The Internet of Things (IoT) is a technology aimed at developing a global network of machines and devices that can interact and communicate with each other. Supporting IoT, therefore, requires revisiting the Internet’s best effort service model and reviewing its complex communication patterns. In this dissertation, we explore the unique characteristics of IoT traffic and examine IoT systems. Our work is motivated by the new capabilities offered by modern Software Defined Networks (SDN) and blockchain technology. We evaluate IoT Quality of Service (QoS) in traditional networking. We obtain mathematical expressions to calculate end-to-end delay, and dropping. Our results provide insight into the advantages of an intelligent edge serving as a detection mechanism. Subsequently, we propose SADIQ, SDN-based Application-aware Dynamic Internet of things QoS. SADIQ provides context-driven QoS for IoT applications by allowing applications to express their requirements using a high-level SQL-like policy language. Our results show that SADIQ improves the percentage of regions with an error in their reported temperature for the Weather Signal application up to 45 times; and it improves the percentage of incorrect parking statuses for regions with high occupancy for the Smart Parking application up to 30 times under the same network conditions and drop rates. Despite centralization and the control of data, IoT systems are not safe from cyber-crime, privacy issues, and security breaches. Therefore, we explore blockchain technology. In the context of IoT, Byzantine fault tolerance-based consensus protocols are used. However, the blockchain consensus layer contributes to the most remarkable performance overhead especially for IoT applications subject to maximum delay constraints. In order to capture the unique requirements of the IoT, consensus mechanisms and block formation need to be redesigned. To this end, we propose Synopsis, a novel hierarchical blockchain system. Synopsis introduces a wireless-optimized Byzantine chain replication protocol and a new probabilistic data structure. The results show that Synopsis successfully reduces the memory footprint from Megabytes to a few Kilobytes with an improvement of 1000 times. Synopsis also enables reductions in message complexity and commitment delay of 85% and 99.4%, respectively

The South African property process is cumbersome, tedious, and complex mainly since it is a manual paper-based system that involves numerous activities of many disparate firms and organisations in the private sector as well as business processes of regulatory agencies, public sectors departments and other institutions. Although much effort had been made by private organisations to automate pockets of the process, the integration efforts are still founded in paper documents. The purpose of this study was to investigate the conveyancing end-to-end process in South Africa in order to develop a conceptual framework that could be used to eliminate paper and dematerialise the land registration process. The study was guided by the following research question: How can the end-to-end property transfer process be integrated among the different role players to dematerialise property transfers? Seated in the interpretative paradigm, an exploratory study was undertaken. The study followed a multidisciplinary approach which incorporated aspects of records management, supply chain management, land administration management, information technology and payment systems. Nineteen in-depth, semi-structured qualitative interviews were conducted with major organisations and societies (i.e. stakeholders) involved in property exchanges in South Africa. These included the South African Reserve Bank, The South African Deeds Registry, National Treasury, The Law Society of South Africa, The Surveyor General and various vendors which operate within the property sphere. These interviews were analysed using content analysis, and documentary evidence were used to triangulate the data collected. The study revealed that private organisations and banks are more ready to embrace dematerialisation than governmental institutions. The main findings of the study were that a need existed for the integration of information and data from the onset of the property application, dematerialisation in addition to digitisation should be incorporated into e-DRS, there is a need for a centralised information sharing capability, same-day, irrevocable payments must be implemented and biometric information can be used to validate parties involved in each transaction. The findings were used to develop a framework for a dematerialised electronic deeds registration in South Africa, which were further generalised for use in other industries. It is recommended that key supply chain partners are integrated into a land administration system that is hosted by the deeds office. This study is of value to all organisations involved in the property land management administration processes, both in a private and governmental capacity, as well as indigenous tribunals. Recommendations for future studies were made. / Thesis (PhD)--University of Pretoria, 2017. / Information Science / PhD / Unrestricted

