Radiotekhnika

Research into methods and algorithms for generating (pseudo) random sequences over an arbitrary alphabet

I.D. Gorbenko — 2024-03-20

Randomness is an integral component of most special software and hardware CIP tools. Work and development towards improving the process of randomness generation is actively underway and requires special attention.

This paper is devoted to the research into algorithms for generating (pseudo)random sequences over an arbitrary alphabet, estimating their complexity (time and capacity), as well as statistical characteristics. This study is important because modern post-quantum algorithms use such sequences to generate keys and random components of digital signatures and key encapsulation.

Obtained results can serve as a motivation for choosing an algorithm for generating sequences of an arbitrary alphabet for use in certain cryptographic transformations or algorithms.

Methods and means for analysing, evaluating and comparing properties of random sequences and random numbers

D.Yu. Holubnychiy — 2024-03-20

Methods and means for analysing, assessing and comparing properties of random sequences and random numbers are considered in the work. The article also discusses such aspects as mathematical modeling of random processes, statistical methods for estimating distribution parameters, comparative analysis of the properties of random variables. To date, random sequences (RS) and random numbers (RN), produced by physically real (PT RNG) and non-physically real (NPT RNG) generators, are widely used in practice, they essentially legislate key generation mechanisms in cryptographic systems. Depending on the cryptographic transformations, they are used to generate long-term keys and session keys of symmetric cryptographic transformations, long-term asymmetric key pairs and session key pairs, general parameters of cryptographic transformations and cryptographic protocols, specific one-time values (nonces), challenges (challenges), blinding and masking values, etc. Among the set of requirements for such generators is the provision of the maximum possible value of the initial entropy in a number of, and possibly most, cryptographic applications. The analysis of international and national legal documents regarding the requirements for PT RNG and NPT RNG sources and, accordingly, generators, carried out in the work showed that they, taking into account the significant challenges associated with expanding the possibilities of cryptanalysis based on application, in addition to classical, quantum and side channel attacks should be significantly improved and evaluated using complex methods using a system of unconditional criteria. The purpose of this article is to substantiate, develop and confirm experimentally the correct application of RS and RN generation algorithms based on PTRNG and NPTRNG, including in the application of classical and quantum microelectronics, as well as the development of recommendations for their use for generating keys and parameters for quantum stable methods and standards of cryptographic transformations.

Modern threats to information and communication systems and methods of protection against them

O.I. Peliukh — 2024-03-20

In the modern world, information and communication systems (ICS) have become an integral part of our lives, processing, storing and transmitting information. However, this dependence makes them extremely vulnerable to various threats. The article examines the current threats that call into question the normal functioning of ICS. The authors emphasise the constant evolution of these threats, which makes them more complex and dangerous. This necessitates constant research and development of new methods and means of information protection, as well as raising awareness of ICS users about cyber threats. The purpose of the article is to study modern ICS threats and develop recommendations for improving the level of information security (IS). The article provides a classification of ICS IS threats by various criteria: by the basic principles of the cybersecurity triad (confidentiality, integrity and availability), by sources of threats (internal and external), by the amount of damage caused (from general to private), by the degree of impact (passive and active) and by the nature of occurrence (natural and artificial). The article reveals the sources of threats to ICS security: unintentional (related to user errors, software failures or hardware failures) and intentional (cyber-attacks aimed at causing damage to ICS). Particular attention is paid to cyberattacks that are becoming more widespread. The authors describe different types of cyberattacks, as well as methods and means of their implementation. An important aspect of the article is the development of recommendations for improving the level of security. Along with the technical aspects of protection, the article considers the importance of implementing organisational measures such as security policy, access control and privilege management. The article also draws attention to the importance of complying with international and national standards for the protection of information in ICS. These measures help to avoid leakage or prevent unauthorised access to valuable information.

Comparative analysis of Ukrainian and foreign banking applications

Y.O. Lohachova — 2024-03-20

Mobile banking applications have been actively used in the financial sector for several years. Such applications significantly facilitate the use of banking services for their users. At the time of active digitalisation, the financial sector also needed reforms and active changes, that is why developers have been actively working on creating first home banking and then mobile banking applications since the end of the last century. Mobile banking applications have come a long way in evolution, so that users can now perform not only simple banking operations, but also many new additional functions making life easier. The development of the technologies used has also led to the emergence of new vulnerabilities, which required the improvement of security systems in such applications. The development path and experience of Ukrainian applications is somewhat different from that of foreign ones, but no less valuable. The development of foreign applications is more standardised and controlled by the government. Such solutions allow for better verification of compliance with security requirements. However, it should not be forgotten that mobile banking was created to facilitate financial transactions remotely, and therefore it should be easy to use by the average user. The article provides a comparative analysis of Ukrainian and foreign banking applications, including: Stanford FCU, Fideuram, N26, Banque populaire du nord, Sparkasse, Monobank, Privat24, Ukrsib-online, Oschadbank, and PUMB. The applications were compared by two groups of criteria, namely security and convenience criteria. The article focuses not only on the aspects in which Ukrainian applications should develop, but also on those in which they have an advantage over foreign apps.

