Bitcoin Scaling with Specialization

Bitcoin on noor krüptoraha, mille populaarsus on viimaste aastatega hüppeliselt kasvanud. Praeguste trendide jätkumisel ootavad Bitcoini ees tõsised skaleerimisprobleemid. Selles uurimistöös esitame uue arhitektuuri Bitcoini-suguste krüptorahade jaoks, mis võimaldab edukalt Bitcoini skaleerida. Meie skeem toetub uut tüüpi võrgutippudele, nimelt kontrollijatele, mis kinnitavad tehinguid ja tuvastavad raha topeltkulutamist.Me esitame süsteemi, mis toetub kahendpuudele japseudojuhuarvugeneraatoritele ning võimaldab tehinguid jaotada kontrollijate vahel nii, et nende individuaalne töökoormus on väike, aga kogu süsteem saab lõpuks korralikult läbi kontrollitud.Me esitame ka mehhanisme, millega kontrollijad ja teised tipud saavad koostööd teha, et uusi blokke esitada ning kinnitada andmete usaldusväärsust.Viimasena analüüsime meie süsteemiga juurde tulevaid praktilisi kaalutlusi ja rünnakstsenaariume ning pakume viise, kuidas neid lahendada.Bitcoin is a young cryptocurrency, which has seen a rapid growth of popularity in the recent years. If the current trend continues then the scaling issues will become critical for the future use of bitcoin. In this thesis, we propose a new architecture for Bitcoin-like cryptocurrency, which efficiently facilitates Bitcoin scaling. Our scheme relies on a new type of node called validator - a node that validates transactions and detects doublespending. We propose a system based on binary trees and pseudorandom number generators that distributes the transactions among validators such that the individual workload is small but the whole system is properly validated. We also provide mechanisms for validators and other nodes to cooperate in order to add new blocks and ensure the trustworthiness of the stored data. Finally, we study practical aspects of the proposed system, analyze various attack scenarios that may occur, and propose countermeasures

Implementing Blockchain in Public Sectors in MENA Countries: Opportunities and Challenges

Governments all around the world are expanding their study and use of Blockchain technology Blockchains have the potential to improve many aspects of the public sector.  This research discusses opportunities and challenges in using blockchain in the public sectors of MENA countries.  Their public sectors may use it to safeguard sensitive documents and streamline interactions with residents and solve record-keeping challenges and improve the capabilities of the present public systems.  Instability and corruption have weakened public and market trust in MENA countries. Moreover, public data in the region is housed in a disjointed bureau and division. The process of acquiring and transferring assets, whether physical goods or financial instruments, often entails multiple transactions and a long paper trail. We argued that as blockchain needs a minimal digital trace, integrity, and immutability, it is particularly fit for the public sectors in the MENA region. A blockchain would keep detailed records of the exchanged assets as well as every step of the transaction.  All important information about each person or corporation would be maintained in a separate ledger inside an encrypted blockchain. However, the lack of expertise and experience among the government employees, and the lack of real use cases around the world are the main barriers to implementing blockchain technology in the public sector of MENA countries

PUBLIC BLOCKCHAIN SCALABILITY: ADVANCEMENTS, CHALLENGES AND THE FUTURE

In the last decade, blockchain has emerged as one of the most influential innovations in software architecture and technology. Ideally, blockchains are designed to be architecturally and politically decentralized, similar to the Internet. But recently, public and permissionless blockchains such as Bitcoin and Ethereum have faced stumbling blocks in the form of scalability. Both Bitcoin and Ethereum process fewer than 20 transactions per second, which is significantly lower than their centralized counterpart such as VISA that can process approximately 1,700 transactions per second. In realizing this hindrance in the wide range adoption of blockchains for building advanced and large scalable systems, the blockchain community has proposed first- and second-layer scaling solutions including Segregated Witness (Segwit), Sharding, and two-way pegged sidechains. Although these proposals are innovative, they still suffer from the blockchain trilemma of scalability, security, and decentralization. Moreover, at this time, little is known or discussed regarding factors related to design choices, feasibility, limitations and other issues in adopting the various first- and second-layer scaling solutions in public and permissionless blockchains. Hence, this thesis provides the first comprehensive review of the state-of-the-art first- and second-layer scaling solutions for public and permissionless blockchains, identifying current advancements and analyzing their impact from various viewpoints, highlighting their limitations and discussing possible remedies for the overall improvement of the blockchain domain

