The aim of the research presented in this thesis is to investigate the use of various optimisation heuristics in the fields of automated cryptanalysis and automated cryptographic function generation. These techniques were found to provide a successful method of automated cryptanalysis of a variety of the classical ciphers. Also, they were found to enhance existing fast correlation attacks on certain stream ciphers. A previously proposed attack of the knapsack cipher is shown to be flawed due to the absence of a suitable solution evaluation mechanism. Finally, a new approach for finding highly nonlinear Boolean functions is introduced.

Цель работы: разработка концепции эффективной системы учета и отслеживания продукции, основанной на применении блокчейн-технологии, в связи c изменениями в маркировке табачной продукции. Задачи работы: - изучить принципы блокчейн технологий; - изучить принципы «smart-контракта» технологии; - рассмотреть преимущества и недостатки технологии; - разработать smart-контракт; - оценить экономическую эффективность проекта. Объект исследования – блокчейн-технологии. Предмет исследования - процесс маркировки продукции. В первой главе приведен обзор теоретического материала по технологии блокчейн. Вторая глава посвящена разработке методики использования «smart-контракта» при маркировке табачной продукции. В третьей главе рассмотрено применение смарт - контракта для конкретного бизнес-процесса. Результаты работы: практическим результатом работы является концепция умного контракта, который существенно упростит процесс, а также позволит маркировать продукцию и контролировать сбыт. / The main objective is to develop the concept of effective system accounting and product tracking, based on using of blockchain system, due to changes in the labeling of tobacco products. Tasks of this research: - to examine principles of technology blockchain system - to examine principles of “Smart contract” technology - to consider the advantages and disadvantages of technology -to develop a smart contract - to examine the economical efficient of this project The object of this research is block-technology. The subject of the study is the process of labeling products. The first chapter provides an overview of theoretical material of blockchain technology. The second chapter is devoted to developing a methodology of using a "smart contract" for the labeling of tobacco products. The third chapter deals with the application of a smart contract for a particular business process The result of this Project: the practical result of the work is the concept of a smart contract, which will greatly simplify the process and will also allow to label products and control sales.

Cryptographic hash functions are an important tool in cryptography to achieve certain security goals such as authenticity, digital signatures, digital time stamping, and entity authentication. They are also strongly related to other important cryptographic tools such as block ciphers and pseudorandom functions. The standard and widely used hash functions such as MD5 and SHA-1 follow the design principle of Merkle-Damgard iterated hash function construction which was presented independently by Ivan Damgard and Ralph Merkle at Crypto'89. It has been established that neither these hash functions nor the Merkle-Damgard construction itself meet certain security requirements. This thesis aims to study the attacks on this popular construction and propose schemes that offer more resistance against these attacks as well as investigating alternative approaches to the Merkle-Damgard style of designing hash functions. This thesis aims at analysing the security of the standard hash function Cellular Authentication and Voice Encryption Algorithm (CAVE) used for authentication and key-derivation in the second generation (2G) North American IS-41 mobile phone system. In addition, this thesis studies the analysis issues of message authentication codes (MACs) designed using hash functions. With the aim to propose some efficient and secure MAC schemes based on hash functions. This thesis works on three aspects of hash functions: design, cryptanalysis and applications with the following significant contributions: * Proposes a family of variants to the Damgard-Merkle construction called 3CG for better protection against specific and generic attacks. Analysis of the linear variant of 3CG called 3C is presented including its resistance to some of the known attacks on hash functions. * Improves the known cryptanalytical techniques to attack 3C and some other similar designs including a linear variant of GOST, a Russian standard hash function. * Proposes a completely novel approach called Iterated Halving, alternative to the standard block iterated hash function construction. * Analyses provably secure HMAC and NMAC message authentication codes (MACs) based on weaker assumptions than stated in their proofs of security. Proposes an efficient variant for NMAC called NMAC-1 to authenticate short messages. Proposes a variant for NMAC called M-NMAC which offers better protection against the complete key-recovery attacks than NMAC. As well it is shown that M-NMAC with hash functions also resists side-channel attacks against which HMAC and NMAC are vulnerable. Proposes a new MAC scheme called O-NMAC based on hash functions using just one secret key. * Improves the open cryptanalysis of the CAVE algorithm. * Analyses the security and legal implications of the latest collision attacks on the widely used MD5 and SHA-1 hash functions.

Le routage et la gestion des clés sont les plus grands défis dans les réseaux de véhicules. Un comportement de routage inapproprié peut affecter l’efficacité des communications et affecter la livraison des applications liées à la sécurité. D’autre part, la gestion des clés, en particulier en raison de l’utilisation de la gestion des certificats PKI, peut entraîner une latence élevée, ce qui peut ne pas convenir à de nombreuses applications critiques. Pour cette raison, nous proposons deux modèles de confiance pour aider le protocole de routage à sélectionner un chemin de bout en bout sécurisé pour le transfert. Le premier modèle se concentre sur la détection de noeuds égoïstes, y compris les attaques basées sur la réputation, conçues pour compromettre la «vraie» réputation d’un noeud. Le second modèle est destiné à détecter les redirecteurs qui modifient le contenu d’un paquet avant la retransmission. Dans la gestion des clés, nous avons développé un système de gestion des clés d’authentification et de sécurité (SA-KMP) qui utilise une cryptographie symétrique pour protéger la communication, y compris l’élimination des certificats pendant la communication pour réduire les retards liés à l’infrastructure PKI. / Routing and key management are the biggest challenges in vehicular networks. Inappropriate routing behaviour may affect the effectiveness of communications and affect the delivery of safety-related applications. On the other hand, key management, especially due to the use of PKI certificate management, can lead to high latency, which may not be suitable for many time-critical applications. For this reason, we propose two trust models to assist the routing protocol in selecting a secure end-to-end path for forwarding. The first model focusses on detecting selfish nodes, including reputation-based attacks, designed to compromise the “true” reputation of a node. The second model is intended to detect forwarders that modify the contents of a packet before retransmission. In key management, we have developed a Secure and Authentication Key Management Protocol (SA-KMP) scheme that uses symmetric cryptography to protect communication, including eliminating certificates during communication to reduce PKI-related delays.