Blockchain technology is an emerging distributed ledger technology that has exploratory applications in many areas. The consensus algorithm, as the core module of the blockchain, has an important impact on the security, scalability, and efficiency of the blockchain network. The consensus algorithm is also a popular topic in current blockchain technology research. In existing consortium blockchains and public blockchains, the blockchain has low efficiency or poor fault tolerance because of the limitations of the consensus algorithm. To both ensure the fault tolerance of the blockchain and improve the scalability and throughput, in this paper, we propose a new type of consensus algorithm: mixed Byzantine fault tolerance (MBFT). MBFT uses sharding and layered technology. MBFT functionally partitions the nodes that participate in the consensus process and improves the scalability and efficiency without sacrificing security. MBFT also introduces a random node selection mechanism and a credit mechanism to improve security and fault tolerance. We analyze the security and experiment on transaction throughput in a real network environment. The results prove that MBFT has good security and scalability and high throughput.
Additive Manufacturing (AM) is a major advancement in the digitization of manufacturing and production operations. Additive manufacturing uses three dimensional digital design, software and hardware equipment to precisely deposit layered materials for on-demand product manufacturing. The distinct advantages in enabling additive manufacturing includes cost efficiency, reduced time-to-market, flexibility and precise customization. However, several challenges such as trusted traceability, certification for quality compliance, and protecting intellectual property need to be addressed. Blockchain-based distributed ledgers provide tremendous advantages for product traceability and ensure trust among participating stakeholders. In this paper, we propose a blockchain-based solution for product traceability produced using additive manufacturing, guaranteeing secure and trusted traceability, accessibility, and immutability of transactions, and data provenance among supply chain stakeholders. Our proposed solution utilizes Ethereum smart contracts to govern and trace transactions initiated by participants involved in the manufacturing process. Decentralized storage of Inter-Planetary File Systems is used to store and share design files, IoT device records, and additional product specifications. We provide the system architecture, implementation, and detailed algorithms that demonstrate the working principles of our proposed solution for secure AM. Furthermore, we present detailed security and cost analysis of the solution highlighting its efficiency with respect to key security and performance requirements.
Distributed ledgers and blockchain technologies can improve system security and trustworthiness by providing immutable replicated histories of data. Blockchain is a linked list of blocks containing digitally signed transactions, a cryptographic hash of the previous block, and a timestamp stored in a decentralized and distributed network. The Internet of Things (IoT) is one of the application domains in which security based on blockchain is discussed. In this article, we review the structure and architectures of distributed IoT systems and explain the motivations, challenges, and needs of blockchain to secure such systems. However, there are substantial threats and attacks to blockchain that must be understood, as well as suitable approaches to mitigate them. We, therefore, survey the most common attacks to blockchain systems and the solutions to mitigate them, with the objective of assessing how malicious these attacks are in the IoT context.
Die Möglichkeit, Computerberechnungen mit einem Beweis für deren korrekte Ausführung zu hinterlegen, scheint in Zeiten der oft genannten ‘Digitalisierung’ ein vielversprechendes Mittel zu sein, um es Parteien, die einander nicht trauen, zu ermöglichen sich auszutauschen. Diese Korrektheitsbeweise sind gerade im Themengebiet der Blockchain interessante und vielversprechende Kandidaten, um dortige Probleme zu adressieren. In dieser Arbeit untersuchen wir formal, was eine Blockchain im Sinne Nakamotos auszeichnet, und inwiefern sogenannte ‘Privacy Enhancing Technolgies’ in diesen dezentralen Systemen Anwendung finden. Das Hauptaugenmerk legen wir dabei auf ‘pairing-based preprocessed zero knowledge succinct non interactive arguments of knowledge’ (zkSNARKs). Wir untersuchen deren mathematische Grundlage und entwickeln unsere eigene zkSNARK Konstruktion. Diese basiert auf einer Erweiterung der gängigen F-arithmetischen Schaltung, die neben arithmetischen Operationen auch die der skalare Gruppenexponentiation auf elliptischen Kurven unterstützt. Die Implementierung ist in der Sprache Golang verfasst und unter einer GPL3.0 Lizenz auf Github zugänglich gemacht. Das Programm übersetzt eine eigens dafür entwickelte Programmiersprache in die Form eines ‘QuadraticArithmetic Programs’ und kann daher über unsere Arbeit hinaus in Beweissystemen basierend auf F-arithmetischen Schaltungen eingesetzt werden.
