Pierluigi Martino, Kevin Jue Wang, Cristiano Bellavitis, Carlos M. DaSilva
Blockchain is a revolutionary technology that allows people to record transactions on a digital, decentralized, distributed ledger, without any central authority. Some consider this technology as “the trust machine” and cryptocurrency is without doubt the most notable by-product of the blockchain revolution. Initial coin offering (ICO) is a new way to raise entrepreneurial finance, newly created cryptocurrencies are being sold to the public by start-ups in exchange of capital. This chapter intends to clarify this phenomenon by explaining the concepts of blockchain technology, cryptocurrency and ICO, in order to provide valuable insights into this new trend of entrepreneurial finance.
With the explosive growth in cryptocurrencies over the last couple of years, the cost of mining these technologies (the process through which users devote CPU power to operate the underlying blockchains) have similarly exploded. This paper examines one overarching question regarding this issue â what factor or factors explain the geographic distribution of cryptocurrency nodes (mining operations) across the world? In exploring this question, this research considers electricity price, internet access, Tor network relays, and others. Using node distribution data for Bitcoin and Ethereum â the two largest cryptocurrencies â this paper analyzes cross-sectional and panel data regression models, and establishes that electricity price has not played a significant role in this distribution up to this point, and concludes that the historical association between Tor relays and Bitcoin use has had a much greater impact. Lastly, this paper discusses the broader implications of its findings, and the potential areas of research for further understanding of this field.
Frode Kjærland, Maria Meland, Are Oust, Vilde Øyen
The purpose of this study is to uncover factors that explain Bitcoin's price fluctuations. The price of the cryptocurrency Bitcoin is volatile and has increased from zero in 2009 to more than 19500 USD in December 2017. To explain the price movements we have estimated two autoregressive distributed lag models by using ordinary least squares regression. The data includes 279 weekly observations from 18.09.2011 to 05.02.2017 (before the extreme development from the summer of 2017). The dependent variable is the Bitcoin price and the analysis has examined nine independent variables. Our main finding and contribution is that political incidents and statements (“shocks”) are significant drivers of Bitcoin's price. Moreover, the volume of Bitcoin and Bitcoin's price has a significant, negative relationship. The interest of Bitcoin, measured by Google searches, has a positive, significant relationship with Bitcoin's price. The study does not find evidence for Bitcoin being a safe haven investment.
Patrick Li, Scott D. Nelson, Bradley Malin, You Chen
Background: Access to accurate and complete medication histories across healthcare institutions enables effective patient care. Histories across healthcare institutions currently rely on centralized systems for sharing medication data. However, there is a lack of efficient mechanisms to ensure that medication histories transferred from one institution to another are accurate, secure, and trustworthy. Methods: In this article, we introduce a decentralized medication management system (DMMS) that leverages the advantages of blockchain to manage medication histories. DMMS is realized as a decentralized network under the hyperledger fabric framework. Based on the network, we designed an architecture, within which each prescriber can create prescriptions for each patient and perform queries about historical prescriptions accordingly. Finally, we analyzed the advantages of DMMS over centralized systems in terms of accuracy, security, trustworthiness, and privacy. Results: We developed a proof of concept to showcase DMMS. In this system, a prescriber prescribes medications for a patient and then encrypts the prescriptions via the patient’s public keys. Patients can query their own prescriptions from different histories across healthcare institutions and then decrypt the prescriptions via their private keys. At the same time, a prescriber can query a patient’s prescription records across healthcare institutions after approval from the patient. Analytic results show that DMMS can improve security, trustworthiness, and privacy in medication history sharing and exchanging across healthcare institutions. In addition, we discuss the potential for DMMS in e-prescribing markets. Conclusions: This study shows that a distributed secure ledger can enable reliable, interoperable, and accurate medication history sharing. Keywords: Blockchain Ledger, Decentralized, Hyperledger Fabric Framework, Medication Histories Please see a related Letter to the Editor (https://doi.org/10.30953/bhty.v2.98), and its response (https://doi.org/10.30953/bhty.v2.108)
Recently, Blockchain is considered as one of the main powerful techniques in security and privacy domains. It is considered as the promised security concept for replacing the current third parities trusting solutions. This could be achieved by mixing some cryptography techniques, consensus algorithms alongside with some peer-to-peer communication protocols. In this paper, to meet the requirement of distributed structure in the eHealth Records (EHRs) system, we propose a novel protocol to achieve a perfect privacy preserving for the patient namely Pseudonym Based Encryption with Different Authorities (PBE-DA) by applying the concept of Blockchain on the healthcare communication entities in an e-health platform. Therefore, PBE-DA will be used to help the patient anonymously to access, check or update his sensitive data on EHRs system. Moreover, we analyzed not only the public blockchain tier between the different EHRs cloud provider but also another Blockchain tier between the patient sensors (IoT devices used to do some patient measurements) and the patient system as a gateway for the whole healthcare platform.
