Xiao Fan Liu, Xin-Jian Jiang, Si-Hao Liu, Chi K. Tse
Cryptocurrencies gain trust in users by publicly disclosing the full creation and transaction history. In return, the transaction history faithfully records the whole spectrum of cryptocurrency user behaviors. This article analyzes and summarizes the existing research on knowledge discovery in the cryptocurrency transactions using data mining techniques. Specifically, we classify the existing research into three aspects, i.e., transaction tracings and blockchain address linking, the analyses of collective user behaviors, and the study of individual user behaviors. For each aspect, we present the problems, summarize the methodologies, and discuss major findings in the literature. Furthermore, an enumeration of transaction data parsing and visualization tools and services is also provided. Finally, we outline several future directions in this research area, such as the current rapid development of Decentralized Finance (De-Fi) and digital fiat money.
Anton Hasselgren, Paul Kengfai Wan, Margareth Horn, Katina Kralevska · 5 authors
The transparent and decentralized characteristics associated with blockchain can be both appealing and problematic when applied to a healthcare use-case. As health data is highly sensitive, it is therefore, highly regulated to ensure the privacy of patients. At the same time, access to health data and interoperability are in high demand. Regulatory frameworks such as GDPR and HIPAA are, amongst other objectives, meant to contribute to mitigating the risk of privacy violations of health data. Blockchain features can likely improve interoperability and access control to health data, and at the same time, preserve or even increase, the privacy of patients. Blockchain applications should address compliance with the current regulatory framework to increase real-world feasibility. This exploratory work indicates that published proof-of-concepts in the healthcare domain comply with GDPR, to an extent. Blockchain developers need to make design choices to be compliant with GDPR since currently, none available blockchain platform can show compliance out of the box.
Ashish Rajendra Sai, Jim Buckley, Brian Fitzgerald, Andrew Le Gear
Bitcoin introduced delegation of control over a monetary system from a select few to all who participate in that system. This delegation is known as the decentralization of controlling power and is a powerful security mechanism for the ecosystem. After the introduction of Bitcoin, the field of cryptocurrency has seen widespread attention from industry and academia, so much so that the original novel contribution of Bitcoin, i.e., decentralization, may be overlooked, due to decentralizations’ assumed fundamental existence for the functioning of such crypto-assets. However, recent studies have observed a trend of increased centralization in cryptocurrencies such as Bitcoin and Ethereum. As this increased centralization has an impact the security of the blockchain, it is crucial that it is measured, towards adequate control. This research derives an initial taxonomy of centralization present in decentralized blockchains through rigorous synthesis using a systematic literature review. This is followed by iterative refinement through expert interviews. We systematically analyzed 89 research papers published between 2009 and 2019. Our study contributes to the existing body of knowledge by highlighting the multiple definitions and measurements of centralization in the literature. We identify different aspects of centralization and propose an encompassing taxonomy of centralization concerns. This taxonomy is based on empirically observable and measurable characteristics. It consists of 13 aspects of centralization, classified over six architectural layers: Governance, Network, Consensus, Incentive, Operational, and Application. We also discuss how the implications of centralization can vary depending on the aspects studied. We believe that this review and taxonomy provides a comprehensive overview of centralization in decentralized blockchains involving various conceptualizations and measures.
Ismaeel Al Ridhawi, Moayad Aloqaily, Yaser Jararweh
The rise of fast communication media both at the core and at the edge has resulted in unprecedented numbers of sophisticated and intelligent wireless IoT devices. Tactile Internet has enabled the interaction between humans and machines within their environment to achieve revolutionized solutions both on the move and in real-time. Many applications such as intelligent autonomous self-driving, smart agriculture and industrial solutions, and self-learning multimedia content filtering and sharing have become attainable through cooperative, distributed and decentralized systems, namely, volunteer computing. This article introduces a blockchain-enabled resource sharing and service composition solution through volunteer computing. Device resource, computing, and intelligence capabilities are advertised in the environment to be made discoverable and available for sharing with the aid of blockchain technology. Incentives in the form of on-demand service availability are given to resource and service providers to ensure fair and balanced cooperative resource usage. Blockchains are formed whenever a service request is initiated with the aid of fog and mobile edge computing (MEC) devices to ensure secure communication and service delivery for the participants. Using both volunteer computing techniques and tactile internet architectures, we devise a fast and reliable service provisioning framework that relies on a reinforcement learning technique. Simulation results show that the proposed solution can achieve high reward distribution, increased number of blockchain formations, reduced delays, and balanced resource usage among participants, under the premise of high IoT device availability.