Abstract This paper elaborates on the blockchain-based identity authentication and intelligent credit reporting method. The technologies of multidimensional authentication, multifactor weighted score calculation, security threshold, distributed ledger, smart contract and encryption algorithm are proposed to realize dynamic identity security authentication and intelligent risk control. The user behaviour analysis system, real-time risk identification system and intelligent risk prevention system are constructed. The multidimensional credit data collection is realized through blockchain distributed nodes. The distributed ledger of credit reporting, intelligent pricing of assets and automatic credit rating of users are proposed. It realizes credit reporting system and service based on multidimensional data, distributed ledgers, and smart contracts.
Task: to develop a concept for implementing distributed Ledger technologies (blockchain) in passenger railway transport and to justify the approach to evaluating the effectiveness of these technologies. Methods: content analysis of special industry research, analysis of specialized statistical reporting on the use of digital systems and technologies, survey, mathematical modeling, and others. Result. The author analyzes the trends of the multimodal passenger transport market, in particular the European segment. It is established that due to the significant development of multimodality in passenger transport, transport organizations will be able to meet modern customer requests mainly when switching to network technologies, mainly to digital systems of distributed transaction data registry. The concept of passenger blockchain in transport is proposed: its functionality, platform composition, digital modules, additional services for passengers. The effects resulting from the introduction of blockchain in passenger transportation are systematized, the sources of their occurrence, and their quantitative assessment for the passenger railway complex of Russia is given. Practical significance: the results of the study deepen methodological developments in the field of economic evaluation of investment projects for the introduction of digitalization technologies. They are in demand by managers of transport companies, development specialists, and analysts who evaluate digital technologies.
D.S. Popović, C. Avis, M. Byrne, Chong-Soo Cheung · 10 authors
Abstract Insurance industry practitioners have deep knowledge of their industry, but there is a lack of a simple-to-understand, practical blueprint on applying distributed ledger technology solutions, including blockchain. This paper provides a practical guide for actuaries, risk professionals, insurance companies and their Boards on blockchain, including an education piece to provide an understanding of the technology. Examples of real-world applications and use cases in insurance are provided to illustrate the capability of the technology. The current risks and challenges in adopting the technology are also considered. Finally, a checklist of issues to consider in adopting a blockchain solution for insurance business problems is provided.
Natalia Dashkevich, Steve Counsell, Giuseppe Destefanis
Blockchain is a novel technology capturing the attention of Central Banks and a technology with significant disruptive potential. However, a gap in research effort between practitioners and academics seems to have emerged. This paper analyses and maps that gap by exploring trends in peer-reviewed research contributions through thematic categorisation of academic literature on Distributed Ledger Technology (DLT) use-cases for services, operations and functions performed by central banks. Furthermore, this paper provides summaries of opportunities and challenges for central banks arising from blockchain adaptation to each of those use-cases. To achieve this goal, we utilise a Systematic Mapping Study approach. The paper presents an in-depth assessment of statistical and thematic analysis of research maturity and the types of researchers, with specific emphasis on types of central bank use-cases considered for blockchain adaptation. Our work contributes to an understanding of where the most or least attention is directed, allowing for identification of gaps and opportunities for both academics, practitioners and combinations of each. Results show that the research topic is a comparatively new domain. It confirms the gap between depth and volume of the research provision from industry and academia, with industry leading the trend. Our study also found that the most research-intensive use-cases are those for: 1) Central Bank issued Digital Currency (CBDC), 2) Regulatory Compliance and 3) Payment Clearing and Settlement Systems (PCS) operated by central banks; a comparatively low engagement was found in the areas of 4) Assets Transfer/Ownership and 5) Audit Trail.
Samrah Arif, M. Arif Khan, Sabih ur Rehman, Muhammad Ashad Kabir · 5 authors
Smart Home automation is increasingly gaining popularity among current applications of Internet of Things (IoT) due to the convenience and facilities it provides to the home owners. Sensors are employed within the home appliances via wireless connectivity to be accessible remotely by home owners to operate these devices. With the exponential increase of smart home IoT devices in the marketplace such as door locks, light bulbs, power switches etc, numerous security concerns are arising due to limited storage and processing power of such devices, making these devices vulnerable to several attacks. Due to this reason, security implementations in the deployment of these devices has gained popularity among researchers as a critical research area. Moreover, the adoption of traditional security schemes has failed to address the unique security concerns associated with these devices. Blockchain, a decentralised database based on cryptographic techniques, is gaining enormous attention to assure security of IoT systems. The blockchain framework within an IoT system is a fascinating substitute to the traditional centralised models, which has some significant concerns in fulfilling the demand of smart homes security. In this article, we aim to examine the security of smart homes by instigating the adoption of blockchain and exploring some of the currently proposed smart home architectures using blockchain technology. To present our findings, we describe a simple secure smart home framework based on a refined version of blockchain called Consortium blockchain. We highlight the limitations and opportunities of adopting such an architecture. We further evaluate our model and conclude with the results by designing an experimental testbed using a few household IoT devices commonly available in the marketplace.
