David Hawig, C. Zhou, Sebastian Fuhrhop, Andre S Fialho · 5 authors
BACKGROUND: Distributed ledger technology (DLT) holds great potential to improve health information exchange. However, the immutable and transparent character of this technology may conflict with data privacy regulations and data processing best practices. OBJECTIVE: The aim of this paper is to develop a proof-of-concept system for immutable, interoperable, and General Data Protection Regulation (GDPR)-compliant exchange of blood glucose data. METHODS: Given that there is no ideal design for a DLT-based patient-provider data exchange solution, we proposed two different variations for our proof-of-concept system. One design was based purely on the public IOTA distributed ledger (a directed acyclic graph-based DLT) and the second used the same public IOTA ledger in combination with a private InterPlanetary File System (IPFS) cluster. Both designs were assessed according to (1) data reversal risk, (2) data linkability risks, (3) processing time, (4) file size compatibility, and (5) overall system complexity. RESULTS: The public IOTA design slightly increased the risk of personal data linkability, had an overall low processing time (requiring mean 6.1, SD 1.9 seconds to upload one blood glucose data sample into the DLT), and was relatively simple to implement. The combination of the public IOTA with a private IPFS cluster minimized both reversal and linkability risks, allowed for the exchange of large files (3 months of blood glucose data were uploaded into the DLT in mean 38.1, SD 13.4 seconds), but involved a relatively higher setup complexity. CONCLUSIONS: For the specific use case of blood glucose explored in this study, both designs presented a suitable performance in enabling the interoperable exchange of data between patients and providers. Additionally, both systems were designed considering the latest guidelines on personal data processing, thereby maximizing the alignment with recent GDPR requirements. For future works, these results suggest that the conflict between DLT and data privacy regulations can be addressed if careful considerations are made regarding the use case and the design of the data exchange system.
Purpose The purpose of this paper is to understand the enabling and constraining roles of blockchain technology (BCT) in managerial work practices and conceptualise the technology–performance relationship in supply chain management (SCM). Design/methodology/approach A structured literature review and a theory-driven approach are used. A set of propositions are developed, suggesting how the use of BCT in supply chains can be understood to simultaneously enable and constrain SCM and performance. Findings The analysis identifies four enabling and three constraining blockchain identities to explain how the technology either “facilitates” or “impedes” SCM and supply chain performance. Traceability, which emanates from its ability to provide data immutability, ranks highly as a core innovation of the technology. The blockchain is mainly seen as an opportunity to exploit existing supply chain resources and competencies. Research limitations/implications One limitation of the research is its conceptual nature. Future research should test the developed propositions empirically. Further research should focus on BCT as an opportunity to explore and as a relationship-building technology. More research is also needed focussing on the complex and simultaneous enabling and constraining effects of BCT in supply chains. Originality/value The paper shows the important and complex Janus-faced implications of embedding BCT in supply chains and demonstrates how organisational theory can be applied to explore the relationship between blockchain and SCM.
Various start-up developers and academic researchers have investigated the usage of blockchain as a data storage medium due to the advantages offered by its tamper-proof and decentralized nature. However, there have not been many attempts to provide a standard platform for virtually storing the states of unique tangible entities and their subsequent modifications. In this paper, we propose NFTracer, a non-fungible token tracking proof-of-concept based on Hyperledger Composer and Hyperledger Fabric Blockchain. To achieve the capabilities of our platform, we use NFTracer to build an artwork auction and a real estate auction, which vary in technical complexity and demonstrate the advantages of being able to track entities and their resulting modifications in a decentralized manner. We also present its accompanying modular architecture and system components, and discuss possible future works on NFTracer.
People need a motive to use and maintain a system. In many of the systems we use today, financial rewards and punishments provide a key incentive to participate and abide by the rules. From salaries to traffic tickets, financial motives are often closely tied to a system's viability. Distributed systems such as blockchain also need a mechanism to motivate good behavior. A blockchain must encourage users to maintain the system while preventing a minority of these users from colluding and gaining disproportionate control. Many popular public blockchains use monetary incentives to encourage users to participate and behave appropriately. But these same incentive schemes create more problems than they solve. Mining rewards cause centralization in proof of work chains such as Bitcoin. Validator rewards and punishments invite attacks in proof of stake chains. This paper argues why these incentive schemes are detrimental to blockchain. It also considers a range of other systems-some of which incorporate monetary incentives, some of which do not-to confirm that monetary incentives may be neither necessary nor sufficient for good user behavior.
