What Does Not Fit Can be Made to Fit! Trade-Offs in Distributed Ledger Technology Designs

Distributed ledger technology (DLT), including blockchain, enables secure processing of transactions between untrustworthy parties in a decentralized system. However, DLT is available in different designs that exhibit diverse characteristics. Moreover, DLT characteristics have complementary and conflicting interdependencies. Hence, there will never be an ideal DLT design for all DLT use cases; instead, DLT implementations need to be configured to contextual requirements. Successful DLT configuration requires, however, a sound understanding of DLT characteristics and their interdependencies. In this manuscript, we review DLT characteristics and organize them into six groups. Furthermore, we condense interdependencies of DLT characteristics into trade-offs that should be considered for successful deployment of DLT. Finally, we consolidate our findings into DLT archetypes for common design objectives, such as security, usability, or performance. Our work makes extant DLT research more transparent and fosters understanding of interdependencies and trade-offs between DLT characteristics

Quality of Service improvements for real time multimedia applications using next generation network architectures and blockchain in Internet Service Provider cooperative scenario

Real time communications are becoming part of our daily life, requiring constrained requisites with the purpose of being enjoyed in harmony by end users. The factors ruling these requisites are Quality of Service parameters of the users' Internet connections. Achieving a satisfactory QoS level for real time communications depends on parameters that are strongly influenced by the quality of the network connections among the Internet Service Providers, which are located in the path between final users and Over The Top service providers that are supplying them with real time services. Final users can be: business people having real time videoconferences, or adopting crytpocurrencies in their exchanges, videogamers playing online games together with others residing in other countries, migrants talking with their relatives or watching their children growing up in their home countries, people with disabilities adopting tecnologies to help them, doctors performing remote surgeries, manufacturers adopting augmented reality devices to perform dangerous tasks. Each of them performing their daily activities are requiring specific QoS parameters to their ISPs, that nowadays seem to be unable to provide them with a satisfactory QoS level for these kinds of real time services. Through the adoption of next generation networks, such as the Information Centric Networking, it would be possible to overcome the QoS problems that nowadays are experienced. By adopting Blockchain technologies, in several use cases, it would be possible to improve those security aspects related to the non-temperability of information and privacy. I started this thesis analyzing next generation architectures enabling real time multimedia communications. In Software Defined Networking, Named Data Networking and Community Information Centric Networking, I highlighted potential approaches to solve QoS problems that are affecting real time multimedia applications. During my experiments I found that applications able to transmit high quality videos, such as 4k or 8k videos, or to directly interact with devices AR/VR enabled are missing for both ICN approaches. Then I proposed a REST interface for the enforcing of a specific QoS parameter, the round trip time (RTT) taking into consideration the specific use case of a game company that connects with the same telecommunication company of the final user. Supposing that the proposed REST APIs have been deployed in the game company and in the ISP, when one or more users are experiencing lag, the game company will try to ask the ISP to reduce the RTT for that specific user or that group of users. This request can be done by performing a call to a method where IP address(es) and the maximum RTT desired are passed. I also proposed other methods, through which it would be possible to retrieve information about the QoS parameters, and exchange, if necessary, an exceeding parameter in change of another one. The proposed REST APIs can also be used in more complex scenarios, where ISPs along the path are chained together, in order to improve the end to end QoS among Over The Top service provider and final users. To store the information exchanged by using the proposed REST APIs, I proposed to adopt a permissioned blockchain, analizying the ISPs cooperative use case with Hyperledger Fabric, where I proposed the adoption of the Proof of Authority consensus algorithm, to increase the throughput in terms of transactions per second. In a specific case that I examined, I am proposing a combination of Information Centric Networking and Blockchain, in an architecture where ISPs are exchanging valuable information regarding final Users, to improve their QoS parameters. I also proposed my smart contract for the gaming delay use case, that can be used to rule the communication among those ISPs that are along the path among OTT and final users. An extension of this work can be done, by defining billing costs for the QoS improvements

A PoW-less Bitcoin with Certified Byzantine Consensus

Distributed Ledger Technologies (DLTs), when managed by a few trusted validators, require most but not all of the machinery available in public DLTs. In this work, we explore one possible way to profit from this state of affairs. We devise a combination of a modified Practical Byzantine Fault Tolerant (PBFT) protocol and a revised Flexible Round-Optimized Schnorr Threshold Signatures (FROST) scheme, and then we inject the resulting proof-of-authority consensus algorithm into Bitcoin (chosen for the reliability, openness, and liveliness it brings in), replacing its PoW machinery. The combined protocol may operate as a modern, safe foundation for digital payment systems and Central Bank Digital Currencies (CBDC)

