Lightweight encryption algorithms are considered a relatively new direction in the development of private key cryptography. This need arose as a result of the emergence of a large number of devices with little computing power and memory. Therefore, it became necessary to develop algorithms that can provide a sufficient level of security, with minimal use of resources. The paper presents a new lightweight LBC encryption algorithm. LBC is a 64–bit symmetric block algorithm. It supports 80 bit secret key. The number of rounds is 20. The algorithm has a Feistel network structure. The developed lightweight algorithm has a simple implementation scheme, and the transformations used in this algorithm have good cryptographic properties. This was verified by studying the cryptographic properties of the algorithm using the "avalanche effect" and statistical tests. The avalanche property was checked for each round when each bit of the source text was changed. Based on the work carried out, it was found that the proposed encryption algorithm is effective to ensure a good avalanche effect and the binary sequence obtained after encryption is close to random. Its security against linear and differential cryptanalysis is also evaluated. The results of the research revealed good cryptographic properties of this algorithm. The algorithm will be used for devices with small hardware resources, in information and communication systems where confidential information circulates, and it is also extremely necessary to exchange information in a protected form in an operationally acceptable time

This paper examines the properties of classical secret sharing schemes used in information protection systems, including the protection of valuable and confidential data. It addresses issues such as implementation complexity, limited flexibility, vulnerability to new types of attacks, the requirements for such schemes, and analyzes existing approaches to their solutions. A new secret sharing scheme is proposed as a potential solution to these challenges. The developed scheme is based on multivariable functions. The shares distributed among participants represent the values of these functions. Secret reconstruction is reduced to solving a system of linear equations composed of such functions. The structure and mathematical foundation of the scheme are presented, along with an analysis of its properties. A key feature of the proposed scheme is the incorporation of functions aimed at authenticating participants and verifying the integrity of the distributed shares. The paper also provides a cryptanalysis of the scheme, evaluates its resistance to various types of attacks, and discusses the results obtained. Thus, this work contributes to the advancement of information security methods by offering a modern and reliable solution for the secure storage and joint use of secret data.

This research paper is aimed at studying the generation of round keys (GRK) of the lightweight block cipher (LBC), which provides an optimal balance between security, performance, and minimal costs in internet of things (IoT). For comparative analysis, the GRK of the well-known PRESENT algorithm was studied. A number of studies have been carried out to assess the cryptographic strength of encryption algorithms, however, less attention has been paid to the assessment of the reliability of GRK algorithms, which can lead to a possible weakening of a cryptosystem. A trusted GRK should issue random and independent round keys regardless of the secret key. The experiments were carried out with secret keys of low and high density, as well as random numbers. The obtained results show that the GRK of the LBC algorithm generates random round keys that successfully pass tests of the National Institute of Standards and Technology (NIST) for randomness.

Cryptographic technologies that have become widespread in the world are inex- tricably linked to the issues of secure storage, use of keys, and key exchange. Often, insecure key management reduces the quality of even exceptionally good systems, since the security of the algorithm is concentrated mainly in the key. This paper proposes a key management model in cryptographic systems. The model is based on creating a unified key database for all users. This database is filled with keys of a certain length, which are generated using a pseudo-random sequence generation algorithm.

К пост-квантовым криптосистемам относятся криптографические системы, способные противостоять атакам с использованием квантовых компьютеров. Надежность этих систем основывается на отсутствии эффективных алгоритмов атаки даже при их выполнении на квантовых компьютерах. В данной работе предлагается новая схема пост-квантной подписи Syrga2, основанная на хеш-функциях. Как известно, существующие пост-квантовые алгоритмы делятся на классы в зависимости от их структуры. Предлагаемая схема Syrga2 относится к классу подписей многократного применения с сохранением состояния. Отличительной чертой подписей, сохраняющих состояние, является достижение компромисса между производительностью и размером подписи. Данная схема представляет возможность создания безопасной подписи для r сообщений с помощью одной пары секретного и публичного ключа. Стойкость алгоритмов подписи, основанных на хеш-функциях, зависит от свойств используемой в их структуре хеш-функции. Кроме того, для таких алгоритмов удается точно указать уровень безопасности. В предлагаемой схеме в качестве хеш-функции используется алгоритм HBС-256, разработанный в Институте информационных и вычислительных технологий (ИИВТ). Безопасность алгоритма HBС-256 тщательно изучена в других работах авторов. В отличие от схемы Syrga1, представленной в предыдущих работах авторов, схема Syrga2 предусматривает определение разного уровня безопасности, задаваемого параметром τ. В данной работе экспериментальным образом показана невозможность взлома предложенной схемы с использованием атаки на основе подобранного открытого текста (chosen-plaintext attack). Кроме того, оценивается производительность схемы при создании подписи, подписании и верификации сообщения.

The rapid development of the Internet of Things (IoT) and embedded systems necessitates cryptographic solutions tailored for resource-constrained devices. Lightweight cryptography provides a balance between security, performance, and low power consumption, which makes it suitable for sensors, RFID tags, medical devices, and other IoT components. However, in practice, such algorithms are vulnerable to side-channel attacks that exploit leakage of power consumption, electromagnetic emissions, or timing characteristics to recover secret keys. The most threatening among them are differential and correlation power analysis techniques, which can compromise an implementation with a relatively small number of measurements. This article presents an overview of side­channel attacks targeting lightweight algorithms such as PRESENT, SIMON, SPECK, and PRINCE. Key protection techniques are examined, including masking, hiding, operation shuffling, threshold implementations, and hardware countermeasures. A comparative analysis of their effectiveness and overhead is provided, highlighting the strengths and weaknesses of each approach. Particular attention is given to the practical applicability of protective mechanisms under the resource constraints of IoT devices. The results demonstrate that no single countermeasure is universal; the most effective solutions are combined approaches that integrate masking with hiding techniques. The study emphasizes the need for further research aimed at developing robustness evaluation methodologies and improving protective mechanisms for lightweight cryptography.