Guglielmo Maria Caporale, Alex Plastun, Viktor Oliinyk
This paper investigates the role of the frequency of price overreactions in the cryptocurrency market in the case of BitCoin over the period 2013–2018. Specifically, it uses a static approach to detect overreactions and then carries out hypothesis testing by means of a variety of statistical methods (both parametric and non-parametric) including ADF tests, Granger causality tests, correlation analysis, regression analysis with dummy variables, ARIMA and ARMAX models, neural net models, and VAR models. Specifically, the hypotheses tested are whether or not the frequency of overreactions (i) is informative about Bitcoin price movements (H1) and (ii) exhibits no seasonality (H2). On the whole, the results suggest that it can provide useful information to predict price dynamics in the cryptocurrency market and for designing trading strategies (H1 cannot be rejected), whilst there is no evidence of seasonality (H2 cannot be rejected).
Youness Tribis, Abdelali El Bouchti, Houssine Bouayad
Groundbreakingly, blockchain technology (BCT) has gained widespread acceptance and importance in the last few years. Implemented in different areas of applications such as social and legal industries, finance, smart property, and supply chain networks. This technology assures immutability and integrity of data without the need of a third trusted party. Furthermore, BCT could guarantee a transparent and decentralized transaction system in businesses and industries. Even though general research has been done in the BCT, however, there is a lack of systematic analysis on current research challenges regarding how BCT is effectively applicable in supply chain management (SCM). A systematic literature review (SLR) of SCM based on blockchain does not exist yet. This work aims to explore and analyse the state-ofthe-art on the BCT applications for SCM. We synthesize existing evidence, and identify gaps, available in the literature. The survey uses a systematic mapping study (SMS) method to examine 40 extracted primary studies from scientific databases.
Blockchain technology is having a deep impact on the financial and technical sectors providing a mechanism for the creation of decentralized currencies and a number of applications in different fields.At the core of the technology there is a consensus protocol enabling the maintenance of a distributed ledger.In general current systems are complex schemes that implement a combination of cryptographic algorithm, distributed techniques, and incentive driven behaviour.In this paper we focus on three of the most diffused platforms, i.e.Bitcoin, Ripple, and Ethereum, and provide a comparative analysis of their most important features such as the architecture, the scripting language, the economic and security properties.
Decentralised issued crypto "currencies", like bitcoin, have the potential to drastically change the existing retail payment system and even the monetary system. Insights into the factors that influence their adoption are therefore crucial. Using a large representative sample of retailers that sell their products online, we find that acceptance of crypto payments is currently modest (2%), but there is substantial interest among retailers to adopt crypto payments in the near future. Consumer demand, net transactional benefits and perceived adoption effort influence adoption intention and actual acceptance by retailers. Regarding non-financial factors, our findings suggest that service providers who act as intermediaries between retailers, their customers, and providers of payment instruments play a crucial role as facilitators of competition and innovation in the online retail payments market by lowering such barriers. The most serious barrier for crypto acceptance seems to be a lack of consumer demand. Information from consumers indicate that those who possess cryptos, don't use it for online payments. It seems therefore unlikely that the adoption of cryptos by retailers will increase substantially, making it highly unlikely that cryptos like bitcoin will drastically change the existing retail payment system.
Do Bitcoin and other cryptocurrencies play a useful social role, or do they represent a social waste? Bitcoin is a decentralized recordkeeping system, with updating of the record of transactions in the blockchain.
A landmark security property of smart contracts is liquidity: in a non-liquid contract, it may happen that some funds remain frozen. The relevance of this issue is witnessed by a recent liquidity attack to the Ethereum Parity Wallet, which has frozen $${\sim }160M$$ USD within the contract, making this sum unredeemable by any user. We address the problem of verifying liquidity of Bitcoin contracts. Focussing on BitML, a contracts DSL with a computationally sound compiler to Bitcoin, we study various notions of liquidity. Our main result is that liquidity of BitML contracts is decidable, in all the proposed variants. To prove this, we first transform the infinite-state semantics of BitML into a finite-state one, which focusses on the behaviour of any given set of contracts, abstracting the context moves. With respect to the chosen contracts, this abstraction is sound and complete. Our decision procedure for liquidity is then based on model-checking the finite space of states of the abstraction.
The article is devoted to research of reliability and security of distributed ledger technology.A distributed ledger is a replicated database operating on the basis of decentralized networks.A vivid example of using distributed ledger technology is blockchain technology.Data protection against spoofing in using distributed ledgers is ensured by sequential hashing, asymmetric cryptography, and a decentralized network.