Saqib Hakak, Wazir Zada Khan, Gulshan Amin Gilkar, Basem Assiri · 7 authors
The rise of blockchain technology within a few years has attracted researchers across the world. The prime reason for worldwide attention is undoubtedly due to its feature of immutability along with the decentralized approach of data protection. As this technology is progressing, lots of developments in terms of identifying new applications, blockchain-based platforms, consensus mechanisms, etc are taking place. Hence, in this article, an attempt has been made to review the recent advancements in blockchain technology. Furthermore, we have also explored the available blockchain platforms, highlighted and explored future research directions and challenges.
Yulei Wu, Hong‐Ning Dai, Hao Wang, Kim‐Kwang Raymond Choo
5G-enabled drones have potential applications in a variety of both military and civilian settings (e.g., monitoring and tracking of individuals in demonstrations and/or enforcing of social / physical distancing during pandemics such as COVID-19). Such applications generally involve the collection and dissemination of (massive) data from the drones to remote data centres for storage and analysis, for example via 5G networks. Consequently, there are security and privacy considerations underpinning 5G-enabled drone communications. We posit the potential of leveraging blockchain to facilitate privacy preservation, and therefore in this article we will review existing blockchain-based solutions after introducing the architecture for 5G-enabled drone communications and blockchain. We will also review existing legislation and data privacy regulations that need to be considered in the design of blockchain-based solutions, as well as identifying potential challenges and open issues which will hopefully inform future research agenda.
Juan C. Olivares-Rojas, Enrique Reyes-Archundia, José A. Gutiérrez-Gnecchi, Ismael Molina-Moreno
Electricity is an essential comfort to support our daily activities. With the competitive increase and energy costs by the industry, new values and opportunities for delivering electricity to customers are produced. One of these new opportunities is electric vehicles. With the arrival of electric vehicles, various challenges and opportunities are being presented in the electric power system worldwide. For example, under the traditional electric power billing scheme, electric power has to be consumed where it is needed so that end-users could not charge their electric vehicles at different points (e.g. a relative's house) if this the correct user is not billed (this due to the high consumption of electrical energy that makes it expensive). To achieve electric mobility, they must solve new challenges, such as the smart metering of energy consumption and the cybersecurity of these measurements. The present work shows a study of the different smart metering technologies that use blockchain and other security mechanisms to achieve e-mobility.
Many blockchain-based cryptocurrencies provide users with online blockchain explorers for viewing online transaction data. However, traditional blockchain explorers mostly present transaction information in textual and tabular forms. Such forms make understanding cryptocurrency transaction mechanisms difficult for novice users (NUsers). They are also insufficiently informative for experienced users (EUsers) to recognize advanced transaction information. This study introduces a new online cryptocurrency transaction data viewing tool called SilkViser. Guided by detailed scenario and requirement analyses, we create a series of appreciating visualization designs, such as paper ledger-inspired block and blockchain visualizations and ancient copper coin-inspired transaction visualizations, to help users understand cryptocurrency transaction mechanisms and recognize advanced transaction information. We also provide a set of lightweight interactions to facilitate easy and free data exploration. Moreover, a controlled user study is conducted to quantitatively evaluate the usability and effectiveness of SilkViser. Results indicate that SilkViser can satisfy the requirements of NUsers and EUsers. Our visualization designs can compensate for the inexperience of NUsers in data viewing and attract potential users to participate in cryptocurrency transactions.
We are experiencing an unprecedented healthcare crisis caused by newly discovered coronavirus disease (COVID-19). The outbreaks of COVID-19 reveal the frailties of existing healthcare systems. Therefore, the digital transformation of healthcare systems becomes an inevitable trend. During this process, the Internet of Medical Things (IoMT) plays a crucial role, while intrinsic vulnerabilities of security and privacy deter the wide adoption of IoMT. In this article, we present a blockchain-enabled IoMT to address the security and privacy concerns of IoMT systems. We also discuss the solutions brought by blockchain-enabled IoMT to COVID-19 from five different perspectives. Moreover, we outline the open challenges and future directions of blockchain-enabled IoMT.
