There have been many approaches where Blockchain was used to implement an E- voting scenario. Some used smart contracts, some used different Consensus algorithms like Proof of work, proof of stake, etc. Every implementation had some problems and some of them are the throughput of transactions, the feasibility, the cost of transactions, consensus mechanisms and so on. Consensus mechanisms play an important role in performance of a blockchain system and thus we outline the use of Proof of Authority -Authority Round implementation for a private blockchain based E-voting system and try to figure out what the system can yield in terms of performance.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Drug counterfeiting or adulteration is a worldwide concern due to the serious consequences they generate, especially in the health and economic sectors. This concern is greater in Peru, as it is among the top five countries with drug counterfeiting incidents in the Americas, according to a study carried out in 2018 by the Pan American Health Organization. In this paper, we present our project, which aims at implementing a technological solution that provides reliable information on the origin and authenticity of these products in Peru to the drug consumer user, preserving the security and integrity of the exposed information using Blockchain technology. Likewise, it allows showing detailed drug characteristics, such as: composition, pharmaceutical form, active ingredients, among other relevant information. The technological solution, proposed by our project, aims at publishing the commercial origin of drugs from their sale in laboratories and distributors to the sale to the public in pharmacies. In the development of this paper, a bibliographic review of research on the use of blockchain technology is presented, as well as its benefits in the health sector, the architecture used by the system and the conceptual commercialization chain that supports it, and the qualitative and quantitative validation for the drug query service is shown. / Revisión por pares

區塊鏈是一種基於點對點網路架構的分散式網路技術,近年來已經有 許多快速蓬勃的發展。區塊鏈從一開始在比特幣上的數位貨幣應用到以太 坊上能夠運行準圖靈完備 (Turing complete) 的智能合約,已經多了許多不 同面貌與應用。 區塊鏈運作的主要核心技術在於共識機制,即如何讓所有網路上的節 點對所發生的交易都有同樣的共識。比特幣與以太坊這兩個最著名的區塊 鏈的共識機制皆是工作量證明 (Proof of Work)。工作量證明機制在公開鏈 上非常適合,但是對於非公開鏈就會變成負擔。本篇論文針對以太坊,實 作出一個具有模組性的共識機制,讓以太坊除了工作量證明,也能夠實現 拜占庭容錯 (Byzantine Fault Tolerance) 的共識演算法,並且保留以太坊智 能合約功能,以利的以以太坊發展聯盟區塊鏈平台。 / Blockchain is a kind of distributed ledger technology, which is based on P2P network protocol and a distributed consensus mechanism. It has developed rapidly in recent years. There are many kinds of blockchains, such as the most noted ones, Bitcoin and Ethereum, the latter of which contains a Turing complete language for developing programs running on top of it. A core technical component of a blockchain is its consensus mechanism, which implements the method of reaching consensus about what transactions have been done among all peer nodes in the network. The consensus mechanism of Bitcoin and Etheruem are Proof of Work (PoW), which is often referred to as mining. Although Proof of Work is suitable for public blockchains, it may become a burden for private or consortium blockchains. The objective of this thesis is to extend the consensus module of Ethereum with Byzantine Fault Tolerance (BFT) consensus algorithm, which can speed up the consensus process significantly when the number of network peers is not large. This can be a key step for making Ethereum suitable for suporting consortium blockchains.

Memoria para optar al título de Ingeniero Civil Eléctrico / El desarrollo de nuevas tecnologías en el sector energético como medidores inteligentes, generación distribuida, electromovilidad y el Internet de las cosas prometen traer beneficios tanto a a la sociedad como al sector privado. Sin embargo, esto también supone grandes y nuevos desafíos para la comunidad, ya sea en la búsqueda de soluciones que implementen estas tecnologías de manera eficiente o en la búsqueda de tecnologías unificadoras. En línea con esto último, el uso de la tecnología blockchain promete revolucionar el sector energético, integrando elementos como la digitalización, descentralización y la eliminación de intermediarios. El presente trabajo desarrolla una aplicación blockchain para el sector energético chileno. Para esto se realiza una investigación de las aplicaciones de blockchain para el sector energía existentes a nivel global y local, así como un estudio del panorama energético chileno en torno a esta tecnología. De esta contextualización se corrobora que existen aplicaciones de blockchain para el sector energético tales como transferencia de energía Peer to Peer (P2P), aplicaciones para vehículos eléctricos y certificación de datos, siendo la primera la aplicación que explota de mejor manera las cualidades de la tecnología blockchain. La aplicación desarrollada consiste en un sistema de economía colaborativa para agentes bajo un modelo organizacional de cooperativa, en pos de la realización de proyectos de generación distribuida. El desarrollo de esta plataforma se realiza utilizando la plataforma Ethereum y los resultados son obtenidos desplegando la aplicación en la testnet de Rinkeby, simulando el comportamiento de los agentes de forma aleatoria. Los resultados obtenidos prueban la viabilidad técnica de la aplicación y la estimación de un costo operacional de la aplicación inferior a 500 CLP por proyecto, con 100 agentes usando la plataforma. La importancia de este trabajo consiste en mantener actualizado el sector energético chileno al explorar el desarrollo una tecnología nueva que promete ser revolucionaria. En el caso de blockchain, su potencial va en línea con el avance del sector energético nacional hacia la descentralización, digitalización y la generación distribuida en pos un futuro energético más sustentable. Se espera que en el futuro la existencia de aplicaciones blockchain en energía aumente a medida que proliferen otras tecnologías relativamente nuevas como las smart grids, la electromovilidad y el Internet de las cosas en Chile.