Research horizons in group cryptography in the context of post-quantum cryptosystems development

Y. Kotukh — 2024-03-20

Asymmetric cryptography relies on the principle of ease of calculation and complexity of one-sided functions’ inversion. These functions can be easily implemented, but inverting them is computationally difficult. In this context, NP-complete problems are ideal candidates for the role of such functions in asymmetric cryptography, since generating their cases is easy, but finding solutions is difficult. However, the practical application of NP-complete problems has certain limitations, in particular due to difficulties in creating problems that would be complex on average. Although an NP-complete problem may be hard in general, a particular case of it may be solvable, making it unsuitable for cryptography. The article considers classes of NP problems. Basic definitions and concepts are given. The properties of the class of NP-complete problems, the conditions for determining belonging to the set of NP-complete problems, and the current state of difficult to solve problems are analyzed. It turns out that the class of NP-complete problems is hard for quantum computing. The criteria for belonging of the word problem in groups to NP-complete problems are analyzed. Finite non-Abelian groups are defined for which the word problem is NP-complete. The advantages of using non-Abelian groups for cryptographic applications are considered. The rules of change of form, which determine the transformation of equivalent words, are given. The word problem in finite groups is one of the NP-complete problems. The latest research and prospects for the development of cryptographic primitives of asymmetric cryptography using difficult-to-solve problems in finite groups are analyzed.

Assessment of the localization error of radio-acoustic bug devices by means of acoustic distance measurement

A.N. Oleynikov — 2024-03-20

Localization of a radio-acoustic bug device (RABD) is the determination of its location in space. Localization of the RABD can be carried out both by the electromagnetic field and by using acoustic probing signals.

Localization using acoustic probing signals is carried out using an acoustic rangefinder (AR) as part of a hardware-software complex (HSC) for detecting RABD (for example, the «ORT», «VOSTOK» hardware systems developed at KNURE). The operating principle of AR is given in the article.

The error in measuring the coordinates of the RABD with an acoustic rangefinder consists of instrumental and random errors in measuring the range, as well as the methodological error in determining the location of the RABD, which is due to the peculiarities of the rangefinder method of determining coordinates.

The article addresses the issue of minimizing the error in measuring the range of a bug device with an uncertainty of location by analyzing various methods for fixing the temporary position of an acoustic signal in real conditions for detecting radio-acoustic embedded devices in designated premises.

The advantages and disadvantages of various methods for fixing the time position of an acoustic signal along one of the pulse fronts are analyzed simultaneously on the leading and falling edges of the pulse, at the position of the maximum signal values and using the correlation method of fixing the time position of the signal in relation to the localization of radio-acoustic bug devices in real conditions. The results of mathematical modeling and experimental research using the HSC “VOSTOK” of the error in determining the range to a radio-acoustic bug device are presented.

It has been established that when localizing bug devices using an acoustic range finder, it is advisable to use the correlation method of fixing the time position of pulses. At the same time, there is a decrease in the standard deviation of the localization error compared to the threshold method by 15% in the range of s/n values from 2 to 20, high stability of the results and low sensitivity to changes in the amplitude of the received signal.

Software and hardware complex based on the STM32F407VG microcontroller for studying vibrations with the LIS3DSH accelerometer

V.V. Semenets — 2024-03-20

The statement of the problem of building a software-hardware complex based on the STM32F407VG microcontroller for studying vibrations with the LIS3DSH accelerometer is given.

A physical model of the system, including a microcontroller, three-axis digital LIS3DSH accelerometer, was designed and implemented, which is characterized by a low price of the technical solution. The interaction between the microcontroller and the accelerometer occurs through the SPI interface.

Specialized software of the system was developed and implemented, it includes a driver for setting up, collecting and processing data from the accelerometer and a corresponding software for plotting graphs of vibro acceleration signals in the time and frequency domains. The built-in software enables you to implement extensive functionality and is free to use.

The built system makes it possible to analyze vibration parameters in order to predict and prevent possible accidents, reducing the costs associated with the failure of expensive parts and components.

Early warning model of cyber threats in 5G networks using Markov processes

Y.Y. Kolyadenko — 2024-03-20

Security of telecommunication networks, in which the transmission channel can be used by many users simultaneously, is a particularly important problem. In wireless metropolitan networks, this problem is compounded by the fact that the communication channel is publicly available. In other words, information transmitted in such networks can be easily intercepted by intruders. This can lead to theft of personal data, financial losses, or even to a breach of security of critical infrastructure.