Panagiotis Chatzigiannis, Foteini Baldimtsi, Igor Griva, Jiasun Li
Abstract Mining is a central operation of all proof-of-work (PoW)-based cryptocurrencies. The vast majority of miners today participate in “mining pools” instead of “solo mining” in order to lower risk and achieve a more steady income. However, this rise of participation in mining pools negatively affects the decentralization levels of most cryptocurrencies. In this work, we look into mining pools from the point of view of a miner: We present an analytical model and implement a computational tool that allows miners to optimally distribute their computational power over multiple pools and PoW cryptocurrencies (i.e. build a mining portfolio), taking into account their risk aversion levels. Our tool allows miners to maximize their risk-adjusted earnings by diversifying across multiple mining pools. Our underlying techniques are drawn from both the areas of financial economy and computer science since we use computer science-based approaches (i.e. optimization techniques) to experimentally prove how parties (and in particular miners) interact with cryptocurrencies in a way of increasing their Sharpe ratio. To showcase our model, we run an experiment in Bitcoin historical data and demonstrate that a miner diversifying over multiple pools, as instructed by our model/tool, receives a higher overall Sharpe ratio (i.e. average excess reward over its standard deviation/volatility).
Various start-up developers and academic researchers have investigated the\nusage of blockchain as a data storage medium due to the advantages offered by\nits tamper-proof and decentralized nature. However, there have not been many\nattempts to provide a standard platform for virtually storing the states of\nunique tangible entities and their subsequent modifications. In this paper, we\npropose NFTracer, a non-fungible token tracking proof-of-concept based on\nHyperledger Composer and Hyperledger Fabric Blockchain. To achieve the\ncapabilities of our platform, we use NFTracer to build an artwork auction and a\nreal estate auction, which vary in technical complexity and demonstrate the\nadvantages of being able to track entities and their resulting modifications in\na decentralized manner. We also present its accompanying modular architecture\nand system components, and discuss possible future works on NFTracer.\n
Luke Zeng, Shawn Xin, Avadesian Xu, Thomas Pang · 6 authors
In this paper, we will present a new PoW consensus algorithm used in Seele's main-net, MPoW (Matrix-Proof-of-Work). Compared to Bitcoin's PoW consensus algorithm, MPoW requires miners to compute the determinants of submatrices from a matrix constructed with n hashes other than brute-force-hashing using a hash function to find the target. This paper will evaluate this algorithm's compatibility with difficulty adjustment. Then we will discuss its efficiency in countering machines with hashrate advantage, and its feasibility to personal computers. We believe more innovative consensus protocols can be developed based on this algorithm.
There is a growing interest today in blockchain technology as a possible foundation for the future global financial ecosystem. However, in order for this future financial ecosystem to be truly global, with a high degree of interoperability and stability, a number challenges need to be addressed related to infrastructure security. One key aspect concerns the security and robustness of the systems that participate in the blockchain peer-to-peer networks. In this paper we discuss the notion of the decentralized trusted computing base as an extension of the TCB concept in trusted computing. We explore how a decentralized TCB can be useful to (i) harden individual nodes and systems in the blockchain infrastructure, and (ii) be the basis for secure group-oriented computations making within the P2P network of nodes that make-up the blockchain system.
The increasing number of intelligent Machine-to-Machine Communication (M2M) devices in the end-user domain provide good resources for creating and sharing M2M application services. Therefore, transferring the role of a traditional centralized service provider to decentralized peers (end-users) acting as service providers is very promising. However, the future of decentralized M2M application services which are independently provided or consumed by several end-users in the M2M community depends on trust. Untrustworthy peers trying to deploy malfunctioning services for others mitigate the benefits of decentralized systems. Nowadays, the concept of distributed ledger and blockchain has an increased popularity regarding trustless computing among communities operating without centralized authorities. This research publication provides a comprehensive analysis and approach merging the concepts of M2M application services, trust and distributed ledger technologies. Moreover, this publication presents an optimized Trust Evaluation System which is used to ensure trustworthiness among peers in a M2M community. To improve the Trust Evaluation System the integration of blockchain for data storage is introduced. Additionally, blockchain technology is used to extend the existing trust model of the Trust Evaluation System to enable tamper-proof data and detection of untrustworthy peers. This publication reviews several existing approaches in the academic and industry sector to highlight the limitations of the blockchain regarding the consensus and proposes a novel Trust Consensus Protocol. This research publication also provides a practical evaluation of the proposed protocol.
