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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Blockchain and prediction markets : An analysis of three organizations implementing prediction markets using blockchain technology, and the future of blockchain prediction market

Fröberg, Emil, Ingre, Gustav, Knudsen, Simon January 2018 (has links)
Since the rise of Bitcoin in 2008, many have speculated about the scope of blockchain technology applications. Prediction markets, i.e. markets in which uncertain outcomes of future events are tradeable, is such an application; blockchain technology may offer several technological attributes that may facilitate prediction market implementations. This study describes and compares the platforms of three organizations that build blockchain prediction market platforms: Augur, Gnosis and Stox. By this, we provide a pertinent overview of current blockchain prediction market applications. Additionally, we conduct interviews with three Swedish blockchain experts clarifying blockchain technology strengths and weaknesses in relation to prediction markets. We identify five factors that are essential for prediction markets to aggregate and reflect information accurately: many actors participating, no actors being prevented from participating, a trustworthy setting function, freedom to create new contracts, and transparency. We conclude that blockchain technology has attributes that facilitate future prediction market implementations in accordance with these requirements. However, blockchain scalability issues pose a key challenge. / Sedan Bitcoins introduktion 2008 har många spekulerat kring omfattningen av blockkedjeteknologins tillämpningsområden. Prediktionsmarknader (eng. prediction markets), d.v.s. marknader i vilka det går att spekulera i osäkra resultat av framtida händelser, är ett sådant tillämpningsområde; blockkedjeteknologi kan tillhandahålla aspekter som främjar implementationer av prediktionsmarknader. Denna artikel beskriver och jämför plattformarna som tillhandahålls av tre organisationer som använder sig av blockkedjeteknologi for att bygga prediktions­marknadsplattformar: Augur, Gnosis och Stox. Genom detta tillhandahåller vi en helhetssyn över nuvarande prediktionsmarknadsplattformar som bygger på blockkedjeteknologi. Dessutom genomför vi intervjuer med tre svenska blockkedjeteknologiexperter, detta för att klargöra blockkedjeteknologis styrkor och svagheter i förhållande till prediktionsmarknader. Vi identifierar fem faktorer som är essentiella för prediktionsmarknaders förmåga att framgångsrikt aggregera och reflektera information: att många aktorer deltar, att inga aktorer är förhindrade från att delta, en tillförlitlig funktion för avgörande av utfall, frihet att skapa nya kontrakt, samt transparens. Vi drar slutsatsen att blockkedjeteknologi, med avseende på dessa faktorer, har egenskaper som förenklar implementationen av prediktionsmarknader. Å andra sidan utgör blockkedjors skalbarhetsproblem en signifikant utmaning.
142

A Buyer-Seller Protocol with Watermarking for Cloud Streaming : Towards an Ecosystem for Media Streaming / Ett köpar-säljareprotokoll med vattenmärkning för molnströmning : Mot ett ekosystem för media streaming

Björklund, Johan January 2017 (has links)
This work shares purpose with new directions in the philosophy of intellectual property, where self-expression and participation in the creation of culture are seen as key ingredients of human wellbeingand autonomy. A technical solution is explored that enables major labels and independent creatorsto publish music with equal reach to audiences, without the need for trusted third parties.The principal contribution is a buyer-seller protocol in the setting of untrusted service providersand a blockchain ledger. In the envisioned scenario, files are streamed from untrusted providers toend users. Encryption and watermarking, rather than obfuscation, are used to protect against anddisincentivize piracy. Watermarking bit rate, storage and communication overheads, and encryptionperformance are key parameters. Subscription and ad-supported pricing models are discussed. / Detta arbete delar syfte med nya idéer inom immaterialrättsfilosofi, där yttrande och delaktighet iskapandet av kultur ses som nödvändiga ingredienser för mänskligt välbefinnande och självständighet.Rapporten utforskar en teknisk lösning som möjliggör för stora mediebolag och oberoende artister attpublicera musik med samma åtkomst till publik, utan behov av betrodda tredjeparter.Det huvudsakliga bidraget är ett köpar-säljar-protokoll för en miljö med obetrodda service providersoch en blockchain ledger. I det föreställda sceneriot skickas filer från obetrodda parter till slutan-vändare. Kryptering och vattenmärkning, snarare än obfuskering, används för att skydda mot ochavskräcka från piratkopiering. Vattenmärkningens bithastighet, lagrings- och kommunikations-behov,samt krypteringens prestanda är avgörande parametrar. Subscription och ad-supported som prismod-eller diskuteras.
143

