With the increasing popularity of blockchain - the cryptocurrency technology, the decentralized potential of the Blockchain technique is driving a new wave across the manufacturing industry. This paper introduce how to use the blockchain technique as a tool for solving supply chain related tasks in manufacture industry, and drive quantum leaps in efficiency, agility and innovation comparing with traditional centralized management system. This paper introduces the blockchain technique with its value properties and the requirement of this technique from manufacture industry. It also presents a clear blockchain architecture based on manufacture industry supply chain management mechanism describing its characteristics, unique consensus algorithms, smart contracts, network, scalability, databases. The paper also gives out a practical supply chain Dapp upon this architecture. / I och med det ökande intresset för kryptovaluta-teknologin Blockchain, går decentraliseringen av Blockchain-tekniken som en ny våg över tillverkningsindustrin. Denna uppsats syftar till att introducera hur tekniken av blockchain kan användas som ett verktyg för att lösa problem relaterade till leverantörskedjan i tillverkningen. Den belyser även vilka fördelar tekniken har gällande effektivitet, flexibilitet och förnyelse jämfört med traditionella centraliserade styrningssystem. Arbetet presenterar fördelarna med blockchain och hur industrin är i behov av denna teknik. Uppsatsen presenterar även en tydlig blockchain konstruerad struktur baserad på tillverkningskedjans mekanism som består av unika algoritmer, nätverk och databaser. Ett praktiskt exempel på en decentraliserad applikation baserat på denna struktur ges även.

Объектом исследования являются блокчейн-технологии и децентрализованные сервисы. В данном исследовании предлагается разработать децентрализованное приложение для проведения лотерей. Исследование проводится с целью изучения блокчейн-технологий. Для разработки децентрализованного приложения использовался блокчейн Ethereum. В результате был разработан смарт-контракт для проведения лотерей, а также веб-интерфейс для взаимодействия с ним, образующие децентрализованное приложение. / The object of research is blockchain technologies and decentralized services. In this study, it is proposed to develop a decentralized application for conducting lotteries. The research is conducted in order to study blockchain technologies. The Ethereum blockchain was used to develop a decentralized application. As a result, a smart contract for conducting lotteries was developed, as well as a web interface for interacting with it, forming a decentralized application.

現行醫療保險理賠申請流程相當繁複，被保險人需要向醫療機構申請診斷證明，填具理賠申請書向保險公司提出理賠申請，再由保險公司進行審核。若遇到無法從診斷書直接審核之個案，保險公司需先取得被保險人簽署之調閱病歷同意書後，方能至醫療機構調閱病歷，以利後續理賠審核。這樣的流程，對保險公司來說，需耗費大量人工成本；對被保險人來說，則也有資訊不夠透明的疑慮。 區塊鏈的運作有著公開透明，且難以造假的不可否認性。智能合約是在區塊鏈平台上執行的協議落實程式，既能確保程式不會被竄改，又可保留所有執行紀錄。若能透過這些特性來做為醫療保險理賠傳遞訊息的媒介，除了能提昇保險公司審核流程的時效性，被保險人也能獲得公開透明的資訊。 本論文提出了一套基於智能合約來實現快速醫療保險理賠的方案，我們在以太坊上實作智能合約，我們的方案除了能改善現有的問題，也建構出一套公開透明，且兼顧病人隱私的理賠系統，並考量實際狀況，讓保險公司的業務邏輯可以重用，在理想與現實之間取得一個適當之平衡點。 / Current medical insurance claims application process is complex. It requires the insured to apply for medical diagnosis, and to fill out an application form to the insurance company. The insurance company then reviews the case. If they are unable to approve the claims, they must first obtain the consent form from the insured in order to access to his or her medical records to facilitate subsequent claims review. Throughout the process, the insurance company needs to pay a lot of labor costs; while the insured will have many concerns of information transparency. Blockchain operates in an open and transparent manner and maintains its data in a tamper-free way. Smart contracts are programs executed on a blockchain platform to enforce an agreement such that the program will not be tampered with, and all records of execution will be kept from modification. These characteristics of a smart contract make it very good as a tool for streamlining the medical insurance claims process, as it will greatly reduce the human efforts involved on the insurance company side while increase the information transparency from the perspective of the insured. This thesis presents a smart contract based solution for streamlining the medical insurance claims process. We design and implement the con-tract on the Ethereum platform. In addition to improving the existing problems, our solution builds an open and transparent claims system that takes into account the patient privacy and the practical requirement of re-using the existing claims processing system of the insurance company, thus achieving a proper balance between the ideal and reality.