Cryptocurrencies have developed and widely spread within recent years. Their anonymous and decentralised characteristics have attracted criminals who leverage these technologies to sell and purchase illicit goods on the black market while concealing their identities and avoid prosecution. The new development of cryptocurrencies and their underlying architecture blockchain has had positive and negative effects on the success of law enforcement investigations. It is perceived as a threat when there are factors that increase the complexity of law enforcement investigations due to the use of highly anonymous cryptocurrencies and Bitcoin mixers. Cryptocurrencies are also perceived as a threat when criminals use them for money laundering purposes. Conversely, the rise of cryptocurrencies also introduces new opportunities for law enforcement investigations. Records of cryptocurrency transactions in the blockchain help law enforcement to trace suspicious addresses by the emergence and improvement of analysis tools. In parallel, anti- money laundering (AML) regulations and the financial authorities have proved to play a key role in fighting against money laundering and gather information on suspicious activities carried out through financial institutions. The analysis of this dissertation sets forth that...

Indiana University-Purdue University Indianapolis (IUPUI) / Current supply chain information systems are transaction-based and suffer from lack of real-time transparency. Furthermore, they are often centralized and therefore cannot adequately scale to include a large number of small and medium size companies. This thesis presents a hybrid peer-to-peer supply chain physical distribution framework (HP3D) that addresses these increasingly critical gaps in a global market. HP3D leverages the advantages of hybrid networks through flexible peers and a light-weight index server in order to share supply chain physical distribution information in pseudo real-time among stakeholders. The architecture of HP3D consists of a hierarchy of dynamic sub-networks that evolve based on market demands and digitize the transfer of goods between suppliers and customers. These sub-networks are created on demand, emulate the end-to-end movement of the shipment and terminate when the delivery of goods is completed. A variation of blockchain technology is also proposed in order to increase the security level of the proposed framework.