Blockchain database; technical background and a reconnaissance on an implementation within the banking industry / Blockchain-databas; teknisk bakgrund och en översikt över genomförandet inom banksektorn

Johansson, Tom, Charpentier, Viktor January 2017 (has links)
All human interaction can be depicted as exchanges. We exchange trivial information, feelings, assets and more. Valuable exchanges have one thing in common; they all require some degree of trust. In today’s society we rely on institutionalized trust when commencing an exchange of value. Typically, this role is filled by a vast ecosystem consisting of commercial banks, clearinghouses and other third parties. The recent rise of Bitcoin, Ethereum and consequent attention on the underlying technology, blockchain, questions the future of current ecosystem. This report aims at uncovering what blockchain is, what different implementations are currently available and how it would affect today’s ecosystem. It does so through semistructured interviews with actors within the current ecosystem as well as weighing in the views of blockchain evangelists. It highlights five key aspects that are crucial when implementing blockchain technology within the existing banking paradigm. Today’s organized societies require law and order which, to a large extent, is limited within the realm of public blockchain technology. With the insight of society’s infrastructural limitations, this paper argue that the current transaction system of our society favors a permissioned implementation with trusted nodes. Such a system would result in more efficient financial markets and lower costs of transacting. However, this paper acknowledge the virtues and reasons behind the rise of public blockchains. Given recent developments within the field and interesting concepts, the report does not dare to exclude a future of banking relying on public blockchain technology as the underlying database.
144

Blockchain Use for Data Provenance in Scientific Workflow

Sigurjonsson, Sindri Már Kaldal January 2018 (has links)
In Scientific workflows, data provenance plays a big part. Through data provenance, the execution of the workflow is documented and information about the data pieces involved are stored. This can be used to reproduce scientific experiments or to proof how the results from the workflow came to be. It is therefore vital that the provenance data that is stored in the provenance database is always synchronized with its corresponding workflow, to verify that the provenance database has not been tampered with. The blockchain technology has been gaining a lot of attention in recent years since Satoshi Nakamoto released his Bitcoin paper in 2009. The blockchain technology consists of a peer-to-peer network where an append-only ledger is stored and replicated across a peer-to-peer network and offers high tamper-resistance through its consensus protocols. In this thesis, the option of whether the blockchain technology is a suitable solution for synchronizing workflow with its provenance data was explored. A system that generates a workflow, based on a definition written in a Domain Specific Language, was extended to utilize the blockchain technology to synchronize the workflow itself and its results. Furthermore, the InterPlanetary File System was utilized to assist with the versioning of individual executions of the workflow. The InterPlanetary File System provided the functionality of comparing individual workflows executions in more detail and to discover how they differ. The solution was analyzed with respect to the 21 CFR Part 11 regulations imposed by the FDA in order to see how it could assist with fulfilling the requirements of the regulations.  Analysis on the system shows that the blockchain extension can be used to verify if the synchronization between a workflow and its results has been tampered with. Experiments revealed that the size of the workflow did not have a significant effect on the execution time of the extension. Additionally, the proposed solution offers a constant cost in digital currency regardless of the workflow. However, even though the extension shows some promise of assisting with fulfilling the requirements of the 21 CFR Part 11 regulations, analysis revealed that the extension does not fully comply with it due to the complexity of the regulations / I vetenskapliga arbetsflöden är usprung (eng. provenance) av dataviktigt. Genom att spåra ursprunget av data, i form av dokumentation,kan datas ursprung sparas. Detta kan användas för att återskapavetenskapliga experiment eller för att bevisa hur resultat från arbetsflödegenererats. Det är därför viktigt att datas ursprung, som lagrasi ursprungsdatabasen, alltid är synkroniserad med dess motsvarandearbetsflöde som ett sätt att verifiera att ursprungsdatabasen intehar manipulerats. Blockchainteknologi har fått mycket uppmärksamhetde senaste åren sen Satoshi Nakamoto släppte sin Bitcoin artikelår 2009. Blockchainteknologi består av ett peer-to-peer nätverk där endastbifogning tillåts i en liggare som är replikerad över ett peer-topeernätverk vilken tillhandahåller hög manipuleringsresistans genomkonsensusprotokoll. I denna uppsats undersöks hurvida blockchainteknologi är en passande lösning för arbetsflödessynkronisering avursprungsdata. Ett system som genererar ett arbetsflöde, baserat påen definition som skrivits i ett domänspecifikt språk, var förlängt föratt utnyttja blockchainteknologi för synkronisering av arbetsflödet ochdess resultat. InterPlanetary File System användes för att assistera medversionshanteringen av individuella exekveringar av arbetsflödet. InterPlanetaryFile System tillhandahöll funktionalitet för att jämföra individuellaarbetsflödesexekveringar mer detaljerat samt att upptäckahur de skiljer sig åt. Resultaten är analyserade med hänsyn till 21 CFRPart 11 regleringar från FDA för att se hur resultaten kan assistera medatt uppfylla kraven av förordningarna. Analys av systemen visar attblockchainförlängningen kan användas för att verifiera att synkroniseringenmellan arbetsflödet och dess resultat inte har manipulerats.Experimenten visade att storleken av arbetsflödet inte hade märkbareffekt på exekveringstiden av förlängningen. Därutöver möjliggör denpresenterade lösningen en konstant kostnad i digital valuta oavsett arbetsflödetsstorlek. Även om förlängningen visar lovande resultat förassistering av fullföljande av 21 CFR Part 11 regleringarna påvisar analysatt förlängningen inte fullständigt uppfyller kraven på grund avkomplexiteten av dessa regleringar.
145