Amir Hussain Zolfaghari, Herbert Daly, Mahdi Nasiri, Roxana Sharifian
Blockchain technology has rapidly evolved from an enabling technology for cryptocurrencies to a potential solution to a wider range of problems found in data-centric and distributed systems. Interest in this area has encouraged many recent innovations to address challenges that traditional approaches of design have been unable to meet. Healthcare Information Systems with issues around privacy, interoperability, data integrity, and access control is potentially an area where blockchain technology may have a significant impact. Blockchain, however, is a meta-technology, combining multiple techniques, as it is often important to determine how best to separate concerns in the design and implementation of such systems. This paper proposes a layered approach for the organization of blockchain in healthcare applications. Key issues driving the adoption of this technology are explored. A model presenting the points in each layer is explored. Finally, we present an example of how the perspective we describe can improve the development of Health Information Systems.
Sarang Chaudhari, Michael Clear, Philip Bradish, Hitesh Tewari
Uniquely identifying individuals across the various networks they interact with on a daily basis remains a challenge for the digital world that we live in, and therefore the development of secure and efficient privacy preserving identity mechanisms has become an important field of research. In addition, the popularity of decentralised decision making networks such as Bitcoin has seen a huge interest in making use of distributed ledger technology to store and securely disseminate end user identity credentials. In this paper we describe a mechanism that allows one to store the COVID-19 vaccination details of individuals on a publicly readable, decentralised, immutable blockchain, and makes use of a two-factor authentication system that employs biometric cryptographic hashing techniques to generate a unique identifier for each user. Our main contribution is the employment of a provably secure input-hiding, locality-sensitive hashing algorithm over an iris extraction technique, that can be used to authenticate users and anonymously locate vaccination records on the blockchain, without leaking any personally identifiable information to the blockchain.
Blockchain is often presented as a technological development; however, clearly it is not only that: the `Blockchain buzz' exists in the context of current social and political developments. In this essay, we analyse blockchain technology and its social and political context from a perspective of Marxist economic theory. Since arguably the last great inflection point in society and technology was analysed by Marx in terms of labour and capital and since we seem to be experiencing a shift in the balance between these forces today, it makes sense to revisit the Marxist ideas and apply them to the current situation, to see how well they still apply and if necessary to update them for current events.
Algocracy is the rule by algorithms. This paper summarises technologies useful to create algocratic social machines and presents idealistic examples of their application. In particular, it describes smart contracts and their implementations, challenges of behaviour mining and prediction, as well as game-theoretic and AI approaches to mechanism design. The presented idealistic examples of new algocratic solutions are picked from the reality of a modern state. The examples are science funding, trade by organisations, regulation of rental agreements, ranking of significance and sortition. Artificial General Intelligence is not in the scope of this feasibility study.
Kevin Wallis, Jan Stodt, Eugen Jastremskoj, Christoph Reich
The digital transformation of companies is expected to increase the digital interconnection between different companies to develop optimized, customized, hybrid business models. These cross-company business models require secure, reliable, and traceable logging and monitoring of contractually agreed information sharing between machine tools, operators, and service providers. This paper discusses how the major requirements for building hybrid business models can be tackled by the blockchain for building a chain of trust and smart contracts for digitized contracts. A machine maintenance use case is used to discuss the readiness of smart contracts for the automation of workflows defined in contracts. Furthermore, it is shown that the number of failures is significantly improved by using these contracts and a blockchain.
With the advancement of the smart grid, the current energy system is moving towards a future where people can buy what they need, sell when they have excess, and can trade the right of buying to other prosumers. While the first two schemes already exist in the market, selling the right of buying, also known as negawatt trading, is something that is yet to be implemented. Here, we review the challenges and prospects of negawatt trading in light of recent technological advancements. Through reviewing a number of emerging technologies, we show that the necessary methodologies that are needed to establish negawatt trading as a feasible energy management scheme in the smart grid are already available. Grid interactive buildings and distributed ledger technologies for instance can ensure active participation and fair pricing. However, some additional challenges need to address for fully functional negawatt trading mechanisms in today's energy market.
