A Quality-of-Service Compliance System using Federated Learning and Optimistic Rollups

Edge computing brings a new paradigm in which the sharing of computing, storage, and bandwidth resources as close as possible to the mobile devices or sensors generating a large amount of data. A parallel trend is the rise of phones and tablets as primary computing devices for many people. The powerful sensors present on these devices combined with the fact that they are mobile, mean they have access to data of an unprecedentedly diverse and private nature. Models learned on such data hold the promise of greatly improving usability by powering more intelligent applications, but the sensitive nature of the data means there are risks and responsibilities to storing it in a centralized location. To address the data privacy required for some data in these devices we propose the use of Federated Learning (FL) so that specific data about services performed by clients do not leave the source machines. Instead of sharing data, users collaboratively train a model by only sending weight updates to a server. However, the naive use of FL in those scenarios exposes it to a risk of corruption, whether intentional or not, during the training phase. To improve the security of the FL structure, we propose a decentralized Blockchain-based FL in an edge computing scenario. We also apply blockchain to create a reward mechanism in FL to enable incentive strategy for trainers

Beyond oracles – a critical look at real-world blockchains

This thesis intends to provide answers to the following questions: 1) What is the oracle problem, and how do the limitations of oracles affect different real-world applications? 2) What are the characteristics of the portion of the literature that leaves the oracle problem unaddressed? 3) Who are the main contributors to solving the oracle problem, and which issues are they focusing on? 4) How can the oracle problem be overcome in real-world applications? The first chapter aims to answer the first question through a literature review of the most current papers published in the field, bringing clarity to the blockchain oracle problem by discussing its effects in some of the most promising real-world blockchain applications. Thus, the chapter investigates the sectors of Intellectual Property Rights (IPRs), healthcare, supply chains, academic records, resource management, and law. By comparing the different applications, the review reveals that heterogeneous issues arise depending on the sector. The analysis supports the view that the more trusted a system is, the less the oracle problem has an impact. The second chapter presents the results of a systematic review intended to highlight the state-of-the-art of real-world blockchain applications using the oracle problem as a lens of analysis. Academic papers proposing real-world blockchain applications were reviewed to see if the authors considered the oracle’s role in the applications and related issues. The results found that almost 90% of the inspected literature neglected the role of oracles, thereby proposing incomplete or irreproducible projects. Through a bibliometric analysis, the third chapter sheds light on the institutions and authors that are actively contributing to the literature on oracles and promoting progress and cooperation. The study shows that, although there is still a lack of collaboration worldwide, there are dedicated authors and institutions working toward a similar and beneficial cause. The results also make it clear that most areas of oracle research are poorly addressed, with some remaining untouched. The fourth and last chapter focuses on a case study of a dairy company operating in the northeast region of Italy. The company applied blockchain technology to support the traceability of their products worldwide, and the study investigated the benefits of their innovation from the point of view of sustainability. The study also considers the role of oracle management, as it is a critical aspect of a blockchain-based project. Thus, the relationship between the company, the blockchain oracle, and the supervising authority is discussed, offering insight into how sustainable innovations can positively impact supply chain management. This work as a whole aims to shed light on blockchain oracles as an academic area of research, explaining why the study of oracles should be considered the backbone of blockchain literature development