Blockchain for AI: Smarter Contracts to Secure Artificial Intelligence Algorithms

Badruddoja, Syed 07 1900 (has links)
In this dissertation, I investigate the existing smart contract problems that limit cognitive abilities. I use Taylor's serious expansion, polynomial equation, and fraction-based computations to overcome the limitations of calculations in smart contracts. To prove the hypothesis, I use these mathematical models to compute complex operations of naive Bayes, linear regression, decision trees, and neural network algorithms on Ethereum public test networks. The smart contracts achieve 95\% prediction accuracy compared to traditional programming language models, proving the soundness of the numerical derivations. Many non-real-time applications can use our solution for trusted and secure prediction services.
146

SECURITY RESEARCH FOR BLOCKCHAIN IN SMART GRID

Sang, Lanqin 01 May 2023 (has links) (PDF)
Smart grid is a power supply system that uses digital communication technology to detect and react to local changes for power demand. Modern and future power supply system requires a distributed system for effective communication and management. Blockchain, a distributed technology, has been applied in many fields, e.g., cryptocurrency exchange, secure sharing of medical data, and personal identity security. Much research has been done on the application of blockchain to smart grid. While blockchain has many advantages, such as security and no interference from third parties, it also has inherent disadvantages, such as untrusted network environment, lacking data source privacy, and low network throughput.In this research, three systems are designed to tackle some of these problems in blockchain technology. In the first study, Information-Centric Blockchain Model, we focus on data privacy. In this model, the transactions created by nodes in the network are categorized into separate groups, such as billing transactions, power generation transactions, etc. In this model, all transactions are first encrypted by the corresponding pairs of asymmetric keys, which guarantees that only the intended receivers can see the data so that data confidentiality is preserved. Secondly, all transactions are sent on behalf of their groups, which hides the data sources to preserve the privacy. Our preliminary implementation verified the feasibility of the model, and our analysis demonstrates its effectiveness in securing data source privacy, increasing network throughput, and reducing storage usage. In the second study, we focus on increasing the network’s trustworthiness in an untrusted network environment. A reputation system is designed to evaluate all node’s behaviors. The reputation of a node is evaluated on its computing power, online time, defense ability, function, and service quality. The performance of a node will affect its reputation scores, and a node’s reputation scores will be used to assess its qualification, privileges, and job assignments. Our design is a relatively thorough, self-operated, and closed-loop system. Continuing evaluation of all node’s abilities and behaviors guarantees that only nodes with good scores are qualified to handle certain tasks. Thus, the reputation system helps enhance network security by preventing both internal and external attacks. Preliminary implementation and security analysis showed that the reputation model is feasible and enhances blockchain system’s security. In the third research, a countermeasure was designed for double spending. Double spending is one of the two most concerned security attacks in blockchain. In this study, one of the most reputable nodes was selected as detection node, which keeps checking for conflict transactions in two consecutive blocks. Upon a problematic transaction was discovered, two punishment transactions were created to punish the current attack behavior and to prevent it to happen in future. The experiment shows our design can detect the double spending effectively while using much less detection time and resources.
147