Laavanya Rachakonda, Anand K. Bapatla, Saraju P. Mohanty, Elias Kougianos
Considering today's lifestyle, people just sleep forgetting the benefits it provides to the human body. The reasons for not having a productive sleep could be many. Smart-Yoga Pillow (SaYoPillow) is envisioned as a device that may help in recognizing the importance of a good quality sleep to alleviate stress while establishing a measurable relationship between stress and sleeping habits. A system that analyzes the sleeping habits by continuously monitoring the physiological changes that occur during rapid eye movement (REM) and non-rapid eye movement (NREM) stages of sleep is proposed in the current work. In addition to the physiological parameter changes, factors such as sleep duration, snoring range, eye movement, and limb movements are also monitored. The SaYoPillow system is processed at the edge level with the storage being at the cloud. Not having to compromise the user's privacy, SaYoPillow proposes secure data transmission for both uploading and retrieving, and secure storage and communications as an attempt to reduce malicious attacks on healthcare. A user interface is provided for the user to control data accessibility and visibility. SaYoPillow has 96% accuracy which is close to other existing research works. However, SaYoPillow is the only work with security features as well as only work that considers sleeping habits for stress.
Water and other resources are becoming scarcer every day, and developing countries are the neediest for an immediate intervention. Water, as a national need, is considered to be one of the main causes for conflicts in the 21st century. Peer-to-peer trading is one of the most convenient, scalable and sustainable solutions but faces organization challenges such as: the absence of suitable business models motivating normal users to sell their generated resources, currency and financial settlement complexities, and single utility markets. We propose a multi-utility trading platform, based on blockchain technology which can address the challenges faced by peer-to-peer trading. This platform meets the needs of developing countries in particular as well as rural areas of developed countries. The open nature of our proposed design makes it suitable for adoption and use by various stakeholders.
We describe a simple approach to peer-to-peer electronic mail that would allow users of ordinary workstations and mobile devices to exchange messages without relying upon third-party mail server operators. Crucially, the system allows participants to establish and use multiple unlinked identities for communication with each other. The architecture leverages ordinary SMTP for message delivery and Tor for peer-to-peer communication. The design offers a robust, unintrusive method to use self-certifying Tor onion service names to bootstrap a web of trust based on public keys for end-to-end authentication and encryption, which in turn can be used to facilitate message delivery when the sender and recipient are not online simultaneously. We show how the system can interoperate with existing email systems and paradigms, allowing users to hold messages that others can retrieve via IMAP or to operate as a relay between system participants and external email users. Finally, we show how it is possible to use a broadcast protocol to implement mailing lists and how distributed ledger technology might be used to bootstrap consensus about shared knowledge among list members.
To draw a roadmap of current research activities of the blockchain community, we first conduct a brief overview of state-of-the-art blockchain surveys published in the recent 5 years. We found that those surveys are basically studying the blockchain-based applications, such as blockchain-assisted Internet of Things (IoT), business applications, security-enabled solutions, and many other applications in diverse fields. However, we think that a comprehensive survey towards the essentials of blockchains by exploiting the state-of-the-art theoretical modelings, analytic models, and useful experiment tools is still missing. To fill this gap, we perform a thorough survey by identifying and classifying the most recent high-quality research outputs that are closely related to the theoretical findings and essential mechanisms of blockchain systems and networks. Several promising open issues are also summarized finally for future research directions. We wish this survey can serve as a useful guideline for researchers, engineers, and educators about the cutting-edge development of blockchains in the perspectives of theories, modelings, and tools.
A trusted achievement record is a secure system that aims to record and authenticate certificates as well as key learning activities and achievements. This paper intends to gather important information on the thoughts and outlooks of stakeholders on an achievement record system that uses blockchain and smart contract technology. The system would allow stakeholders (for example employers) to validate learning records. Two main aims are investigated. The first is to evaluate the suitability of the idea of building a trusted achievement record for learners in higher education, and to evaluate potential user knowledge of blockchain technology. This is to ensure that a designed system is usable. The second aim includes an interview conducted with a small group of participants to gather information about the challenges individuals have when creating, and reviewing CVs. Overall, 90% of participants agreed that there was a strong need for a trusted achievement record. In addition, 93.64% of respondents stated that they felt it was invaluable to have a system that is usable by all stakeholders. When tackling the second aim it was found that a primary challenge is lack of knowledge of blockchain and its complexity. From the employers' perspective, there is a lack of trust due to inaccuracies when students describe skills and qualifications in their resumes.