Distributed ledger technology (DLT) is one of the latest in a long list of digital technologies, which appear to be heading towards a new industrial revolution. DLT has become very popular with the publication of the Bitcoin Blockchain in 2008. However, when we consider its suitability for dynamic networking environments, such as the Internet of Things, issues like transaction fees, scalability, and offline accessibility have not been resolved. The IOTA Foundation has designed the IOTA protocol, which is the data and value transfer layer for the Machine Economy. IOTA protocol uses an alternative blockless Blockchain which claims to solve the previous problems: the Tangle. This thesis first inquires into the theoretical concepts of both technologies Tangleand Blockchain, to understand them and identify the reasons to be compatible or not with the Internet of Things networking environments. After the analysis, the thesis focuses on the proposed implementation as a solution to address the connectivity issue suffered by the IOTA network. The answer to the problem is the development of a Neighbor Discovery algorithm, which has been designed to fulfill the requirements demanded by the IOTA application. Dealing with IOTA network setup can be very interesting for the community that is looking for new improvements at each release. Testing the solution in a peer-to-peer specific protocol (PeerSim), with different networking scenarios, allowed us to get valuable and more realistic information. Thus, after analyzing the results, we were able to determine the appropriate IOTA network configuration to build a more reliable and long-lasting network.

Diese Arbeit untersucht, inwieweit durch den Einsatz der Distributed-Ledger-Technologie bzw. der Blockchain-Technologie im Grundbuchwesen Immobilientransaktionen hinsichtlich der Transaktions-kosten effizienter durchgeführt werden können. Dazu werden zunächst, basierend auf dem Require-ments Engineering, die Anforderungen des Grundbuchs an eine mögliche Trägertechnologie entwickelt und gezeigt, dass sich die Distributed-Ledger-Technologie als eine solche Trägertechnologie qualifi-ziert. Darauf aufbauend werden zwei fachliche Architekturentwürfe eines blockchain-basierten Grund-buchs zur Abwicklung von Immobilientransaktionen konzipiert und mit den gegenwärtigen Prozessen hinsichtlich der Transaktionskosten verglichen sowie evaluiert. Resümierend kommt diese Arbeit zu dem Schluss, dass eine Immobilientransaktion in Deutschland nicht gänzlich peer-to-peer zwischen Käufer und Verkäufer abgewickelt werden kann, da auch die Blockchain-Technologie das Grundprob-lem des Misstrauens nicht ohne einen Intermediär bzw. einen vertrauenswürdigen Garanten, der den berechtigten Bezug von virtuellem Token zu einem tatsächlich existenten Grundstück in der realen Welt sicherstellt, vollständig lösen kann. Gleichwohl kann durch die Kombination eines Blockchain-Grund-buchs mit Smart Contracts ein enormes Einsparpotenzial im Hinblick auf die Transaktionskosten bei Grundbuchtransaktionen erzielt werden.:1 Einleitung 1.1 Problem- und Zielstellung 1.2 Vorgehen und Methodik 2 Grundlagen 2.1 Transaktionskosten 2.1.1 Transaktionskosten und deren Relevanz für Volkswirtschaften 2.1.2 Transaktionskosten in der Immobilienwirtschaft 2.2 Das deutsche Grundbuch 2.2.1 Aufbau und Inhalte 2.2.2 Prinzipien 2.2.3 Grundbuchamtliches Eintragungsverfahren 2.2.4 Ergebniszusammenfassung 2.3 Immobilientransaktion 2.3.1 Rollen und Beziehungen der Akteure 2.3.2 Transaktionsablauf 2.3.3 Transaktionskosten 2.3.4 Ergebniszusammenfassung 2.4 Distributed-Ledger-Technologie 2.4.1 Distributed Ledger 2.4.2 Blockchain 2.4.3 Blockchain-Typisierung 2.4.4 Ergebniszusammenfassung 3 Literaturübersicht zur DLT im Kontext des Grundbuchwesens 3.1 Definition des Untersuchungsumfangs 3.2 Konzeptualisierung der Thematik 3.3 Literaturrecherche 3.4 Literaturanalyse 3.5 Internationale Pilotprojekte 3.5.1 Schweden 3.5.2 Cook County 3.5.3 Estland 3.5.4 Georgien 4 Requirements Engineering 4.1 Vorgehen 4.2 Identifizierung, Formulierung und Analyse der Anforderungen 4.3 Gegenüberstellung von Anforderungen und Eigenschaften der DLT 5 Blockchain-basierte Architekturentwürfe für Grundbuchwesen und Immobilientransaktionen 5.1 Konzeption fachlicher Architekturentwürfe 5.2 Blockchain-basiertes grundbuchamtliches Eintragungsverfahren 5.3 Architekturentwurf Ökosystem 5.3.1 Rollen und Beziehungen 5.3.2 Transaktionsablauf 5.4 Machbarkeit und Implikationen auf die Transaktionskosten 5.4.1 Architekturentwurf Infrastruktur 5.4.2 Architekturentwurf Ökosystem 5.5 Ergebniszusammenfassung 6 Zusammenfassung und Ausblick 6.1 Zusammenfassung der Ergebnisse 6.2 Limitationen 6.3 Ausblick

