This thesis deals with cryptocurrencies and the underlying principles they are based on. It describes the blockchain technology and explores various cryptocurrencies that utilize it with the focus on their similarities and differences. The next part analyzes InsightAPI, the existing tool for real-time Bitcoin blockchain exploration. It then describes the proposed solution for the Ethereum blockchain explorer, highlights the implementation details, and shows results of its testing. The created tool allows the user to quickly gather information about desired blocks, users, and transactions of the Ethereum blockchain.

Blockchain technology brings new opportunities and has the ability to solve current flaws with our traditional central systems, still, blockchain is not a common practice. This thesis revolves around vital factors that affect the implementation of blockchain (BC) technology in modern business. By identifying the potential advantages for BC systems, we look at why BC systems are not commonly applied in organizations. There seem to be several factors within three categories; technological, organizational, and environmental (TOE) that serve as obstacles or opportunities for the modern business to adopt blockchain technology despite the apparent advantages that the innovation promotes. The purpose is to identify what factors from a TOE perspective play a decisive role in the adoption process of innovations, in this case, BC. The aim is to confirm factors from previous research and contribute with new factors within the TOE framework that can assist modern business in the adoption process. Empirical data of this thesis are derived from interviews from various organizations from different industries, which is analyzed by content analysis method.  The main limitation of this thesis is the lack of knowledge regarding BC technology among employees of organizations. A significant challenge has been to find possible interview participants to collect data necessary for the research question.  Despite that, we succeeded in collecting enough data to be able to answer our research question. This thesis confirms and contributes to new factors in the field of blockchain adoption in modern business.

abstract: Large organizations have multiple networks that are subject to attacks, which can be detected by continuous monitoring and analyzing the network traffic by Intrusion Detection Systems. Collaborative Intrusion Detection Systems (CIDS) are used for efficient detection of distributed attacks by having a global view of the traffic events in large networks. However, CIDS are vulnerable to internal attacks, and these internal attacks decrease the mutual trust among the nodes in CIDS required for sharing of critical and sensitive alert data in CIDS. Without the data sharing, the nodes of CIDS cannot collaborate efficiently to form a comprehensive view of events in the networks monitored to detect distributed attacks. The compromised nodes will further decrease the accuracy of CIDS by generating false positives and false negatives of the traffic event classifications. In this thesis, an approach based on a trust score system is presented to detect and suspend the compromised nodes in CIDS to improve the trust among the nodes for efficient collaboration. This trust score-based approach is implemented as a consensus model on a private blockchain because private blockchain has the features to address the accountability, integrity and privacy requirements of CIDS. In this approach, the trust scores of malicious nodes are decreased with every reported false negative or false positive of the traffic event classifications. When the trust scores of any node falls below a threshold, the node is identified as compromised and suspended. The approach is evaluated for the accuracy of identifying malicious nodes in CIDS. / Dissertation/Thesis / Masters Thesis Computer Science 2020

Magister Legum - LLM / Our lives, work, and behaviour have been changed both positively and negatively by the digital presence that has grown tremendously over the last three decades, and with this exponential growth, we cannot predict where we will be, digitally-speaking, in the years to come. As it stands in South Africa and the majority of the world today, we find that the law is yet to catch up to the technological explosion, in particular to the concept of digital assets. Digital material that is produced and purchased form a big part of our daily lives as we continue to consume media online, use social media platforms, and invest in cryptocurrency. The question of whether South African law makes sufficient provision for the incorporation of digital assets and, in particular, cryptocurrency in inter vivos or testamentary trust is yet to be fully established.

>Magister Scientiae - MSc / With the development of information and network technologies, Electronic Health Records (EHRs) management system has gained wide spread application in managing medical records. One of the major challenges of EHRs is the independent nature of medical institutions. This non-collaborative nature puts a significant barrier between patients, doctors, medical researchers and medical data. Moreover, unlike the unique and strong anti-tampering nature of traditional paper-based records, electronic health records stored in centralization database are vulnerable to risks from network attacks, forgery and tampering. In view of the data sharing difficulties and information security problems commonly found in existing EHRs, this dissertation designs and develops a credible Blockchain-based electronic health records (CB-EHRs) management system.

Today's paper-based system regarding share certificates has long been considered obsolete in relation to the technical development that characterizes an otherwise digital market. Especially in relation to the inconveniences the system is associated with for limited liability companies, as well as for the shareholders.  Despite it being a known fact, no changes have been made in cases where amendments to the law have been discussed through official government reports. The solutions presented in the reports have been either an implementation of a share register or an extended function of the share ledger, both requiring the abolishment of share certificates. The opinion yet remained that the positive aspects of the paper-based share certificate system overweighed the negative ones due to technological shortcomings. However, in light of recent development in modern technology, a solution might be found in blockchain technology. The overall question of this thesis is thus to what extent the paper-based system raises problems and whether satisfactory solutions can be found in new technology. In order to present effective and competitive solutions, the thesis looks beyond the national boarders, towards foreign judicial system to find alternative ways of handling the issue of share certificates. Through the international perspective, blockchain technology is presented as a potential solution. In order to assess its compatibility with the Swedish judicial system a short introduction is made regarding the underlying technology. This also helps create an understanding of its pioneering nature. The technical introduction is then followed by a theoretical application of a blockchain-based solution for handling the share certificates as well as the share ledger. This leads to the conclusion that a potential solution is found in blockchain technology which, combined with the overall assessment of the negative aspects of a paper-based system, advocates for a reform.

