Blockchain is a technology that allows the decentralization of data stored in a way that there is no single central actor to control or modify the data. Bitcoin is the first successful blockchain application implemented with the concept known as cryptocurrency that allows a transaction flow without any bank or government to control it. Blockchain is associated with benefits including high level of transparency, integrity, trust and confidence for the participants. Blockchain is still at early stage but it is a promising technology that has the potential to impact many more areas in the future. However, its security area is still the weakest part of it which still needs improvement. Therefore, this thesis aims to make a review of the blockchain security issues using the past published literature between 2010 and 2021. This thesis conducts a review on 20 articles to provide a scientific input that gives an overall view of existing security threats and their respective impacts on blockchain system. This thesis starts with an overview of how blockchain system works and briefly discuss on the information security of blockchain. The collection of security attacks from the literature has been carried out by using concept centric matrix approach. This process resulted to security attacks that were classified based on four layers of blockchain system architecture. Then, the security attacks are mapped to common security impacts including double spending, unauthorized code execution, denial of service, unfair income and privacy key leakage. These security impacts were analyzed which led to the conclusion that the major security issues on blockchain result from its P2P network architecture and its consensus mechanism. Besides, some possible solutions to mitigate the security threats were discussed though, more effort in developing new security measures and protocol framework is still required.

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

No / Research studies report that there are a growing number of falsified educational certificates being produced by dishonest job seekers and higher education applicants across the world. Technological development in the image-processing domain makes editing the document so simple that any individual can perform this kind of forgery without having high-level skills in image editing. Most national governments have put in place stringent policies and procedures to verify and authenticate academic documents. However, due to the amount of human intervention in the process, the efficiency of such measures is debatable. Such systems leave open the possibility that unethical insiders may engage in forgery. In addition, the process of document verification and authentication consumes substantial amounts of time and money. Existing systems of document attestation do not provide a simple and instant way of verifying the authenticity of certificates from transcript level onward. In response to the above issues, this project proposes a prototype model for digitally managing and attesting the academic records using permissioned blockchain technology. By this method, the block-chaining of a student record begins from the time of admission to the Higher Education Institute (HEI) and continues to record the academic progress until graduation, having the graduation details stored as the last block in the chain. The whole blockchain of the student record will remain in the system with the participants enabling any indirect stakeholder to verify the details instantly based on the hash code or QR code. Additional privileges will be provided for direct stakeholders such as (here in Oman) the Ministry of Manpower and the Ministry of Higher Education to access further details of the certificate-holder. The system includes the student as a stakeholder and also as a participant to ensure transparency for her/his academic records.

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.

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.

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.

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.

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)

The adoption of blockchain technologies require the consideration of a broad range of factors, over and above the predominantly technology focus of most current work. Whilst scholarly literature on blockchain technology is only beginning to emerge, majority are focused on the technicalities of the technology and tend to ignore the organizational complexities of adopting the technology. Drawing from a focused review of literature, this paper proposed a conceptual framework for adoption of blockchain technology capturing the complex relationships between institutional, market and technical factors. The framework highlights that varying outcomes are possible, and the change process is focal as this shapes the form blockchain applications take. Factors presented in the framework (institutional, market and technical) interact and mutually influence each other. The proposed framework can be used by organisations as a reference point for adopting blockchain applications and by scholars to expand, refine and evaluate research into blockchain technology.

The growing reliance on digital services has led to an escalation in cyber risks and attacks targeting banks and financial institutions. Such cyber threats necessitate innovative solutions. But to achieve it, one needs to overcome the challenges of seeking reliable information on utilizing blockchain technology to combat cyber-attacks. Hence, this work aims to use a systematic literature review to study the potential of blockchain technology to mitigate cyber threats in the banking and financial sector as well as the advantages and challenges of blockchain technology. Blockchain provides heightened security, improv transaction processes, ensures transparency and privacy, optimizes operational performance, and reduces fraud. Despite its advantages, challenges like regulatory compliance, privacy concerns, and scalability need careful consideration. Prominent institutions like Bank of America, HSBC, and J.P. Morgan are actively investigating blockchain integration. To ensure wise choices regarding blockchain use in organizations with valuable data and assets, advisors and business leaders must fully grasp both the advantages and possible drawbacks of this technology. Armed with this information, financial institutions gain essential insights, steering them towards judicious choices concerning the integration and utilization of blockchain technology, thereby enhancing, and reinforcing their cybersecurity framework. / Den ökande användningen av digitala tjänster har resulterat i en ökning av cyberrisker och attacker riktade mot banker och finansinstitutioner. Cyberhot fortsätter att utmana säkerheten för finansiella institutioner, vilket kräver nyskapande lösningar. För att uppnå det måste man övervinna utmaningarna med att söka tillförlitlig information angående användningen av blockkedja teknik för att bekämpa cyberattacker. Därför syftar detta verk till att använda systematisk litteraturgenomgång för att utforska potentialen hos blockkedjeteknik för att mildra cyberhot inom bank- och finanssektorn, samt för- och nackdelar med teknologin. Blockkedja teknik erbjuder förhöjd säkerhet, optimerar transaktionsprocessen, säkerställer transparens och integritet, ökar operativ prestanda och minskar risken för bedrägeri. Trots dessa fördelar måste utmaningar som regeluppfyllelse, integritetsfrågor och skalbarhet hanteras med omsorg. Framstående institutioner som Bank of America, HSBC och J.P. Morgan undersöker aktivt integration av blockkedja teknik. För att säkerställa kloka beslut kring blockkedjeanvändning i organisationer med viktig information och tillgångar är det avgörande att rådgivare och företagsledare har en djup förståelse för både fördelar och möjliga nackdelar med teknologin. Med denna insikt i ryggen får finansinstitutioner värdefull vägledning när det gäller integration och användning av blockkedjeteknik, vilket stärker och förbättrar deras ramverk för cybersäkerhet.