Peer-to-peer (P2P) reputation systems, such as those used by eBay and Amazon, servean important role on the web, especially in E-commerce, as online reputation serves asa primary guiding factor for consumers in making informed decisions. The importanceof these systems, and also the increasing popularity of P2P and distributed systems, theissue of how to prevent and resist sybil and re-entry attacks becomes an important area ofresearch as they can impinge the integrity of those systems. To address this issue, in thisthesis, we propose an approach that encompasses a software architecture and processeswhich serves as a proof-of-concept of how to mitigate sybil and re-entry attacks on review based P2P distributed reputation systems. The architecture uses novel technologiessuch as blockchain, smart contracts, and non-fungible tokens (NFT) in conjunction withSwedish E-id provider BankID to build a sybil and re-entry attack resistant reputationsystem. To validate the feasibility of our approach, we developed a prototype and used itto run experiments to evaluate the functional correctness of the architecture as a mitigation solution

Purpose: In this study, areas of use of blockchain technology in transportation management will be discussed. The purpose is to contribute with theoretical research of advantages and disadvantages of blockchain technology in transportation management before an implementation at Rhenus Logistics.   Methodology: Through interviews and literature, ways of using blockchain in transportation management is researched. A case study is set up, to further analyze the research topic from the view of an individual third-party logistic company.  Findings: Results showed that for a third-party logistic provider to successfully use blockchain technology within transportation management, it is important to have the entire network onboard in the process. If so, functionalities such as track and trace, digital handling of paperwork and smart contracts could be used. The advantages of using blockchain technology for transportation management at Rhenus Logistics were found to be trust, transparency, traceability, efficiency, cost-saving opportunities and the use of smart contacts. Identified disadvantages for Rhenus Logistics was that blockchain is costly, stakeholders are hesitant to get involved, smart contracts are not considerate of blurry lines in real life practice and there is a challenge in finding an accurate blockchain design for their business model.

El sector agrícola empresarial peruano debe tener una infraestructura que no limite la comercialización de bienes entre los agricultores por la dependencia de un intermediario. Sin embargo, esta no es la realidad porque actualmente para realizar la compra o venta de un producto, se necesita de un intermediario para validar ciertas actividades. Una alternativa para reducir esta dependencia es el uso de herramientas web a través del internet para que los agricultores puedan ofrecer sus productos al mercado y los compradores tengan una mayor variedad para su elección; sin embargo, esto genera una gran preocupación en la población ya que existe una desconfianza por la falta de seguridad que esto conlleva. Smart Contract y Blockchain, son tecnologías emergentes que están surgiendo para ofrecer nuevas oportunidades para el diseño de mercados descentralizados, estos permiten incrementar la seguridad de las transacciones, ahorros al no depender de un intermediario, aumentar la confianza de los agricultores y mejorar el crecimiento del país. Este proyecto propone una modelo que utiliza las tecnologías Smart Contract y Blockchain aplicadas en el sector agrícola empresarial peruano, que permite tanto al comprador como al vendedor comercializar productos agrícolas. Los resultados de las empresas encuestadas y tres expertos fueron satisfactorios, muchas de las empresas han tenido buena aceptación según la encuesta realizada, el 50% de las empresas considera como “Muy aceptable” el modelo según las características mencionadas en la encuesta y el otro 50% como "Aceptable"; así mismo, los expertos validan el modelo de acuerdo a los casos de uso de Blockchain y la metodología Solium para verificar que los Smart Contract se definieron correctamente. / The Peruvian agricultural sector must have an infrastructure that does not limit the commercialization of goods among farmers by the dependence of an intermediary. However, this is not the reality because currently to make a purchase or sale of a product, you need an intermediary to validate certain activities. An alternative to reduce this dependence is the use of web tools through the internet so that farmers can offer their products to the market and buyers have a greater variety for their choice; however, this generates a great concern in the population since there is a distrust for the lack of security that this entails. Smart Contracts and Blockchain, which are emerging technologies that offer new opportunities for decentralized market designs, these allow to increase the security of the transactions, savings by not depending on an intermediary, increase the confidence of the farmers and improve the country's growth. This project proposes a model that uses Smart Contract and Blockchain technologies applied in the Peruvian agricultural business sector, which allows both the buyer and the seller to commercialize agricultural products. The results of the surveyed companies and three experts were satisfactory, many of the companies have had good acceptance according to the survey carried out, 50% of the companies consider the model as "Very acceptable" according to the characteristics mentioned in the survey and the other 50 % as "Acceptable"; Likewise, the experts validate the model according to the Blockchain use cases and the Solium methodology to verify that the Smart Contracts were defined correctly. / Tesis