Understanding the Implication of Blockchain Technology on the Audit Profession

Jackson, Brittany 01 January 2018 (has links)
The purpose of this research is to identify the implications of blockchain technology on the auditing profession. By conducting interviews with current professionals in the auditing profession, as well as those in academic with a background in auditing, primary data was collected to aggregate what potential effects will be on the auditing profession in the next five years and the next decade. The data includes assumptions of how the accounting major itself, the auditing planning phase, assumptions of risk, and audit completions will change with the developing technology. The goal of this research is a better understanding of how auditing will be affected by blockchain technology for students, current audit professionals, and those in academia. With the results, it was concluded that training of new and current employees will need to evolve with more emphasis on IT skills and analytical reasoning, blockchain's development is on a precipice of adoption within the next decade, and that there is a current gap regarding regulation of blockchain technology.
148

Hedge Fund Investment in Initial Coin Offerings (ICOs)

Wing, Adam B 01 January 2020 (has links)
Initial Coin Offerings (ICOs) came into worldwide attention in 2018, when over $11.6 billion flowed through them. The CME Group launched Bitcoin futures contracts in December 2017, giving large funds their first regulated exposure to digital assets. As digital assets move towards the mainstream of finance, institutional investors have followed. This study comparatively analyzes Hedge Fund investment in digital assets against that of other institutional investment firm types (Private Equity and Venture Capital) by analyzing their crypto holdings and rebuilding an equally weighted portfolio for each fund. Under these conditions, the study succeeds in finding significant differences between hedge fund results in the sample and those of private equity/venture capital firms. Specifically, this study shows through the composite portfolios built that digital asset investments made by hedge funds generate a much higher return than that of private equity and venture capital firms. Average hedge fund investments have much higher trading volumes and market capitalizations than those made by private equity and venture capital firms, suggesting that PE and VC firms are taking higher risks by investing in new and little-known crypto projects. The results of this study signal that the hedge fund business model is much better suited for the high-risk, high-volatility cryptocurrency market than strategies employed by venture capital and private equity firms.
149

Voter Competency, Distributed Ledger Technology, and the Future of Democracy

Ramsay, Travis January 2019 (has links)
A great challenge for democracy is to account for the conflict between the ideal of self-governance and the capacity of the average person to participate in democratic decision-making. This challenge has led some observers to question the defensibility of democracy and consider other systems of social organization. I argue instead that the problem can be solved with a technologically enhanced version of Thomas Christiano’s choice of aims model of democracy. I begin by setting up the voter competency problem: I describe the ideals of democracy and the role that is ascribed to citizens under traditional accounts of democracy, then proceed to a discussion of the empirical evidence that shows how unlikely it is that voters could ever adequately perform such a role. While I consider a number of alternative democratic models which attempt to reconstruct the role of citizens in a way that is consistent with their capacities and with the democratic ideal of self-governance, I find that the choice of aims model strikes this balance in a way that is most tenable. Despite this, I argue that changes to the way information is distributed in modern democracies, to do with the rise of the internet, pose a serious threat to the viability of even this model, as it is becoming increasingly difficult for voters to ascertain reliable information. The second half of the thesis offers support to Christiano’s model in the form of technologically enhanced institutions. Chapter 3 provides a basic understanding of an emerging technology called distributed ledger technology, which offers a new paradigm for how information is stored, controlled, and distributed around society. The final chapter demonstrates how this technology can be used to strengthen democratic institutions so that citizens are able to truly be said to self-govern in a way that is consistent with their capacities. / Thesis / Master of Arts (MA)
150

Automated labeling of unknown contracts in Ethereum

Norvill, R., State, R., Awan, Irfan U., Pontiveros, B.B.F., Cullen, Andrea J. 07 1900 (has links)
yes / Smart contracts have recently attracted interest from diverse fields including law and finance. Ethereum in particular has grown rapidly to accommodate an entire ecosystem of contracts which run using its own crypto-currency. Smart contract developers can opt to verify their contracts so that any user can inspect and audit the code before executing the contract. However, the huge numbers of deployed smart contracts and the lack of supporting tools for the analysis of smart contracts makes it very challenging to get insights into this eco-environment, where code gets executed through transactions performing value transfer of a crypto-currency. We address this problem and report on the use of unsupervised clustering techniques and a seed set of verified contracts, in this work we propose a framework to group together similar contracts within the Ethereum network using only the contracts publicly available compiled code. We report qualitative and quantitative results on a dataset and provide the dataset and project code to the research community. / Link to conference webpage: http://icccn.org/icccn17/workshop/

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