Blockchain for agriculture and food : Findings from the pilot study

This report documents experiences and findings from the public private partnership (PPP) project ‘Blockchain for Agrifood’ that was started in March 2017. The project aims to contribute to a better understanding of the blockchain technology (BCT) and its implications for agrifood, especially how it can impact specific aspects of supply chains and what is needed to apply BCT in agrifood chains. A second aim of this project is to conceptualise and develop a proof of concept in an application based on a use case concerning table grapes from South Africa where BCT could be applied. This has been done by building a demonstrator that keeps track of different certificates involved in the table grapes supply chain. The code of this demonstrator is published at Github. Furthermore, the project explored issues regarding the relevance, applicability and implications of BCT for the agrifood sector through literature study and stakeholder consultation

Blockchain Value Creation Logics and Financial Returns

With its complexities and portfolio-nature, the advent of blockchain technology presents several use cases to stakeholders for business value appropriation and financial gains. This 3-essay dissertation focuses on three exemplars and research approaches to understanding the value creation logics of blockchain technology for financial gains. The first essay is a conceptual piece that explores five main affordances of blockchain technology and how these can be actualized and assimilated for business value. Based on the analysis of literature findings, an Affordance-Experimentation-Actualization-Assimilation (AEAA) model is proposed. The model suggests five affordance-to-assimilation value chains and eight value interdependencies that firms can leverage to optimize their value creation and capture during blockchain technology implementation. The second essay empirically examines the financial returns of public firms\u27 blockchain adoption investments at the level of the three main blockchain archetypes (private-permissioned, public-permissioned and permissionless. Drawing upon Fichman\u27s model of the option value of innovative IT platform investments, the study examines business value creation through firm blockchain strategy (i.e., archetype instances, decentralization, and complementarity), learning (i.e., blockchain patents and event participation), and bandwagon effects using quarterly data of firm archetype investments from 2015 to 2020. The study\u27s propensity score matching utilization and fixed-effects modeling provide objective quantification of how blockchain adoption leads to increases in firm value (performance measured by Tobin\u27s q) at the archetype level (permissionless, public permissioned, and private permissioned). Surprisingly, a more decentralized archetype and a second different archetype implementation are associated with a lower Tobin\u27s q. In addition, IT-option proxy parameters such as blockchain patent originality, participation in blockchain events, and network externality positively impact firm performance, whereas the effect of blockchain patents is negative. As the foremost and more established use case of blockchain technology whose business value is accessed in either of the five affordances and exemplifies a permissionless archetype for financial gains, bitcoin cryptocurrency behavior is studied through the lens of opinion leaders on Twitter. The third essay this relationship understands the hourly price returns and volatility shocks that sentiments from opinion leaders generate and vice-versa. With a dynamic opinion leader identification strategy, lexicon and rule-based sentiment analytics, I extract sentiments of the top ten per cent bitcoin opinion leaders\u27 tweets. Controlling for various economic indices and contextual factors, the study estimates a vector autoregression model (VAR) and finds that finds that Bitcoin return granger cause Polarity but the influence of sentiment subjectivity is marginal and only stronger on bitcoin price volatility. Several key implications for blockchain practitioners and financial stakeholders and suggestions for future research are discussed