Jun Wu, Mianxiong Dong, Kaoru Ota, Jianhua Li · 5 authors
Currently, IoT has become an important carrier of blockchains, which not only makes blockchain more ubiquitous but also improves the security of IoT. Consensus is the core component of blockchains with various forms, which raises the following challenges. Dynamic management and configuration of the consensuses in a blockchain are required because IoT applications have high dynamics. Moreover, an IoT node is usually reutilized by various applications in different blockchains, which means the IoT node should be switched frequently to cross consensuses in different blockchains. To address this, a software-defined blockchain architecture is proposed to realized the dynamic configurations for blockchains. Then a consensus function virtualization approach with application-aware work flow is proposed, which can abstract and manage various consensus resources. Next, a transfer-learning-based intelligent scheme is designed to implement the application- layer packet analysis and perform the efficient management of virtualized consensus resources. Experiment results indicate the feasibility of the proposed scheme. This work is significant in enhancing the flexibility and extendibility of blockchains in IoT.
Blockchain can be viewed as a public ledger maintained collectively by a large number of participators based on consensus protocol. We are interested in how di erent consensus protocols and trade network topologies a ect the performance of a blockchain system, which has not been studied in the literature yet. In this paper, we proposed an agent-based model consisting of multiple trader and miner agents, and one system agent. We investigated three consensus protocols, namely proof-of-work (PoW), proof-of-stake (PoS), and delegated proof-of-stake (DPoS). We also examined three common trade network topologies: random, small-world, and scale-free. We find that both consensus protocol and trade network topology can impact the performance of blockchain system. PoS and DPoS are generally better than PoW in terms of increasing trade e iciency and equalizing wealth. Besides, scale-free trade network is not favorable because its trade e iciency is quite low, which moderates the price fluctuation and wealth inequality. Since connectivity inequality determines trade e iciency and wealth inequality, it is crucial to increase the connectivity among participants by means of not only using better consensus protocols such as PoS or DPoS, but also incentivizing apathetic or newly-joined participants to link with others. We suggest that our findings could be useful to the designers, practitioner and researchers of blockchain system and token economy.
Denna studie undersöker huruvida avsiktligt implementerad friktion inom interaktionsdesign kan minska antal användarfel vid insatsprocessen för blockkedjor med Proof-of-Stake teknik. Friktion som avsiktligt implementerats har tidigare visats kunna leda till färre användarfel. Det spekuleras i att blockkedjor kan komma att användas i större utsträckning i framtiden. Eftersom fel i insatsprocessen för en blockkedja med Proof-of-Stake teknik kan leda till att pengar går förlorade valdes det området för att undersökas närmare om friktion kan leda till färre användarfel. Studien avgränsas till en typ av avsiktlig friktion som kallas design for pauses som syftar till att få användaren att tillfälligt stanna upp med sin interaktion. I studien skapades två versioner av en prototyp på en insatsprocess till blockkedjan Ethereum som testades på två olika testgrupper. Ena versionen av prototypen innehöll avsiktligt implementerad friktion och i den andra versionen adderades ingen friktion avsiktligt. Deltagarna i testet ombads utföra insatsprocessen i prototypen där deras interaktioner granskades och statistik fördes på antal användarfel. Användarfelen delades upp i två kategorier: slarvfel och misstag. Resultaten från testerna visar på att avsiktlig friktion av typen design for pauses minskar antal användarfel av typen misstag. Ytterligare forskning krävs för att besvara om design for pauses kan bidra till att minska antal användarfel av typen slarvfel.
Designed for commercial decentralized applications (DApps), EOSIO is a Delegated Proof-of-Stake (DPoS) based blockchain system. It has overcome some shortages of the traditional blockchain systems like Bitcoin and Ethereum with its outstanding features (e.g., free for usage, high throughput and eco-friendly), and thus becomes one of the mainstream blockchain systems. Though there exist billions of transactions in EOSIO, the ecosystem of EOSIO is still relatively unexplored. To fill this gap, we conduct a systematic graph analysis on the early EOSIO by investigating its four major activities, namely account creation, account vote, money transfer and contract authorization. We obtain some novel observations via graph metric analysis, and our results reveal some abnormal phenomenons like voting gangs and sham transactions.