Fueled by the success of cryptocurrencies such as Bitcoin, blockchain technology has emerged as an interesting and promising technological solution in a variety of industries. However, it remains unclear to what extent blockchain technology possesses the potential to transform existing business models or to enable new business models. So far, scientific studies have been predominantly technologically driven; the economic viability, e.g., in the form of innovative, sustainable business models, as well as the acceptance of blockchain technology have not been sufficiently investigated. This dissertation addresses this research gap and focuses on three domains: The financial sector, the temporary employment industry, and the healthcare sector. To investigate the impact of blockchain technology on business model innovation as well as its impact on existing business models, quantitative and qualitative methods are applied in the form of a mixed-method approach. Within this approach, (acceptance) models, tools, methods, and prototypes are developed. Moreover, recommendations for decision makers are elaborated and central economic, ecological, political, legal, social, and ethical challenges and opportunities of blockchain technology for business models and business model innovations are identified and discussed. The results of this dissertation support economic and political decision makers as well as researchers in the fields of blockchain technology and business model innovation.

Today there exist no standardized payment solution for performing micropayments between Internet of Things (IoT) devices. This study was conducted to examine whether Distributed Ledger Technology (DLT) could be suitable as a micropayment solution for IoT. Also, a more general demand for a scalable micropayment solution was examined, along with its potential. A qualitative study was performed by first conducting eight unstructured interviews regarding the subjects DLT and IoT, to be used as a complement to the literature research. Then, one unstructured and five semi-structured interviews were held to answer the research questions. The Bitcoin blockchain does not work as a micropayment solution, due to scalability issues. This study identified a positive outlook on the idea of Lightning Network, solving the scalability problems with off-chain transactions. However, since a fully functioning network is yet to be implemented, there exist uncertainties, for example regarding how decentralized it will really become. Also, issues considering the usage of DLT:s on small IoT devices arose, stemming from CPU and storage constraints. A demand of a sustainable micropayment solution was identified, possibly being a catalyst of the emergence of pay-per-use business models. Considering more powerful IoT devices, the Lightning Network could function as a micropayment solution. Such a technology is sought after, and its applicability will only increase as IoT devices evolve. / Det finns idag ingen standardiserad betalningslösning för att genomföra mikrobetalningar mellan Internet of Things (IoT) enheter. Denna studie genomfördes för att undersöka huruvida Distributed Ledger Technology (DLT) skulle kunna användas som en mikrobetalningslösning för IoT. En mer generell eterfrågan för en skalbar mikrobetalningslösning, och effekterna av en sådan, undersöktes. En kvalitativ studie genofördes, där åtta ostrukturerade intervjuer gällande ämnena DLT och IoT, hölls för att komplementera litteraturstudierna. Sedan genomfördes en ostrukturerad och fem semi-strukturerade intervjuer för att kunna besvara de frågeställningar som definierats. Bitcoin blockkedjan funderar inte som en mikrobetalningslösning på grund utav dess skalbarhetsproblem. Studien identifierar en positiv syn på Lightning Network, som löserskalbarhetsproblemen genom att använda sig av transaktioner utanför kedjan. Denna lösning är dock inte fullständigt implementerad, vilket leder till flera osäkerheter angående exempelvis hur decentraliserat nätverket verkligen kommer att bli. Utöver detta finns även svårigheter med användandet av DLT:s för små IoT-enheter, vilket härstämmar ifrån deras CPU- och lagringsbegränsningar. En efterfrågan på en hållbar mikrobetalningslösning identifieras, och denna skulle kunna fungera som en katalysator för etablerandet av pay-per-use affärsmodeller. Tittar vi på mer kraftfulla IoT-enheter skulle Lightning Network fungera som en mikrobetalningslösning. En sådan teknologi är eftertraktad och dess användbarhet kommer bara att växa i och med utvecklingen av IoT-enheter.