The primary purpose of this paper is to provide a design of a blockchain-based system, which produces a verifiable record of achievements. Such a system has a wide range of potential benefits for students, employers and higher education institutions. A verifiable record of achievements enables students to present academic accomplishments to employers, within a trusted framework. Furthermore, the availability of such a record system would enable students to review their learning throughout their career, giving them a platform on which to plan for their future accomplishments, both individually and with support from other parties (for example, academic advisors, supervisors, or potential employers). The proposed system will help students in universities to increase their extra-curricular activities and improve non-academic skills. Moreover, the system will facilitate communication between industry, students, and universities for employment purposes and simplify the search for the most appropriate potential employees for the job.
Role-based access control (RBAC) policies represent the rights of subjects in terms of roles to access resources. This research proposes a scalable, flexible and auditable RBAC system using the EOS blockchain platform to meet the security requirements of organizations. The EOS blockchain platform for developing smart contract and decentralized applications (DAPPs) aims to address the scalability problem found in existing blockchain platforms. This smart contract platform aims to eliminate transaction fees while conducting millions of transactions per second. In our proposed approach, the EOS blockchain transparently stores RBAC policies. Administrative roles control access to resources at a higher level according to the way organisations perform operations. An organisation creates roles, role hierarchies and constraints to regulate user actions. Therefore, once an RBAC framework is established, the administrative user (issuer) only needs to grant and revoke roles to support changes in the organisational structure. Our proposed blockchain-based RBAC supports delegation capabilities using gaseless transactions which makes it adoptable and appealing in a large number of application scenarios. Our proposed solution is application-agnostic and well-suited for diverse use cases. Existing state-of-the art security frameworks are not suitable due to the difficulty of scale, higher cost and single point of failure. Consequently, organisations demand a scalable, cost-effective and lightweight access control solution which can better protect their privacy as well. A proof of concept implementation is developed based on the EOS blockchain. Our experimental results and analysis clearly show that our EOS blockchain-based RBAC outperforms existing blockchain platforms in terms of cost, latency, block generation time, contract execution time and throughput.
Open technologies, decentralized computation and intelligent applications enable the third-generation web, Web 3.0, thereby digitizing whole industries. The emerging Economy of Things (EoT) will be based on software agents running on peer-to-peer trustless networks that require a programmable, regulation conform means of payment. We give an overview of current solutions that differ in their fundamental values and technological possibilities, like e.g. private-issued stablecoins, DLT-issued electronic money and genuine cryptocurrencies. Based on this analysis, we present the concept of justified trust and propose to combine the strengths of the crypto based, decentralized trustless elements with established and well regulated means of payment, based on this concept, via a secure external re-balancing interface. Combining the advantages, e.g. lightweight, trustless, efficient high frequency micro state transfers on the one hand, and ease of use, widely spread, accepted alignment to a multitude of regulative requirements, on the other hand, while neither leading into a lock-in in any of the proposed solutions, nor undermining the basic principles of the crypto-movement or unnecessarily reinforcing the banking system provides a synergy and the necessary flexibility for further evolution alongside the regulative framework. This offers a regulation conform transitional solution that can be implemented in the short term, which enables companies to place their decentralized business operations in a regulated environment. The contribution of our work is twofold: First, we illustrate and discuss different DLT-operable means of payment. Second, our research proposes a novel hybrid payment solution by interfacing trustless with justified trust combined generalized state channels.
Will Abramson, Nicole E. van Deursen, William J Buchanan
A substantial administrative burden is placed on healthcare professionals as they manage and progress through their careers. Identity verification, pre-employment screening and appraisals: the bureaucracy associated with each of these processes takes precious time out of a healthcare professional's day. Time that could have been spent focused on patient care. In the midst of the COVID-19 crisis, it is more important than ever to optimize these professionals' time. This paper presents the synthesis of a design workshop held at the Royal College of Physicians of Edinburgh (RCPE) and subsequent interviews with healthcare professionals. The main research question posed is whether these processes can be re-imagined using digital technologies, specifically Self-Sovereign Identity? A key contribution in the paper is the development of a set of user-led requirements and design principles for identity systems used within healthcare. These are then contrasted with the design principles found in the literature. The results of this study confirm the need and potential of professionalising identity and credential management throughout a healthcare professional's career.