Introduction. The initiated processes of administrative and financial decentralization in Ukraine have actualized the issues of modernization of the social sphere in general and its key segments, among which education occupies a prominent place. Purpose is to identify the features of the current state of functioning of the education sector and outline the directions of its reform in the conditions of decentralization. Results. The article presents a problem-oriented analysis of the functioning of the education sector in terms of its components: preschool and secondary education, vocational education and higher education, as well as the management and financing of science. The main problems that are characteristic of the field are identified, among which the imperfect mechanism of financing, built on directing the funds for the maintenance of educational institutions, and not ensuring the quality of education according to the principle of "money go after the child", the lack of incentives for professional development of teaching staff, etc., are highlighted. The specifics of functioning and financing of pre-school education by united territorial communities, peculiarities of use of educational subvention are revealed. The problems of vocational education and the need to change approaches to its organization were emphasized. The analysis shows that, despite the positive changes and new opportunities that have emerged in the field of education and due to administrative and financial decentralization, there are risks of not achieving the planned goals. These include: low financial capacity of communities, lack of established standards of educational funding, conflicts about school closures, shortages of professionals with education and work experience who could exercise new authority and manage the on-site education process, and divide responsibility for quality of learning. Possible directions of improvement of the sphere of education are outlined.
Ákos Hajdu, Naghmeh Ivaki, Imre Kocsis, Attila Klenik · 8 authors
Blockchain has become particularly popular due to its promise to support business-critical services in very different domains (e.g., retail, supply chains, healthcare). Blockchain systems rely on complex middleware, like Ethereum or Hyperledger Fabric, that allow running smart contracts, which specify business logic in cooperative applications. The presence of software defects or faults in these contracts has notably been the cause of failures, including severe security problems. In this paper, we use a software implemented fault injection (SWIFI) technique to assess the behavior of permissioned blockchain systems in the presence of faulty smart contracts. We emulate the occurrence of general software faults (e.g., missing variable initialization) and also blockchain-specific software faults (e.g., missing require statement on transaction sender) in smart contracts code to observe the impact on the overall system dependability (i.e., reliability and integrity). We also study the effectiveness of formal verification (i.e., done by solc-verify) and runtime protections (e.g., using the assert statement) mechanisms in detection of injected faults. Results indicate that formal verification as well as additional runtime protections have to complement built-in platform checks to guarantee the proper dependability of blockchain systems and applications. The work presented in this paper allows smart contract developers to become aware of possible faults in smart contracts and to understand the impact of their presence. It also provides valuable information for middleware developers to improve the behavior (e.g., overall fault tolerance) of their systems.
In recent years, there has been a growth of interest in the blockchain technology across a wide range of industries. Blockchain technology has the potential to transform the way businesses operate especially in the automotive industry. The distributed infrastructure and the secure nature of the blockchain technology encourages trust among businesses and consumers. In Mauritius, the automotive industry is facing challenges such as tampering of vehicle information, falsification of mileage and poor traceability which leads to a lack of trust from customers. In this work, an implementation of a proof of concept (POC) for a blockchain-based smart contract application has been proposed and implemented to mitigate these challenges. The automotives use cases: (a) vehicle importation; and (b) vehicle sale and registration have been implemented in the IBM blockchain platform which provides a secure and transparent way to invoke transactions. Finally, the performance and benefits of the Hyperledger Fabric vehicle application have been assessed based on transparency, security, traceability and efficiency.
A.G. Luchkin, О.Л. ЛУКАШЕВА, Н Е Новикова, Vitalik Melnikov · 6 authors
The subject of the study is cryptocurrencies from the perspective of the possibility of using them as a means of payment in the context of economy digitalization. The aim of the work is to assess the possible consequences of the further spread of cryptocurrency in the global financial system and to find ways to overcome them. The article analyzes the history of the emergence and development of money circulation systems from the gold standard to modern conditions for the emergence of cryptocurrencies, and also discusses the possibilities of using cryptocurrencies in fraudulent schemes. As a result of the study, the following tasks were solved: a historical analysis of money circulation systems was carried out; modern trends in the development of modern payment systems were revealed; the possibilities of using electronic and virtual money in modern conditions of digital economy development were analyzed; digital fraud opportunities were evaluated; the ways of regulating cryptographic money turnover were revealed. A historical analysis of monetary systems development enables to identify the objective reasons for the emergence of cryptocurrencies and the need to develop a legal and economic mechanism for their regulation in the digital economy development. Description of cryptocurrency fraud schemes enables to identify possible ways to stop them. The problem of organizational development of the settlement of relations in the field of cryptocurrency exchange, which will prepare the Russian financial system, reduce potential risks and learn how to use the benefits arising from the cryptocurrency turnover, is being solved.