Financial Aspects of Alternative Payment Systems from the Point of View of Money Laundering Abstract The aim of this thesis is to provide a general overview of the current state of alternative payment systems with regard to their inclusion in the financial market, their properties and potentials for wider use, and to evaluate their possibilities to more effectively combat money laundering, terrorist financing and the proliferation of weapons of mass destruction. In the first chapter, the thesis explains the broader context with regard to financial systems, especially within the money market systems focusing on retail, while providing a deeper explanation of the context of European law and Czech law. The second chapter is focused on closer analysis of alternative payment systems with regard to their use. Alternative payment systems are divided into two basic categories for centralized alternative payment systems and decentralized alternative payment systems. The category of centralized alternative payment systems corresponds to the current conventional financial market, taking into account the innovations that have emerged in recent years. Decentralized alternative payment systems are based on the DLT Blockchain technology and the Islamic Hawala payment system is analyzed as a purely informal, decentralized...

Today's society has grown to be highly digitalized where technologies are playing a large role in everyone's lives. Moreover, society is still developing at a rapid pace, with a new innovation around every corner and with more and more business conducted online. By using this as a starting point, the authors of this thesis choose to examine how blockchain can influence the use of big data in digital marketing. Moreover, as previous articles have perceived GDPR as an obstacle for implementing blockchain within this context, the authors perceived it as necessary to examine blockchains’ relation to GDPR. Thus, this thesis has set out to both identify challenges and opportunities that exist when applying blockchain within the context of digital marketing. This exploratory thesis applies a qualitative data collection method in order to fulfill the purpose of the study and to answer the following components of the research question; (1) How will blockchain influence the use of big data within digital marketing? (2) How will blockchain in a digital marketing context cope with the regulations of GDPR? (3) How will blockchain influence the future of digital marketing? The qualitative collection method chosen is semi-structured interviews and has included six participants from Europe.  The findings of this thesis suggest that blockchain will influence big data and thus, digital marketing will be influenced because it is heavily data-driven. Furthermore, blockchain will influence the companies’ knowledge of the customer, allow more reliable data to be obtained, and allow consumers to retain ownership over their data. Thus, blockchain places a higher demand on companies to deliver relevant information and match the interest of customers in order for the companies to gain access to customers’ data. Additionally, the findings suggest that blockchain has the ability to remove intermediaries and eliminate fraudulent activities, such as deep fakes, illegitimate reviews, click-fraud, within digital marketing. Despite that blockchain has a lot of potentials, it also faces a lot of challenges and obstacles. For instance, large companies such as Google may feel threatened by the blockchain and thus, these companies may have incentives for disrupting the implementation of the technology. Moreover, practical challenges have been identified. These were related to non-scalable algorithms and limited capacities to store large amounts of data.

The implementation of internet of things is plagued by problems such as security and scalability. It is a very heterogeneous environment and overcoming these hurdles is therefore not an easy feat. A concept of using the decentralized and secure nature of the blockchain technology to combat these problems have been identified. However the stark contrast of blockchain technology being resource hungry and internet of things devices being resource depraved is among other things a new hurdle that is introduced. This systematic literature study aimed to identify problems that a rose when trying to merge these technologies while focusing on the authentication aspect.Smart contracts play a huge role in making most of the identified solutions at least feasible to implement on a larger scale. While most systems have solved the authentication problem the major problems of the blockchain adaptation for internet of things remains unsolved. Three solutions were identified that really try to combat these problems by changing the blockchain technology at its core while the rest feel like they are trying to do the best with what is available and falls short in some major way.

The increasingly adapted technology called blockchain can be viewed as a distributed append-only time-stamped data structure which is made possible by a distributed peer-to-peer network. The network uses cryptography and different consensus mechanisms to ensure immutability, security, transparency, and speed in a decentralized fashion. A permissionless decentralized autonomous organization (DAO) is an application deployed on a blockchain that enables people to govern and coordinate themselves in a decentralized manner through self-executing rules where anyone can join. A foundational function of a DAO is the voting system which dictates how the governance of the DAO is conducted. Voting systems in DAOs are currently not well researched and the currently used solutions have flaws, they are either not secure or they have the risk of resulting in unfair outcomes. This is the problem that this project focuses on. The problem was approached by conducting research in the field and through the conclusions of the research a new solution for a voting system was proposed and implemented. The proposed solution can be used to gain inspiration in further studies or be tested and developed to evaluate it in practice.