The development of blockchain technologies has enabled the trustless execution of so-called smart contracts, i.e. programs that regulate the exchange of assets (e.g., cryptocurrency) between users. In a decentralized blockchain, the state of smart contracts is collaboratively maintained by a peer-to-peer network of mutually untrusted nodes, which collect from users a set of transactions (representing the required actions on contracts), and execute them in some order. Once this sequence of transactions is appended to the blockchain, the other nodes validate it, re-executing the transactions in the same order. The serial execution of transactions does not take advantage of the multi-core architecture of modern processors, so contributing to limit the throughput. In this paper we propose a true concurrent model of smart contract execution. Based on this, we show how static analysis of smart contracts can be exploited to parallelize the execution of transactions.
The Internet of Things (IoT) has caused a revolutionary paradigm shift in computer networking. After decades of human-centered routines, where devices were merely tools that enabled human beings to authenticate themselves and perform activities, we are now dealing with a device-centered paradigm: the devices themselves are actors, not just tools for people. Conventional identity access management (IAM) frameworks were not designed to handle the challenges of IoT. Trying to use traditional IAM systems to reconcile heterogeneous devices and complex federations of online services (e.g., IoT sensors and cloud computing solutions) adds a cumbersome architectural layer that can become hard to maintain and act as a single point of failure. In this paper, we propose UniquID, a blockchain-based solution that overcomes the need for centralized IAM architectures while providing scalability and robustness. We also present the experimental results of a proof-of-concept UniquID enrolment network, and we discuss two different use-cases that show the considerable value of a blockchain-based IAM.
This study has been undertaken to all the segments and functioning of BlockChain and Cryptocurrency. They have become one of the hottest topics in the tech and finance world. This technology directly affects the financial world. It is safe, secure, and fast and expanding with a predicted rate of 42.8% by 2020. The immense potential this technology holds for future growth gives rise to the concept of BitCoin, Ethereum, etc. There are more than 2000 startups based on BlockChain Technology with a high market inclination.
Isaac Sheff, Xinwen Wang, Haobin Ni, Robbert van Renesse · 5 authors
We present Charlotte, a framework for composable, authenticated distributed data structures. Charlotte data is stored in blocks that reference each other by hash. Together, all Charlotte blocks form a directed acyclic graph, the blockweb; all observers and applications use subgraphs of the blockweb for their own data structures. Unlike prior systems, Charlotte data structures are composable: applications and data structures can operate fully independently when possible, and share blocks when desired. To support this composability, we define a language-independent format for Charlotte blocks and a network API for Charlotte servers. An authenticated distributed data structure guarantees that data is immutable and self-authenticating: data referenced will be unchanged when it is retrieved. Charlotte extends these guarantees by allowing applications to plug in their own mechanisms for ensuring availability and integrity of data structures. Unlike most traditional distributed systems, including distributed databases, blockchains, and distributed hash tables, Charlotte supports heterogeneous trust: different observers may have their own beliefs about who might fail, and how. Despite heterogeneity of trust, Charlotte presents each observer with a consistent, available view of data. We demonstrate the flexibility of Charlotte by implementing a variety of integrity mechanisms, including consensus and proof of work. We study the power of disentangling availability and integrity mechanisms by building a variety of applications. The results from these examples suggest that developers can use Charlotte to build flexible, fast, composable applications with strong guarantees.
The Committee Selection Mechanism can select multiple users of blockchain network to execute a consensus algorithm, such as PBFT. In order to guarantee two properties, the mathematical form of the mechanism is relatively limited. Further, if the mechanism is used in open network, it will bring about an increase in efficiency, but it will reduce the security and practicability of the blockchain network.