A patient agent controlled customized blockchain based framework for internet of things

Although Blockchain implementations have emerged as revolutionary technologies for various industrial applications including cryptocurrencies, they have not been widely deployed to store data streaming from sensors to remote servers in architectures known as Internet of Things. New Blockchain for the Internet of Things models promise secure solutions for eHealth, smart cities, and other applications. These models pave the way for continuous monitoring of patient’s physiological signs with wearable sensors to augment traditional medical practice without recourse to storing data with a trusted authority. However, existing Blockchain algorithms cannot accommodate the huge volumes, security, and privacy requirements of health data. In this thesis, our first contribution is an End-to-End secure eHealth architecture that introduces an intelligent Patient Centric Agent. The Patient Centric Agent executing on dedicated hardware manages the storage and access of streams of sensors generated health data, into a customized Blockchain and other less secure repositories. As IoT devices cannot host Blockchain technology due to their limited memory, power, and computational resources, the Patient Centric Agent coordinates and communicates with a private customized Blockchain on behalf of the wearable devices. While the adoption of a Patient Centric Agent offers solutions for addressing continuous monitoring of patients’ health, dealing with storage, data privacy and network security issues, the architecture is vulnerable to Denial of Services(DoS) and single point of failure attacks. To address this issue, we advance a second contribution; a decentralised eHealth system in which the Patient Centric Agent is replicated at three levels: Sensing Layer, NEAR Processing Layer and FAR Processing Layer. The functionalities of the Patient Centric Agent are customized to manage the tasks of the three levels. Simulations confirm protection of the architecture against DoS attacks. Few patients require all their health data to be stored in Blockchain repositories but instead need to select an appropriate storage medium for each chunk of data by matching their personal needs and preferences with features of candidate storage mediums. Motivated by this context, we advance third contribution; a recommendation model for health data storage that can accommodate patient preferences and make storage decisions rapidly, in real-time, even with streamed data. The mapping between health data features and characteristics of each repository is learned using machine learning. The Blockchain’s capacity to make transactions and store records without central oversight enables its application for IoT networks outside health such as underwater IoT networks where the unattended nature of the nodes threatens their security and privacy. However, underwater IoT differs from ground IoT as acoustics signals are the communication media leading to high propagation delays, high error rates exacerbated by turbulent water currents. Our fourth contribution is a customized Blockchain leveraged framework with the model of Patient-Centric Agent renamed as Smart Agent for securely monitoring underwater IoT. Finally, the smart Agent has been investigated in developing an IoT smart home or cities monitoring framework. The key algorithms underpinning to each contribution have been implemented and analysed using simulators.Doctor of Philosoph

Blockchain and Internet of Things in smart cities and drug supply management: Open issues, opportunities, and future directions