Shareholder Registers provide vital information about ownership structures in corporations and are of interest for a diverse set of stakeholders such as the Swedish Companies Registration Office (and its international equivalences), stockholders, the SEC to name a few. Eventhough the information is public and the interest is high, transparency is limited. Blockchain technology offers a unique set of benefits that can help enhance transparency and security in shareholder registers. Therefore, this thesis aims to investigate how shareholder registers can benefit from blockchain technology by implementing a proof-of-concept and conducting a market analysis. The proof of concept consists of a small-scale implementation of a blockchain network with essential functionality meant to simulate a shareholder register. The market analysis was conducted through interviews with executives from several companies. There is good reason to believe blockchain technology has a future in shareholder registers. The decentralied nature of blockchain implies that it can be leveraged to provide security and transparency benefits that contemporary alternatives cannot. The Proof of concept proves that it can be done conceptually and the market analysis shows that there is demand for it that has not been filled by other alternatives. / Aktieböcker lagrar viktig information som berör aktiebolags ägarstrukturer och är av intresse för flertalet intressenter som Bolagsverket, aktieägare och Finansinspektionen för att nämna ett fåtal. Trots att aktieboken är en allmän handling och att intresset för den är så stort präglas aktieböcker av låg transparens. Blockkedjeteknik erbjuder en uppsättning unika egenskaper som kan bidra med ökad transparens och säkerhet för aktieägare. Detta kandidatarbete ämnar därför att undersöka hur blockkedjeteknik kan bidra till att göra aktieböcker bättre i detta avseende genom att genomföra ett koncepttest samt en marknadsanalys. Koncepttestet består av en småskalig implementation av ett blockkedjenätverk med grundläggande funktionalitet menat att simulera en aktiebok. Marknadsanalysen består av intervjuer genomförda med chefer från flera olika aktiebolag. Det finns goda skäl att tro på att blockkedjeteknik har en framtid inom aktieböcker. Blockkedjeteknikens decentraliserade natur medför möjligheter att förbättra säkerhet och transparens hos dagens aktieböcker. Arbetets koncepttest visar att det kan göras rent konceptuellt medan marknadsanalysen visar att det finns en efterfrågan som inte fyllts av andra alternativ.

Blockchains and Byzantine Fault Tolerance form the basis of decentralized currencies and ledgers, such as Bitcoin, Ripple, ZeroCash, and Ethereum. Several studies have focused on the currency aspects (e.g. authenticity, integrity, anonymity, and independence from central banks). In this thesis, we start by exploring to understand the security challenges and practical solutions for building simple payment networks. Then, we leverage such understanding in identifying the security challenges of more advanced and complex systems, in particular Futures Exchanges. The decentralization of a Futures Exchange poses new security challenges: i) the interplay between the security and economic viability, i.e. using the Price Discrimination Attack one can strategically force a trader out of the market when the trader's anonymity is broken; ii) the non-monotonic security behavior of an Exchange, i.e. an honest action may invalidate security evidence; and iii) the proportional burden requirement in the presence of high-frequency participants. Our goal is to enucleate the non-trivial design principles to resolve these challenges for building secure and distributed financial exchanges. We demonstrate the application of the distilled design principles by building a cryptographic reference for a futures exchange called FuturesMEX. We also simulate the performance of a FuturesMEX Proof-of-Concept with the Lean Hog market data obtained from the Thomson Reuters Ticks History DB. The results show that the obtained protocol is feasible for a low-frequency market such as Lean Hog. Furthermore, we investigate an extension of public markets, i.e. dark pools (private markets), in which the order book information is conditionally visible to some (financially) suitable parties. We propose a new cryptographic scheme called Witness Key Agreement that makes dark trading possible by probing prices and volumes based on committed financial information Finally, we evaluate the theoretical and practical performance of the new scheme; using a simulation of the dark pool data collected from the aggressive Bloomberg Tradebook, we obtain positive results.