The notion of risk plays a central role in economics, finance, health, psychology, law and elsewhere, and is prevalent in managing challenges and resources in day-to-day life. In recent work, Duncan Pritchard (2015, 2016) has argued against the orthodox probabilistic conception of risk on which the risk of a hypothetical scenario is determined by how probable it is, and in favour of a modal conception on which the risk of a hypothetical scenario is determined by how modally close it is. In this article, we use Pritchard's discussion as a springboard for a more wide-ranging discussion of the notion of risk. We introduce three different conceptions of risk: the standard probabilistic conception, Pritchard's modal conception, and a normalcy conception that is new (though it has some precursors in the psychological literature on risk perception). Ultimately, we argue that the modal conception is ill-suited to the roles that a notion of risk is required to play and explore the prospects for a form of pluralism about risk, embracing both the probabilistic and the normalcy conceptions. We take the view that a risk judgment always implicates a body of evidence, which we refer to as the background evidence. In cases where the background evidence is not made explicit, we take it to be supplied by the context of utterance and, in typical cases, to be the evidence possessed by the one making the judgment. That is, we are inclined towards a contextualist semantics for utterances such as 3 and 4, on which their truth conditions feature an evidence parameter, the value of which is fixed by the context. The semantics of such utterances is not, however, our primary concern here. As well as making categorical risk judgments such as the above, we often make comparisons. While we may judge that the risk of a plane crash is very low, we may also judge that there is a higher risk of a car crash on the way to the airport. As well as judging that there's a high risk of food poisoning at a particular restaurant, we might also judge that there is a lower risk of food poisoning at the restaurant next door. Moreover, while we often speak about the riskiness of feared events, such as plane crashes, food poisoning, etc., we can also assess the risk of states of affairs. For instance, before drilling into the wall of a 1970s West Australian house, one might assess the risk that the wall contains asbestos, or jurors in a criminal trial, when contemplating a guilty verdict, might consider the risk that the defendant is innocent, or a mountaineer may ponder the risk that the snow conditions are unfavourable for a climb. Here, we treat propositions as the primary bearers of risk, with the riskiness of an event or state of affairs corresponding to the riskiness of the proposition that the event occurs, or the state of affairs obtains. As well as making judgments about the risk of specific events and states of affairs, people also assess the risk of activities or decisions, saying things like ‘Drilling into this wall is risky’, ‘It would be risky to attempt a climb under these conditions’. These judgments are important to understanding the connections between risk and decision making but we put them to one side here. According to the probabilistic of risk, the risk of a proposition is determined by the of higher the the higher the risk. this the risk of is higher the risk of in is more probable is. The be as the background evidence. 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Purpose – the purpose of this study is to analyse the cryptocurrency market and to forecast household investments in it from a theoretical and practical point of view. Research methodology – in order to achieve the aim of the article, scientific literature and statistical data analysis, comparative analysis and SWOT analysis were done. Also, ARIMA forecasting model was adapted to forecast Household investment in cryptocurrencies. Findings – the first part of the study presents the theoretical aspects of cryptocurrencies. An overview of the cryptocurrencies and their market is provided, focusing on the concept of Bitcoins, its’ mining and technical principles of operation. The second part of this study is intended to analyse the cryptocurrencies market and its dynamics. In the last part of the research tendencies of household investments in cryptocurrencies are examined for the period of 2016–2019 according to the data from cryptocurrency exchange. Also, household investments in cryptocurrencies are analysed and major future investment trends and seasonality are identified as well. Household future investment in cryptocurrencies is also predicted. Research limitations – data used in the research only includes currency exchange information, that may be inaccurate when concluding the main trends of the market. Practical implications – the practical results of the study may be useful for households interested in investing, especially in risky investment alternatives. Results of the research justify the dynamics of the currency market and the fluctuation of cryptocurrencies’ prices that shows that investment in cryptocurrencies is very variable, unstable and risky. Originality/Value – cryptocurrencies market is particularly dynamic and fast-changing, so the newest scientific investigations are urgent. In this research, an attempt was made to forecast household investment in main cryptocurrencies