Conceptualizing Blockchain in The Music Industry

As blockchain technology continues to evoke interest and engagement across companies, organizations, industries, and governments, the desire to integrate the technology is evident. The discussion around blockchain often implies promises of decentralization, transparency, and disruption. The music industry specifically has been noted to potentially gain from the implementation of blockchain, making it a great context for exploration: the industry is constructed of multiple stakeholders with complicated and often dysfunctional connections. This research aims to understand how blockchain is utilized in the context of music industry. It distinctively tries to understand the technical structure of the applied blockchain, the implications to business logic and structures, and lastly the long-term intersection of blockchain and the music industry. This research was conducted as a qualitative multiple-case study. With an inductive and intensive approach, the objective was to explore the use of blockchain in a holistic nature from the perspective of each case. The empirical data was collected from secondary whitepapers published by each case company. Each whitepaper detailed the technical and the business structure as it pertains to blockchain. The data revealed how blockchain governs engagement and the positioning of each stake-holder in the ecosystem and in relation to each other in the presence, or lack thereof, of blockchain. It was concluded that blockchain can be utilized in varying ways and to varying degrees. The consequential effects can be observed in the governance, structure, and business logic of each case, which this research showcases in detail. While this research was able to provide differing possibilities for use, it could not provide evidence of blockchain being mature enough for mass adoption, supporting arguments presented in previous research and theory.Blockchain-teknologian noustessa yhä tunnetummaksi, monen yrityksen ja tahon tavoitteena on tutkia tämän teknologian hyödyntämistä. Musiikkiteollisuus on erityisesti mainittu sopivan kyseiseen integroimiseen: musiikkiteollisuudessa on monia sidosryhmiä, joiden välillä on monimutkaisia ja usein ongelmallisia suhteita. Tämän tutkimuksen tavoitteena on ymmärtää blockchain-teknologian käyttö musiikkiteollisuudessa. Ymmärrys ulottuu tekniseen hyödyntämiseen, liiketoiminnallisiin seuraamuksiin ja musiikkiteollisuuden ja teknologian pitkäaikaiseen risteytymään. Tutkimus suoritettiin laadullisena monitapaustutkimuksena, jonka tarkoituksena oli kerätä kokonaisvaltainen ymmärrys blockchain-teknologian käytöstä jokaisen tapauksen näkökulmasta. Empiirinen data kerättiin sekundääriaineistosta, josta tuli ilmi jokaisen tapauksen tekninen ja liiketoiminnallinen malli. Aineistoa lähestyttiin induktiivisesti ja analysoitiin intensiivisesti. Tulokset paljastivat kuinka blockchain-teknologia ohjasi kanssakäymistä ja miten eri sidosryhmät asennoituivat teknologiaan ja toisiinsa nähden. Teknologiaa hyödynnettiin eri tavoilla ja eri laajuudella. Teknologian seurauksena jokaisessa tapauksessa ilmestyi huomattavia eroja tapausten hallinnoinnissa, rakenteissa ja liiketoiminnan logiikassa. Tämä tutkimus erittelee tarkasti jokaisen tapauksen tekniset yksityiskohdat ja niistä seuraavat edellä mainitut erot. Johtopäätöksenä kuitenkin todetaan, että tutkimuksessa esiintyvät tapaukset ovat vielä kehittymisvaiheessa, eivätkä voi näin puoltaa teknologian olevan valmiina täysmittaiseen adoptioon. Tämä osaltaan tukee teoriassa esiin tuotuja väitteitä teknologian epäkypsyydestä

Blockchain's adoption in IoT: The challenges, and a way forward

© 2018 Elsevier Ltd The underlying technology of Bitcoin is blockchain, which was initially designed for financial value transfer only. Nonetheless, due to its decentralized architecture, fault tolerance and cryptographic security benefits such as pseudonymous identities, data integrity and authentication, researchers and security analysts around the world are focusing on the blockchain to resolve security and privacy issues of IoT. However, presently, not much work has been done to assess blockchain's viability for IoT and the associated challenges. Hence, to arrive at intelligible conclusions, this paper carries out a systematic study of the peculiarities of the IoT environment including its security and performance requirements and progression in blockchain technologies. We have identified the gaps by mapping the security and performance benefits inferred by the blockchain technologies and some of the blockchain-based IoT applications against the IoT requirements. We also discovered some practical issues involved in the integration of IoT devices with the blockchain. In the end, we propose a way forward to resolve some of the significant challenges to the blockchain's adoption in IoT

DESIGN AND EXPLORATION OF NEW MODELS FOR SECURITY AND PRIVACY-SENSITIVE COLLABORATION SYSTEMS

Collaboration has been an area of interest in many domains including education, research, healthcare supply chain, Internet of things, and music etc. It enhances problem solving through expertise sharing, ideas sharing, learning and resource sharing, and improved decision making. To address the limitations in the existing literature, this dissertation presents a design science artifact and a conceptual model for collaborative environment. The first artifact is a blockchain based collaborative information exchange system that utilizes blockchain technology and semi-automated ontology mappings to enable secure and interoperable health information exchange among different health care institutions. The conceptual model proposed in this dissertation explores the factors that influences professionals continued use of video- conferencing applications. The conceptual model investigates the role the perceived risks and benefits play in influencing professionals’ attitude towards VC apps and consequently its active and automatic use