Information security can be compromised by failures that affect the availability, integrity, or confidentiality of information. These failures can be caused by vulnerabilities, namely, defects in software or hardware that can be exploited by attackers to gain unauthorized access to information. Information security is one of the components of 5G networks reliability. The main security threat to such systems is vulnerabilities, primarily of software components. Despite the fact that information about vulnerabilities of software products is publicly available, there is not enough data to quantify the security of these products using a single general criterion. It is also impossible to predict how well they will be protected from attacks in the future. One of the main problems of choosing the most secure 5G configuration is the difficulty in quantifying the level of information security. In addition, it is difficult to choose adequate evaluation indicators that take into account all the factors affecting successful network penetration and the amount of potential damage.

The search for vulnerabilities in software components is an urgent and resource-intensive task that has recently been taken up by large companies and research centers. Analysis of vulnerability detection and remediation processes shows that they can be described by a mass service system with an infinite queue length.

A model for early warning of cyber threats in 5G networks using Markov processes has been developed. Using simulation modeling in the Matlab environment, a time diagram of the arrival of requests for vulnerability detection was obtained. The change in the probabilities of states was also obtained. Thus, knowing the intensity of the flows, it is possible to model and predict the processes of the arrival of requests for vulnerability detection in real time.

Features of voice traffic transmission using IEEE 802.11ac wireless networks

V.S. Lazebnyi — 2024-03-20

The purpose of the research is to find out the features of voice traffic transmission for the organization of IP telephony service in office premises using the IEEE 802.11ac network to ensure the high-quality provision of the specified service for a sufficiently large number of users even in the case of intensive transmission of a mixed traffic. The analytical study is based on traditional probabilistic approaches to evaluating the operational characteristics of wireless networks of the 802.11 standard. The 802.11ac network with a channel bandwidth of 20 MHz in the mode with one spatial stream was studied. In the specified network, a scenario was considered in which, for the provision of IP-telephony services, prioritization was carried out in accordance with the IEEE 802.11e specification, with AC_VO priority given to a voice traffic, and AC_BK priority to other data transmitted over the same network. It is mathematically substantiated that if there are stations in the IEEE 802.11ac network transmitting low-priority traffic of the AS_BK class, even under saturated load conditions, the simultaneous operation of a large number of stations transmitting voice traffic is possible. Estimates of the effect of frame sizes of low-priority traffic, as well as the impact of collisions on conditions of voice traffic transmission are obtained. The work uses an original method of studying the conditions of transmission of high-priority traffic in networks with a mixed load. The research results will be useful to specialists in the field of planning and maintenance of IEEE 802.11 wireless networks to ensure high quality indicators of voice services.

Ways to increase the EMF of semiconductor elements based on thermoelectric effects

O.V. Miagkyi — 2024-03-20

The paper examines the development of the thermovoltaic effect in varizone semiconductor multilayer structures. The effect of the occurrence of electromotive force (EMF) in semiconductor samples without isotype transitions and metal-semiconductor barriers when heated along the sample under the thermovoltaic effect is studied. The possibility of obtaining stable thermally stimulated EMF in semiconductor samples with a heterogeneous composition, in particular in varizone semiconductors when they are heated, is considered. A semiconductor with a heterogeneous composition is simulated, in which the concentration of charge carriers, both electrons and holes, is enough to excite a significant electric current. Cases of both a single varizone semiconductor layer and a combination of several layers under different temperature conditions are considered. Both the definition of the EMF and numerous process characteristics are analyzed. It is confirmed that the appearance of a thermo EMF is caused by the non-equilibrium state and heterogeneity of the environment, as well as its bipolarity. It is shown that in a closed circuit with heterogeneous doping and variable width under uniform heating of the entire circuit, the EFM appears. The equation that determines the EFM ratio in various semiconductors is received. A thermophysical model based on the nonstationary heat equation with boundary conditions of the 2nd and 3rd kind for thermal field calculations is developed. A thermophysical model is created that characterizes a two-layer structure with smoothly changing parameters. The results of the numerical experiment made it possible to obtain the recommended temperature limits for the operation of the considered elements taking into account the SiGe solid solution and to calculate the value of the additional EMF.

The role of oxygen in the process of modifying the state functionals of wheat seeds and lactobacilli by an electromagnetic field

O.I. Kovalenko — 2024-03-20

The possibilities to modify the functional characteristics of wheat seeds and lactobacilli using low-intensity electromagnetic fields (EMF) in frequency ranges associated with gas resonances are considered.

The objective of the work is to study the role of oxygen in the process of modifying the functional indicators of soft wheat seeds and lactobacilli strains state irradiating them with low-intensity EMF on the resonant absorption lines of oxygen, hydrogen and ozone, additionally enriching water with oxygen during its irradiation and subsequent soaking of seeds in it, and creating conditions for cultivating bacteria in an environment with normal and reduced oxygen content.

