necessary to study various cryptographic primitives, in particular, hash functions, electronic signatures, encryption schemes, etc
Particle Swarm Optimization based on S-Boxes Generation
No full textThe generation of nonlinear substitutions (S-boxes) is an important task in the design of modern symmetric cryptoalgorithms. Various cryptographic properties of S-boxes (nonlinearity, balance, delta-uniformity, correlation and algebraic immunity, etc.) characterize their resistance to linear, differential, algebraic and other cryptanalysis methods. This article explores a computational particle swarm optimization (PSO) method as applied to the problem of generating nonlinear substitutions. Having a set of possible solutions (particles) and moving these particles in the search space, the PSO tries to improve the possible solution in terms of some quality indicator. We use nonlinearity, balance, delta uniformity, algebraic immunity and linear redundancy as the main indicators, and randomly generated S-boxes are used as a set of particles. This article shows several PSO modifications for generating nonlinear substitutions. At first, we reproduce the previously known PSO modification for generating S-boxes and show its low efficiency. At second, we propose our own PSO implementation and show that this method can actually generate substitutions with high cryptographic properties. The experimental results allow us to establish the influence of the size of the population of particles and the number of iterations of the outer loop on the efficiency of the heuristic generation of nonlinear substitutions. In addition, we explore the similarity of the generated substitution tables with the AES cipher S-box
Data hiding scheme based on spread sequence addressing
No full textModern information technologies are constantly being evolved. On the one hand, this leads to the qualitative improvement in the services provided. On the other hand, this fact leads to the emergence of new threats to information security. In particular, new technologies for hiding data carry additional risks of computer security, for example, through the possible introduction of malicious computer programs. This article discusses the techniques for hiding data in cover images using direct spread spectrum. We propose a new technique that implies directly addressing to the propagation sequence. On the one hand, it significantly reduces cover file distortion. But on the other hand, the error rate in recovered messages does not increase. Our experiments have shown, that Spread Spectrum Steganography technique indeed reduce the distortion in cover images compared to other techniques. We give some illustrative examples and show the advantages of the proposed method. Even with a significant increase in encoding density, the quality of cover images does not degrade. We also conduct experiments and evaluate image quality based on Mean Squared Error (MSE) and Peak Signal-to-Noise Ratio (PSNR). The obtained results of experimental studies confirm the adequacy and reliability of the research results. The main disadvantage of the proposed data hiding technique is the high computational complexity. To recover messages, it is necessary to sequentially calculate the correlation coefficients with a large number of pseudo-random sequences
Overview and Comparison of the Main Approaches to the Implementation of Contact Tracing Mechanisms in the COVID-19 Pandemic
No full textThe spread of the COVID-19 pandemic poses new challenges and threats to the international community. In particular, today the number of people infected with coronavirus infection already exceeds 80 million, almost 2 million died from the pandemic, and these terrible statistics are not final. Under these conditions, quarantine restrictions are almost the only effective means of counteracting the effects of the epidemic by reducing the rate of virus spread. However, quarantine restrictions have extremely serious consequences for the world economy, they have already led to a significant reduction in production and, consequently, jobs in almost all sectors of the economy. Therefore, the development and implementation of the latest information technologies for contact tracking in the context of the COVID-19 pandemic is an extremely important and urgent task. The purpose of this article is to research and substantiate various information technologies (such as Bluetooth, Wi-Fi, GPS, etc.) in contact tracking tools to prevent the spread of infectious diseases. We analyze different approaches to the implementation of contact tracing mechnisms, highlight their advantages and disadvantages as well as opportunities for improvement. Also we analyze examples of real applications of the advanced countries functioning at the state level
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