Les contrats intelligents sont des programmes informatiques qui s’exécutent d’eux-mêmes dès lors que certaines conditions, déterminées au préalable par les parties, sont remplies. Ce type de contrat est récemment entré dans une nouvelle ère suite à la démocratisation des cryptomonnaies, notamment le Bitcoin et sa technologie sous-jacente ; la chaîne de blocs. Celle-ci se définit comme un registre virtuel répertoriant des historiques de transactions, permettant entre autres de réaliser des transferts d’actifs de pair à pair, sans intermédiaire. Désormais, la chaîne de blocs est aussi capable de servir de support au contrat intelligent, ce qui soulève de nouvelles problématiques juridiques. En raison de sa nature, il est possible que le contrat intelligent puisse causer un préjudice en cas de mauvaise ou de non-exécution. Le présent mémoire consiste à déterminer l’applicabilité du régime de responsabilité civile à ce type de contrat, au regard des dispositions du Code civil du Québec et de la Loi concernant le cadre juridique des technologies de l’information. / Smart contracts are computer programs that run on their own when conditions, previously determined by the parties, are met. This type of contract has recently entered a new era following the democratization of cryptocurrencies, especially Bitcoin and its underlying technology; the Blockchain. It’s a virtual register listing transaction history, making it possible, among other things, to carry out asset transfers from peer to peer without any intermediary. Now, the blockchain is also able to support smart contracts, which raises new legal issues. Due to its nature, it is possible that the smart contract may cause damage in case of bad or non-performance. The purpose of this paper is to determine the applicability of the civil liability regime to this type of contract, in light of the provisions of the Civil Code of Quebec and the Act to establish a legal framework for information technology.