Purpose – to investigate the possible influence of bitcoins and the Blockchain on exchange rates of selected fiat currencies by using quantitative analysis methods. Research methodology – the importance, risks/opportunities are examined by studying scientific literature regarding cryptocurrencies and decentralization. The influence of bitcoins itself is examined by using regression analysis, ANOVA, descriptive statistics, correlation matrix, and VIF. Findings – impart negative relation between Bitcoin money supply and exchange rates (USD/EUR) and a positive relation between Bitcoin inflation rate and exchange rates (USD/EUR). However, the actual influence is too negligible to make any significant affection for the conventional financial sector yet digitalization and decentralization are imminent. Research limitations – only a few analyses have been conducted in a quantitative manner regarding cryptocurrencies impact. The influence of cryptocurrencies increased from 2011; phenomenon lacks long time data and examples to conduct an analysis model that applies to all assumptions without exceptions. Practical implications – enterprises can embrace decentralization and digital money to keep up with the fast-growing market changes, improve transparency, and reduce costs. Close relation with fintech is indispensable; it promotes economic growth and accelerates the development of advanced operating practices. Originality/Value – the interest in digital money and peer-to-peer payments constantly occupy greater importance of financial market and trading manner. Their influence is widely discussed but lacks quantitative researches based on actual historical data
Νικόλαος Αλεξόπουλος, Emmanouil Vasilomanolakis, Stéphane Le Roux, Steven Rowe · 5 authors
Sophisticated mass attacks, especially when exploiting zero-day vulnerabilities, have the potential to cause destructive damage to organizations and critical infrastructure. To timely detect and contain such attacks, collaboration among the defenders is critical. By correlating real-time detection information (alerts) from multiple sources (collaborative intrusion detection), defenders can detect attacks and take the appropriate defensive measures in time. However, although the technical tools to facilitate collaboration exist, real-world adoption of such collaborative security mechanisms is still underwhelming. This is largely due to a lack of trust and participation incentives for companies and organizations. This paper proposes TRIDEnT, a novel collaborative platform that aims to enable and incentivize parties to exchange network alert data, thus increasing their overall detection capabilities. TRIDEnT allows parties that may be in a competitive relationship, to selectively advertise, sell and acquire security alerts in the form of (near) real-time peer-to-peer streams. To validate the basic principles behind TRIDEnT, we present an intuitive game-theoretic model of alert sharing, that is of independent interest, and show that collaboration is bound to take place infinitely often. Furthermore, to demonstrate the feasibility of our approach, we instantiate our design in a decentralized manner using Ethereum smart contracts and provide a fully functional prototype.
A phishing attack is one of the severe threats to the smartphone users. As per the recent lookout report, mobile phishing attack is increasing 85% year to year and going to become a significant threat to the smartphone users. This social engineering attack attempts to get the user’s password by disguising as trusted service provider. Most of the smartphone users are using the Internet services outside of the traditional firewall. Cloud-based documents are one of the primary targets of this phishing attack in mobile cloud computing. Also, most smartphone users are using the cloud storage in their device. To secure against this password attack in a mobile cloud environment, we propose a new authentication scheme to provide novel security to the mobile cloud services. This scheme will verify the user and service provider without transmitting the password using the Zero-knowledge proof based authentication protocol. Moreover, the proposed scheme will provide mutual authentication between the communication entities. The effectiveness of proposed scheme would be verified using protocol verification tool called Scyther.
Electronic systems are ubiquitous today, playing an irreplaceable role in our personal lives as well as in critical infrastructures such as power grid, satellite communication, and public transportation. In the past few decades, the security of software running on these systems has received significant attention. However, hardware has been assumed to be trustworthy and reliable "by default" without really analyzing the vulnerabilities in the electronics supply chain. With the rapid globalization of the semiconductor industry, it has become challenging to ensure the integrity and security of hardware. In this paper, we discuss the integrity concerns associated with a globalized electronics supply chain. More specifically, we divide the supply chain into six distinct entities: IP owner/foundry (OCM), distributor, assembler, integrator, end user, and electronics recycler, and analyze the vulnerabilities and threats associated with each stage. To address the concerns of the supply chain integrity, we propose a blockchain-based certificate authority framework that can be used to manage critical chip information such as electronic chip identification (ECID), chip grade, transaction time, etc. The decentralized nature of the proposed framework can mitigate most threats of the electronics supply chain, such as recycling, remarking, cloning, and overproduction.