Non-Fungible-Token (NFTs) sind eine Blockchain-Anwendung, die es erlaubt, die Echtheit und Eigentumsrechte von physischen und digitalen Gütern nachzuweisen. Mit Hilfe dieser Technologie entwickeln sich in zahlreichen Branchen neue Geschäftsfelder und Nutzungsmöglichkeiten, weshalb sich die vorliegende Masterarbeit mit dem Thema Blockchain- und NFT-Technologie in der Buchbranche auseinandersetzt. Das Ziel der Arbeit ist die Untersuchung der Möglichkeiten und Grenzen der Technologie für Verlage und Autoren. Dabei wird erforscht, welche Voraussetzungen auf Seiten der Buchbranche und der Endkunden für einen erfolgreichen Einsatz von NFTs nötig sind. Dazu werden die theoretischen Grundlagen von Blockchains, mit Fokus auf die Ethereum-Blockchain, und NFTs behandelt. Zur Analyse des aktuellen Standes werden bisherige Anwendungsgebiete anhand von Case Studies buchferner Branchen und der aktuelle Digitalisierungsstand der Buchbranche vorgestellt. Zur Erreichung der Zielsetzung finden im Rahmen der empirischen Untersuchung eine qualitative und quantitative Befragung von Experten und Endkunden statt. Die Untersuchungen haben ergeben, dass es zahlreiche Möglichkeiten gibt, NFTs als Autor oder Verlag einzusetzen, damit jedoch sowohl technische Grenzen als auch hohe Kosten verbunden sind. Für eine erfolgreiche Umsetzung müssen viele Faktoren und Voraussetzungen berücksichtigt werden. Zusätzlich ist das Wissen und die Bereitschaft gegenüber der Technologie auf Seiten der Endkunden sehr beschränkt, was die Zielgruppenansprache für Autoren und Verlage mit enormer Aufklärungsarbeit verbindet. Aufgrund dieser Ergebnisse sollten Akteure der Buchbranche sich bereits jetzt mit der Technologie auseinandersetzen, sich Wissen aneignen und die Bedürfnisse der Zielgruppe analysieren, um in Zukunft bei Eignung eines Buchprojektes und Erfüllung aller nötigen Voraussetzungen in den NFT-Markt einsteigen zu können.:Abbildungsverzeichnis Abkürzungsverzeichnis 1. Einleitung 1.1 Relevanz der Thematik 1.2 Zielsetzung und Vorgehensweise 2. Grundlagen von Blockchain und NFTs 2.1 Blockchain 2.1.1 Definition und Funktionsweise 2.1.2 Eigenschaften 2.1.3 Ethereum-Blockchain 2.1.4 Konsensmodell Proof of Work 2.1.5 Konsensmodell Proof of Stake 2.1.6 Smart Contracts als Softwareanwendung der Blockchain 2.2 NFTs 2.3 Metaverse 3. Bisherige Anwendungsgebiete von NFTs 3.1 Vorbemerkungen zur Untersuchung 3.2 Untersuchungsobjekte 3.2.1 Gaming 3.2.2 Kunst 3.2.3 Musik 3.3 Ergebnis 4. Aktueller Stand der Digitalisierung in der Buchbranche 5. Empirische Untersuchung 5.1 Vorbetrachtung 5.2 Wahl der Stichprobe 5.2.1 Experten 5.2.2 Endkunden 5.3 Aufbau der Untersuchungselemente 5.3.1 Experteninterviews 5.3.2 Endkundenbefragung 5.4 Planung der Untersuchung 5.4.1 Experteninterviews 5.4.2 Endkundenbefragung 5.5 Planung der Auswertung 5.5.1 Experteninterviews 5.5.2 Endkundenbefragung 6. Darstellung der Ergebnisse 6.1 Ablauf der Untersuchung 6.1.1 Experteninterviews 6.1.2 Endkundenbefragung 6.2 Auswertung der Forschungsinstrumente 6.2.1 Experteninterviews 6.2.2 Endkundenbefragung 7. Ergebnisbildung 7.1 Beantwortung der forschungsleitenden Fragen 7.2 Handlungsempfehlungen 8. Fazit Bibliografie Selbstständigkeitserklärung Anhang

L’augmentation constante de la consommation de vidéos par des services par contournement(Over-The-Top) met à mal l’architecture actuelle d’Internet. Alors qu’une écrasante majorité de labande passante aujourd’hui est allouée à la livraison de contenus, les acteurs de l’Internet, tels queles fournisseurs de contenus, les réseaux de distribution de contenus et les fournisseurs d’accès sontobligés d’optimiser leurs réseaux pour supporter la qualité d’expérience attendue par l’utilisateurfinal. Ces réseaux couteux et spécialisés participent à l’ossification de l’Internet, rendant l’évolutionde son architecture plus difficile à moyen terme. En effet, un choix trop spécifique de dimensionnementdes liens et de la localisation des middle-boxes peut être un frein à une mise à jour ultérieureen vue du support de nouveaux cas d’utilisation. Heureusement, les technologies de virtualisationrécemment promues par les grands opérateurs Internet, les vendeurs de solutions et les organismesde standardisation, permettent une réelle programmabilité du réseau et une plus grande versatilitédans les usages de nouveaux équipements. En effet, l’agilité apportée par ces technologies permet ledéploiement de Fonctions Réseaux Virtuelles (VNF, Virtual Network Functions) pouvant s’exécutersur des serveurs de série à bas coût. Quant au Software-Defined Networking , il rend possible unegestion du réseau logiquement centralisée permettant la programmation des commutateurs.L’objectif de cette thèse est de montrer comment la distribution de contenu peut être amélioréecollaborativement à l’aide de la programmabilité de réseaux. Tout d’abord, nous proposons CDNaaS,une solution complète de réseau de livraison de contenu déployée sur une plateforme de "fonctionsréseaux en tant que service" adoptée et évaluée à large échelle dans le cadre du projet Européen FP7T-NOVA. Nous précisons les interfaces, l’architecture et les choix de conception fait pour développerla plateforme afin de fournir performance, auto-dimensionnement et réutilisabilité. Puis, nous proposonsdeux modèles de collaboration permettant aux acteurs de la livraison de contenu de travaillerensemble afin d’augmenter la qualité d’expérience pour l’utilisateur final, tout en promouvant unecompétition saine et une répartition équilibrée de la valeur ajoutée. Finalement, nous étudions lesdéfis liés à l’allocation de ressources virtuelles dans le cas d’un service vCDN, et proposons plusieursheuristiques et algorithmes permettant l’optimisation du coût du service.Cette thèse ouvre la voie à une distribution de contenu collaborative permettant aux utilisateursd’accéder à leurs contenus avec un haut standard de qualité, tout en contribuant à un développementsain de l’Internet. / The constant rise of Over-The-Top video consumption nowadays challenges the current Internetarchitecture. As an overwhelming majority of the bandwidth today is dedicated to the deliveryof video contents, Internet actors such as Content Providers, Content Delivery Network, InternetService Providers are forced to optimize their networks to support the Quality of Experience expectedby the End-Users . Such costly specialized networks participate to the so-called "ossification" of theInternet whichmakes the architecture harder to update, as the placement and dimensioning of linksand middleboxes may be hard to change in the future to support new use cases. Fortunately, thetrend of Virtualizating and Softwarizing the networks pushed by major Telco operators, vendors andstandardization bodies has given hopes that the computing and networking infrastructure can beeasily re-purposed. The agility promoted by technologies such as Network Function Virtualizationand Software Defined Networking makes it possible for middleboxes to be deployed as VirtualNetwork Functions that can run on "commercial off-the-shelf" hardware while having the networkmanaged by a logically centralized controller deploying network configurations on programmableforwarding devices.The goal of this thesis is to show how content distribution can be collaboratively improved thanksto Network Softwarization. First, we propose CDN-as-a-Service (CDNaaS), a complete solution tovirtualize a Content Delivery Network on top of a VNF-as-a-Service platform, adopted and evaluatedat large scale in the FP7 T-Nova European project. We elaborate on the interfaces, architecture anddesign choices made to implement the platform to support performance, automatic scaling andre-usability. Then, we propose two collaboration models allowing the content delivery actors to workjointly on improving End-User Quality of experience while fostering a healthy competition and a fairbalance of revenue. Finally, we study the challenges of NFV resource allocation for the vCDN serviceand propose several heuristics and algorithms to optimize the proposed solution in a cost-effectiveway. This thesis paves the way towards a collaborative content distribution allowing End-Users toaccess their content with the highest standards while contributing to a sound development of theInternet.