Blockchain-based drug supply management (DSM) requires powerful security and privacy procedures for high-level authentication, interoperability, and medical record sharing. Researchers have shown a surprising interest in Internet of Things (IoT)-based smart cities in recent years. By providing a variety of intelligent applications, such as intelligent transportation, industry 4.0, and smart financing, smart cities (SC) can improve the quality of life for their residents. Blockchain technology (BCT) can allow SC to offer a higher standard of security by keeping track of transactions in an immutable, secure, decentralized, and transparent distributed ledger. The goal of this study is to systematically explore the current state of research surrounding cutting-edge technologies, particularly the deployment of BCT and the IoT in DSM and SC. In this study, the defined keywords “blockchain”, “IoT”, drug supply management”, “healthcare”, and “smart cities” as well as their variations were used to conduct a systematic search of all relevant research articles that were collected from several databases such as Science Direct, JStor, Taylor & Francis, Sage, Emerald insight, IEEE, INFORMS, MDPI, ACM, Web of Science, and Google Scholar. The final collection of papers on the use of BCT and IoT in DSM and SC is organized into three categories. The first category contains articles about the development and design of DSM and SC applications that incorporate BCT and IoT, such as new architecture, system designs, frameworks, models, and algorithms. Studies that investigated the use of BCT and IoT in the DSM and SC make up the second category of research. The third category is comprised of review articles regarding the incorporation of BCT and IoT into DSM and SC-based applications. Furthermore, this paper identifies various motives for using BCT and IoT in DSM and SC, as well as open problems and makes recommendations. The current study contributes to the existing body of knowledge by offering a complete review of potential alternatives and finding areas where further research is needed. As a consequence of this, researchers are presented with intriguing potential to further create decentralized DSM and SC apps as a result of a comprehensive discussion of the relevance of BCT and its implementation.© 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Navigating the IoT landscape: Unraveling forensics, security issues, applications, research challenges, and future

Given the exponential expansion of the internet, the possibilities of security attacks and cybercrimes have increased accordingly. However, poorly implemented security mechanisms in the Internet of Things (IoT) devices make them susceptible to cyberattacks, which can directly affect users. IoT forensics is thus needed for investigating and mitigating such attacks. While many works have examined IoT applications and challenges, only a few have focused on both the forensic and security issues in IoT. Therefore, this paper reviews forensic and security issues associated with IoT in different fields. Future prospects and challenges in IoT research and development are also highlighted. As demonstrated in the literature, most IoT devices are vulnerable to attacks due to a lack of standardized security measures. Unauthorized users could get access, compromise data, and even benefit from control of critical infrastructure. To fulfil the security-conscious needs of consumers, IoT can be used to develop a smart home system by designing a FLIP-based system that is highly scalable and adaptable. Utilizing a blockchain-based authentication mechanism with a multi-chain structure can provide additional security protection between different trust domains. Deep learning can be utilized to develop a network forensics framework with a high-performing system for detecting and tracking cyberattack incidents. Moreover, researchers should consider limiting the amount of data created and delivered when using big data to develop IoT-based smart systems. The findings of this review will stimulate academics to seek potential solutions for the identified issues, thereby advancing the IoT field.Comment: 77 pages, 5 figures, 5 table

Modern computing: Vision and challenges

Over the past six decades, the computing systems field has experienced significant transformations, profoundly impacting society with transformational developments, such as the Internet and the commodification of computing. Underpinned by technological advancements, computer systems, far from being static, have been continuously evolving and adapting to cover multifaceted societal niches. This has led to new paradigms such as cloud, fog, edge computing, and the Internet of Things (IoT), which offer fresh economic and creative opportunities. Nevertheless, this rapid change poses complex research challenges, especially in maximizing potential and enhancing functionality. As such, to maintain an economical level of performance that meets ever-tighter requirements, one must understand the drivers of new model emergence and expansion, and how contemporary challenges differ from past ones. To that end, this article investigates and assesses the factors influencing the evolution of computing systems, covering established systems and architectures as well as newer developments, such as serverless computing, quantum computing, and on-device AI on edge devices. Trends emerge when one traces technological trajectory, which includes the rapid obsolescence of frameworks due to business and technical constraints, a move towards specialized systems and models, and varying approaches to centralized and decentralized control. This comprehensive review of modern computing systems looks ahead to the future of research in the field, highlighting key challenges and emerging trends, and underscoring their importance in cost-effectively driving technological progress

Blockchain in Education

This report introduces the fundamental principles of the Blockchain focusing on its potential for the education sector. It explains how this technology may both disrupt institutional norms and empower learners. It proposes eight scenarios for the application of the Blockchain in an education context, based on the current state of technology development and deployment.JRC.B.4-Human Capital and Employmen

Role of Blockchain Technology in Combating COVID‐19 Crisis

Abstract: Please refer to full text to view abstrac