To carry out electromagnetic effect, generators G4-141 and G4-142 were used. The enrichment of water with oxygen occurred during its irradiation with EMF, after which wheat seeds were soaked in it. Microaerophilic conditions for the cultivation of bacteria in microanaerostats.

The role of oxygen influence on the vital activity of biological objects of different classes (wheat seeds and lactobacilli) is shown. The possibility of stimulating seed germination by indirect irradiation with oxygen-enriched water at the 61,0 GHz oxygen resonance absorption line with a short exposure of the signal is shown. It has been found that by irradiating lactobacilli in the frequency ranges of 42,2 and 61,0 GHz, they can stimulate their absorption of glucose when cultivated under aerobic conditions, which, in turn, helps to increase the rate of population development. The conditions under which increasing production of high molecular weight peptide fractions (presumably plantaricins) by L. Plantarum strain and decreasing the share of low molecular weight proteins in the nutrient medium occur, which indicates, accordingly, an increasing the antagonistic activity of the L. plantarum strain and an improvement in its absorption of nutrients, were defined.

The results obtained open up the prospect of using electromagnetic technologies in agriculture when preparing seeds for sowing and in medicine, in particular in the development of new generation drugs based on lactobacilli with increased colonization and antagonistic properties towards pathogens.

Methods for logical processing of images of radar objects marks based on semantic features

V. Zhyrnov — 2024-03-20

This paper considers a method for logical processing of radar images based on semantic features. Algorithms and programs for automatic detection and recognition of radar aerial objects in surveillance radars with processing of real signals recordings are also given. The relevance of this work is the development of automatic information processing algorithm to ensure effective detection and recognition of radar object signals based on semantic features. The advantage of this method is the possibility to bring the image processing procedure of radar object images closer to the expert’s logic. It implies involvement in analysis of various distinguishing features between reflections from aerial objects. The problem of detecting and recognizing images of radar objects is transformed into the problem of feature classification. Therefore, the essence of logical image processing method based on semantic features is a making decision about detection and recognition of radar objects based on comparative analysis of features, which are defined on the set of semantic, fluctuation, geometric and energy components of radar image. An algorithm for automatic decision-making on detection and recognition of aircraft radar signals, including point-moving and stationary aircraft such as airplanes, helicopters, UAVs, is given. This approach of forming semantic features of radar signals, as well as the automation of information processing operations, increases the effectiveness of detecting weak signals due to accumulation of signal (energy) and logical information. At the same time, logical information is accumulated from the analysis of dynamic map of radar signal intensities with tracking of changes occurring in it during several radar soundings.

Research of the angular distribution of errors at different transmission speeds in the decameter range

V.A. Bulaga — 2024-03-20

The paper states that the main factors that affect the reduction of bandwidth and reliability of communication channels in the decameter range are multiradiation and the level of interference from transmitters operating at close frequencies. It is known that one of the methods of combating such negative phenomena is the use of phased antenna arrays in communication systems. The paper evaluates the efficiency of the phased antenna system according to the information criterion "error coefficients – elevation angle". The angular distribution of errors at different transmission speeds in the short-wave range when using phased antenna arrays was studied according to the information criterion "error coefficients – angle of position". The results obtained in the work allow us to draw the following conclusions: the possibility of using error detection devices when testing the reliability of communication channels is fully confirmed communication of the decameter range; the use of controlled phased antenna arrays on the receiving side allows to solve a complex of trajectory tasks, and also allows to evaluate the effectiveness of communication systems that use beam distribution at the reception.

Evaluation of the quality of radar information of dependent cooperative surveillance systems

I.V. Svyd — 2024-03-20

The work demonstrates that cooperative surveillance systems occupy a significant place in the information support of the airspace control and air traffic control system. The issues of assessing the quality of radar information from dependent cooperative surveillance systems have also been studied. These systems are shown to be promising surveillance systems for air traffic control. Authors' attention is focused on the importance of ensuring the integrity of information of dependent surveillance systems. The objective of this work is to formalize models for assessing the probability of an erroneous alarm and integrity risk. According to the results of the study, it is shown that the difference in the coordinates of two independent measurements of the same aircraft position is greater than some predetermined value, and therefore the quality of the coordinate information of the dependent surveillance system under consideration is unsatisfactory and leads to a warning alarm for the dispatcher. It has been demonstrated that the integrity of the coordinate information of dependent surveillance systems determines the likelihood that information about the coordinates of the aircraft transmitted in messages from dependent surveillance systems and used by the dispatcher for air traffic control purposes does not contain undetected errors exceeding the threshold of the established holding radius.