The financial services sector is riddled with efficiency challenges and high costs resulting from the use of legacy financial systems. A solution for these challenges exists in the form of blockchain technology. However, adoption of blockchain in the financial services sector remains a challenge for several reasons. Key to this is the fact that the technology is still new, and there is a lack of clear information on how management of financial institutions can configure their organisations to prepare them for the adoption of the new technology. By investigating the technological aspects of blockchain technology; the organisational preparedness for adoption; and the environmental dynamics of financial services; this paper presents a framework for organisational adoption of blockchain technology. This framework will assist organisations to first reconfigure themselves to prepare for technological adoption; and second, align themselves to the requirements of adoption of blockchain technology. Through in-depth, semi-structured interviews with experts in the global financial services sector, it was found that there is a methodological approach to the adoption of blockchain technology. Blockchain advocates within organisations will be able to conduct an internal introspection into efficiency challenges they face, learn about blockchain technology, build a business case for adoption, reconfigure the organisation, align the organisation, and adopt blockchain to accord the organisation the necessary efficiencies. / Mini Dissertation (MBA)--University of Pretoria, 2021. / Gordon Institute of Business Science (GIBS) / MBA / Unrestricted

Blockchain was first described in 1991 by Stuart Haber and Scott Stornetta as a methodology to timestamp documents and became popular with the introduction of cryptocurrency in 2008. A blockchain can be both public and private and is often described as a special ledger (like a spreadsheet) with five distinctive features. (1) It is distributed, with no central database that if a copy is corrupted others can replace it. Although each participating member on the blockchain has access to the database, there is no single controller of the information. Every member can verify transactions directly without involving intermediaries. (2) Transactions are peer to peer. There is no central node for transactions. Each peer stores and forwards transactions to all other peers. (3) It is transparent, with all transactions visible in the blockchain. Members are given access to the blockchain and all nodes of the transaction. (4) It is immutable. Once a transaction is created in the chain and the accounts are updated, it cannot be altered. (5) It is based in cryptography, the connection of the blocks is cryptographically secured, and the last line of the block is added as the first line in the next block. Each block is connected to the preceding chain making the record chronological and permanent. Furthermore, the blockchain can be programmed to include rules that activate transactions between nodes. Blockchain technology expedites and solves many business challenges. For example, blockchain technology can be used for payment processing, fraud detection, supply chain management, and verification of ownership. Blockchain technology continues to gain recognition by consumers and companies promising to disrupt existing centralized establishments while improving transparency and increasing accountability. This special session has several objectives. First, we will discuss blockchain technology and how it functions. Second, we will introduce cases of how industries are using this technology. Finally, we will propose a research framework that corresponds with four distinct exchange relationships: consumer-to-consumer, firm-to-firm, firm-to-consumer, and consumer-to-firm.