Yes / • This article discusses the current situation in the market of cryptocurrencies and joins the debate about the regulation of these financial innovations. • It argues that the appearance of cryptocurrencies was a response to market demand for more affordable and more inclusive banking. • It also argues that distributed ledger technology (DLT) which supports cryptocurrencies and has different characteristics than the technology used by traditional banking could help to create with cryptocurrencies a new, lower cost, more inclusive financial ecosystem separate from the traditional one. • The two ecosystems (traditional and new one) would form a larger two-tier financial ecosystem, which, overall would be more inclusive and more affordable. Also, it would be more effective in containing contagion and major economic disruption during future financial crises. • The current reliance on a single, ever growing, and immensely complex financial ecosystem is not sustainable longer term as systemic risks grow with the system and there are no mechanisms available to fully eliminate these risks. The costs of regulating the current market architecture are also excessively high.

The changing nature of the energy grid in recent years has prompted key stakeholders to think of ways to address incoming challenges. Transactive energy is an approach that promises to dynamically align active grid elements coming up in the previously inactive consumers' side to achieve a reliable and smarter grid. This work models the distribution grid structure as a combination of microgrids. A blockchain-in-the loop simulation framework is modelled and simulated for a residential microgrid using power system simulators and transactive agents. Blockchain smart contracts are used to coordinate peer-to-peer energy transactions in the microgrid. The model is used to test three market coordination schemes: a simple auction-less scheme, an auction-less scheme with a normalized sorting metric and an hour ahead single auction scheme with penalties for unfulfilled bids. Case studies are presented of a microgrid with 30 homes, at different levels of solar and energy storage penetration within the microgrid, all equipped with responsive and unresponsive appliances and transactive agents for the HVAC systems. The auction-less scheme with a normalized sorting metric is observed to provide a fairer advantage to smaller solar installations in comparison to the simple auction-less method. It is then concluded that the auction-less schemes are most beneficial to users, as they would not need sophisticated forecasting technology to reduce penalties from bid quantity inaccuracies, as long as the energy mix within the microgrid is diverse enough. / Master of Science / The legacy energy industry involved the bulk transfer of energy from huge generation plants through long transmission lines to the end consumers. However, with the onset of improved renewable energy and information technologies, energy is now being generated closer to the consumer side with appliances capable of actively participating in the energy system now widely available. Transactive energy with blockchain has been proposed in order to dynamically coordinate these systems to work towards a more reliable and smarter grid using economic value in a transparent and secure way. This work models a transactive power grid as a combination of microgrids using a blockchain network to coordinate hourly peer-to-peer energy transactions. The blockchain-in-the-loop simulation model is used to compare three different market mechanisms in a residential microgrid of 30 homes with varying levels of solar panels, batteries and transactive thermostats installed. Two auction-less schemes - one with a normalized sorting metric - and an hour ahead single auction mechanism are analyzed. While the auction-less scheme with the normalized metric is seen to be fairer than the simple auction-less scheme, it is concluded that the auction-less schemes are most beneficial to residents. This is because sophisticated forecasting technology would not be needed like in the hour ahead auction scheme, provided that the microgrid has participants with diverse energy consumption and production profiles throughout the day.