Open access
Physical Unclonable Functions (PUFs) and Hardware Security
Neuroscience and Neural Engineering
Integrated Circuits and Semiconductor Failure Analysis
Abbas Yazdinejad, Reza M. Parizi, Ali Dehghantanha, Kim-Kwang Raymond Choo
5G mobile networks provide additional benefits in terms of lower latency, higher data rates, and more coverage, in comparison to 4G networks, and they are also coming close to standardization. For example, 5G has a new level of data transfer and processing speed that assures users are not disconnected when they move from one cell to another; thus, supporting faster connection. However, 5G comes with its own technical challenges, such as those relating to authentication handover and user privacy protection. In 5G, for example, the frequent displacement of the users among the cells as a result of repeated authentication handovers often lead to a delay, contradicting the 5G objectives. Using inefficient authentication handover could also cause performance degradation among heterogeneous 5G cells, and increases the possibility of occurring user privacy and security issues. In this paper, we propose a new authentication approach that utilizes blockchain and software defined networking (SDN) techniques to remove the unnecessary re-authentication in repeated handover among heterogeneous cells. The proposed approach is designed to assure the low delay, appropriate for the 5G network in which users are replaced with the least delay among heterogeneous cells using their public and private keys provided by the devised blockchain component while protecting their privacy. In our comparison between Proof-of-Work (POW)-based and network-based models, the delay of our authentication handover is shown to be less than 1 ms. Also, our approach demonstrates less signaling overhead and energy consumption compared to peer models.
The recent adoption of blockchain technologies and open permissionless networks suggest the importance of peer-to-peer atomic cross-chain transaction protocols. Users should be able to atomically exchange tokens and assets without depending on centralized intermediaries such as exchanges. Recent peer-to-peer atomic cross-chain swap protocols use hashlocks and timelocks to ensure that participants comply to the protocol. However, an expired timelock could lead to a violation of the all-or-nothing atomicity property. An honest participant who fails to execute a smart contract on time due to a crash failure, denial of service attacks or even network delays might end up losing assets. Although a crashed participant is the only participant who ends up worse off, current proposals are unsuitable for atomic cross-chain transactions in asynchronous environments where crash failures and network delays are the norm. In this paper, we present AC 3 WN, the first decentralized all-or-nothing atomic cross-chain commitment protocol. The redeem and refund events of the smart contracts that exchange assets are modeled as conflicting events. An open permissionless network of witnesses is used to guarantee that conflicting events could never simultaneously occur and either all smart contracts in an atomic cross-chain transaction are redeemed or all of them are refunded.
The implementation of fiscal balance policy is done through budget allocation for local governments, include balance fund. Furthermore, the policy has also been meant to reduce imbalance fund resources between central and local governments and to minimize fiscal gap among local governments as well. The general allocation fund (DAU) is allocated with aim to even distribution of financial capability interregional. The allocation is to finance local governments' need regarding implementation of decentralization system. The use fund is adjusted to priority and need each local government (block grant)
Blockchain technology has an enormous scope to revamp the healthcare system in many ways as it improves the quality of healthcare by data sharing among all the participants, selective privacy and ensuring data safety. This paper explores the basics of blockchain, its applications, quality of experience and advantages in disease surveillance over the other widely used real-time and machine learning techniques. The other real-time surveillance systems lack scalability, security, interoperability, thus making blockchain as a choice for surveillance. Blockchain offers the capability of enhancing global health security and also can ensure the anonymity of patient data thereby aiding in healthcare research. The recent epidemics of re-emerging infections such as Ebola and Zika have raised many concerns regarding health security which resulted in strengthening the surveillance systems. We also discuss how blockchains can help in identifying the threats early and reporting them to health authorities for taking early preventive measures. Since the Global Health Security Agenda addresses global public health threats (both infectious and NCDs); strengthen the workforce and the systems; detect and respond rapidly and effectively to the disease threats; and elevate global health security as a priority. The blockchain has enormous potential to disrupt many current practices in traditional disease surveillance and health care research.