Since the introduction of Bitcoin, numerous studies on Bitcoin mining attacks have been conducted, and as a result, many countermeasures to these attacks have been proposed. The reputation-based mining paradigm is a comprehensive countermeasure solution to this problem with the goal of regulating the mining process and preventing mining attacks. This is accomplished by incentivizing miners to avoid dishonest mining strategies using reward and punishment mechanisms. This model was validated solely based on game theoretical analyses and the real-world implications of this model are not known due to the lack of empirical data. To shed light on this issue, we designed a simulated mining platform to examine the effectiveness of the reputation-based mining paradigm through data analysis. We implemented block withholding attacks in our simulation and ran the following three scenarios: Reputation mode, non-reputation mode, and no attack mode. By comparing the results from these three scenarios, interestingly we found that the reputation-based mining paradigm decreases the number of block withholding attacks, and as a result, the actual revenue of individual miners becomes closer to their theoretical expected revenue. In addition, we observed that the confidence interval test can effectively detect block withholding attacks however, the test also results in a small number of false positive cases. Since the effectiveness of the reputation-based model relies on attack detection, further research is needed to investigate the effect of this model on other dishonest mining strategies. / Includes bibliography. / Thesis (MS)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

The Blockchain concept was originally developed to provide security in the Bitcoin cryptocurrency network, where trust is achieved through the provision of an agreed-upon and immutable record of transactions between parties. The use of a Blockchain as a secure, publicly distributed ledger is applicable to fields beyond finance, and is an emerging area of research across many other fields in the industry. This thesis considers the feasibility of using a Blockchain to facilitate secured information sharing between parties, where a lack of trust and absence of central control are common characteristics. Implementation of a Blockchain Information Sharing system will be designed on an existing Blockchain network with as a communicative party members sharing secured information. The benefits and risks associated with using a public Blockchain for information sharing will also be discussed. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

A research article submitted to the Faculty of Commerce, Law and Management, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Business Administration Johannesburg, 2018 / Blockchain technology is a foundational technology with various use cases that can significantly impact the manner in which banking is carried out in South Africa. The following paper seeks to put together a framework for understanding the potential effect of blockchain technology on the South African banking environment, with a specific focus on how blockchain technology will impact the South African banking environment (i.e. the applications and use cases) and when this impact will take place. A qualitative approach to addressing the problem statement was adopted, specifically in the form of focus interviews and strategic discussions with subject matter experts in both the blockchain and South African banking environment. Findings indicate that there are number of blockchain applications that can impact the South African banking environment namely, Private Digital Ledgers, Smart Contracts and Tokens/ Cryptocurrencies. Further to this, research indicates that the former is most likely in the short term, while the latter two applications are subject to a high-level stakeholder coordination, a high level of effort in educating the end customer and a high level of friction from existing systems and process, and will therefore only realise mass adoption in the long-term. As a result, this research contributes to providing an initial view of which applications are most likely to be adopted by South African banks and can form the foundation for further research in this area. / E.K. 2019

We aim to identify factors that are critical in determining whether or not blockchain adoption arises in various market structures, and give guidance for addressing the challenges of blockchain implementation. In Chapter 2, we construct an economic framework for understanding the incentives of the firms in a supply chain to form a blockchain consortium. We find that blockchain reduces information asymmetry for consumers, thereby enhancing consumer welfare. Consumer welfare gains can be sufficiently large that blockchain adoption is socially beneficial; nonetheless, we find that blockchain adoption does not arise in equilibrium. This situation arises because blockchain adoption costs are borne by manufacturers, and manufacturers cannot extract consumer gains through prices due to the competitive nature of the manufacturing sector. We offer a system of transfers to generate blockchain adoption in equilibrium when it is socially beneficial. In Chapter 3, we investigate a variation of the model described in Chapter 2. Our analysis incorporates the blockchain’s ability to trace shipments and generate cost savings for the manufacturers who join the blockchain. Although the blockchain enables early recalls of defective goods with higher probability, and thus, reduces expected unit costs for all the manufacturers on the blockchain, such gains are still competed away and blockchain adoption does not arise in equilibrium. This result strengthens our earlier findings on the incentive misalignment in a perfectly competitive setting. The associated welfare implications of this model are similar to those in Chapter 2. In Chapter 4, we study a setting in which the consumer prices are determined exogenously. With this setting of sticky price, there exists a certain level of competition but it is not perfect. As a result, the manufacturer gains from blockchain adoption may be strictly positive, in contrast to two results in Chapters 2 and 3 where the gains are always competed away. We find that blockchain unequivocally benefits consumers but has an ambiguous effect upon the welfare of manufacturers. There exist conditions under which, although the blockchain improves global welfare, blockchain adoption does not arise in equilibrium. We refer to such a scenario as an adoption failure, and again a system of transfers is proposed to resolve that failure. In Chapter 5, we examine whether blockchain adoption arises in equilibrium for a supply chain in which a single risk-averse manufacturer sells directly to consumers; thus, the manufacturer possesses market power. In this setting, we find that blockchain adoption always enhances manufacturer welfare when the adoption cost is zero. While two results in Chapters 2 and 3 demonstrate that blockchain adoption does not arise when the manufacturing sector is perfectly competitive, our findings clarify that the failure of blockchain adoption is not generic across all market structures. Rather, blockchain adoption arises in equilibrium for supply chains when the manufacturer possesses market power and when the adoption cost is sufficiently small.