Even when end-to-end encryption is used in centralized messaging services, problems related to security, privacy, availability, and transparency remain. These problems can be avoided or reduced by using a decentralized architecture. The most notable previous attempts at decentralized messaging protocols have been based on peer-to-peer or federated networks. In a federated network, anyone can run servers that clients interact with and that interoperates with other servers in the network, whereas there is no distinction between clients and servers in a peer-to-peer network. Current peer-to-peer messaging protocols lack functionality that users expect from a messaging service, such as multi-device history and asynchronous messaging. These problems are currently being circumvented through centralized components. Current federated messaging protocols can provide most of the functionality that users demand from a messaging service but suffer from other problems. Federated protocols commonly have uncertainty in terms of interoperability in the network. Furthermore, federated messaging protocols require users to trust one node through which they send messages and assume that users have sufficient knowledge to make the correct decision of which node to trust. Users have been shown to become concentrated on one or a few nodes, which leads to many of the problems with a centralized messaging service. This study presents a decentralized messaging protocol that operates on so-called canister smart contracts on the Internet Computer blockchain. The Internet Computer operates on nodes provided by independent data centers with a consensus model that allow up to one-third of the data centers to be faulty or malicious. The presented messaging protocol allows for messages to be sent from one public key to a collection of public keys and stores the messages on the Internet Computer. New canister smart contracts are created once the previous ones are out of memory to provide theoretically infinite scalability. The evaluation of the presented messaging protocol shows that it takes approximately 5 seconds to send a message and less than 1 second to retrieve messages. Furthermore, the cost of sending and storing one million messages with a size of 100 kB for one year is estimated at $4,200. / Centraliserade meddelandetjänster kan förbättras gällande säkerhet och integritet med hjälp av end-to-end-kryptering. Det finns dock fortfarande problem med säkerhet, integritet, tillgänglighet och öppenhet i centraliserade meddelandetjänster. Dessa problem kan undvikas eller minskas genom att använda en decentraliserad arkitektur. De mest anmärkningsvärda tidigare försök på decentraliserade meddelandeprotokoll har baserats på peer-to-peer- eller federerade nätverk. De nuvarande peer-to-peer-protokollen för meddelandehantering saknar funktionalitet som användare förväntar sig av en meddelandetjänst, exempelvis historik på flera enheter och asynkrona meddelanden. Dessa problem kringgås för närvarande genom centraliserade komponenter. De nuvarande federerade meddelandeprotokollen kan tillhandahålla de flesta av de funktioner som användare förväntar sig av en meddelandetjänst, men lider av andra problem. Federerade protokoll är ofta osäkra när det gäller driftskompatibilitet i nätverket. Dessutom kräver federerade meddelandeprotokoll att användarna litar på en nod som de skickar meddelanden genom, och förutsätter att användarna har tillräckligt med kunskap för att fatta rätt beslut om vilken nod de ska lita på. Det har visat sig att användarna samlas på en eller ett fåtal noder, vilket leder till många av de problem som finns i en centraliserad meddelandetjänst. I den här studien presenteras ett decentraliserat meddelandeprotokoll som är uppbyggt av, så kallade, canister smart contracts på blockkedjan Internet Computer. Internet Computer fungerar på noder som tillhandahålls av oberoende datacenter med en konsensusmodell som tillåter att upp till en tredjedel av datacentren kan vara felaktiga eller illvilliga. Det presenterade meddelandeprotokollet gör det möjligt att skicka meddelanden från en offentlig nyckel till en samling offentliga nycklar och lagrar meddelandena på Internet Computer. Nya canister smart contracts skapas när de föregående har slut på minne för uppnå teoretiskt sett oändlig skalbarhet. Utvärderingen av det presenterade meddelandeprotokollet visar att det tar ungefär 5 sekunder att skicka ett meddelande och mindre än 1 sekund att hämta meddelanden. Dessutom uppskattas kostnaden för att skicka och lagra en miljon meddelanden med en storlek på 100 kB i ett år till 4200 dollar.

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.

In this dissertation, we address the problem of vagueness in traditional legal contracts by presenting novel methodologies that aid in the paradigm shift from traditional legal contracts to smart contracts. We discuss key enabling technologies that assist in converting the traditional natural language legal contract, which is full of vague words, phrases, and sentences to the blockchain-based precise smart contract, including metrics evaluation during our conversion experiment. To address the challenge of this contract-transformation process, we propose four novel proof-of-concept approaches that take vagueness and different possible interpretations into significant consideration, where we experiment with popular vendors' existing vague legal contracts. We show through experiments that our proposed methodologies are able to study the degree of vagueness in every interpretation and demonstrate which vendor's translated-smart contract can be more accurate, optimized, and have a lesser degree of vagueness. We also incorporated the method of fuzzy logic inside the blockchain-based smart contract, to successfully model the semantics of linguistic expressions. Our experiments and results show that the smart contract with the higher degrees of truth can be very complex technically but more accurate at the same time. By using fuzzy logic inside a smart contract, it becomes easier to solve the problem of contractual ambiguities as well as expedite the process of claiming compensation when implemented in a blockchain-based smart contract.