Md. Abdur Rahman, M. Shamim Hossain, George Loukas, Elham Hassanain · 7 authors
Mobile edge computing (MEC) is being introduced and leveraged in many domains, but few studies have addressed MEC for secure in-home therapy management. To this end, this paper presents an in-home therapy management framework, which leverages the IoT nodes and the blockchain-based decentralized MEC paradigm to support low-latency, secure, anonymous, and always-available spatiotemporal multimedia therapeutic data communication within an on-demand data-sharing scenario. To the best of our knowledge, this non-invasive, MEC-based IoT therapy platform is first done by our group. This platform can provide a full-body joint range of motion data for physically challenged individuals in a decentralized manner. With MEC, the framework can provide therapy diagnostic and analytical data on demand to a large portion of humanity who are either born with disabilities or became disabled due to accidents, war-time injuries, or old age. For security, the framework uses blockchain–Tor-based distributed transactions to preserve the therapeutic data privacy, ownership, generation, storage, and sharing. Our initial test results from a complete implementation of the framework show that it can support a sufficiently large number of users without considerable increase in mean processing time.
Chao Liu, Kok Keong Chai, Xiaoshuai Zhang, Eng Tseng Lau · 5 authors
The electric vehicle (EV) charging scheme can reduce the power generation costs and improve the smart grid resilience. However, the huge penetrations of EVs can impact the voltage stability and operating costs. In this paper, a novel EV participation charging scheme is proposed for a decentralized blockchain-enabled smart grid system. Our objectives are to minimize the power fluctuation level in the grid network and the overall charging cost for EV users. We first formulate the power fluctuation level problem of the smart grid system that take into accounts of EV battery capacities, charging rates, and EV users charging behavior. And then, we propose a novel adaptive blockchain-based electric vehicle participation (AdBEV) scheme that uses the Iceberg order execution algorithm to obtain an improved EV charging and discharging schedule. The simulation results show the proposed scheme outperforms the scheme that applying genetic algorithm approach in term of lowering the power fluctuation level and overall charging costs.
Blockchain is a new distributed and decentralized technology, and gradually attracts worldwide attention, but it is vulnerable to quantum attacks that would solve elliptic curve digital logarithm problem, which is mainly used for transaction authentication in blockchain. The key needed for authentication comes from the wallet. To ensure that the size of the wallet is fixed and easy to manage, deterministic wallets are required to be used. But if existing anti-quantum signature schemes, such as lattice-based signature are used directly in blockchain to solve the problem, it would have made the wallet bloat. In this paper, we present a novel anti-quantum transaction authentication scheme in the blockchain. In order to construct lightweight nondeterministic wallets, the key point is that public and private keys are generated from a set of master public and private key(Seed Key). We leverage on Bonsai Trees technology and propose a new authentication method which can extend a lattice space to multiple lattice spaces accompanied by the corresponding key. Every signature of a transaction uses a lattice space so as to ensure the randomness and the security of the master private key. And we give the complete security proof and analysis. This paper provides the theoretical support for the application of blockchain in the post quantum age.
Currently, Internet of Things (IoT) and blockchain technologies are experiencing exponential growth in academia and industry. Generally, IoT is a centralized system whose security and performance mainly rely on centralized servers. Therefore, users have to trust the centralized servers; in addition, it is difficult to coordinate external computing resources to improve the performance of IoT. Fortunately, the blockchain may provide this decentralization, high credibility and high security. Consequently, blockchain-based IoT may become a reasonable choice for the design of a decentralized IoT system. In this paper, we propose a novel blockchain-based threshold IoT service system: BeeKeeper. In the BeeKeeper system, servers can process a user's data by performing homomorphic computations on the data without learning anything from them. Furthermore, any node can become a leader's server if the node and the leader desire so. In this way, BeeKeeper's performance can continually increase by attracting external computing resources to join in it. Moreover, malicious nodes can be scrutinized. In addition, BeeKeeper is fault tolerant since a user's BeeKeeper protocol may work smoothly as long as a threshold number of its servers are active and honest. Finally, we deploy BeeKeeper on the Ethereum blockchain and give the corresponding performance evaluation. In our experiments, servers can generate their response with about 107 ms. Moreover, the performance of BeeKeeper mainly depends on the blockchain platform. For instance, the response time is about 22.5 s since the block interval of Ethereum blockchain is about 15 s. In fact, if we use some other blockchain with short block interval, the response time may be obviously short.
Implementing smart contracts to automate the performance of high-value over-the-counter (OTC) financial derivatives is a formidable challenge. Due to the regulatory framework and the scale of financial risk if a contract were to go wrong, the performance of these contracts must be enforceable in law and there is an absolute requirement that the smart contract will be faithful to the intentions of the parties as expressed in the original legal documentation. Formal methods provide an attractive route for validation and assurance, and here we present early results from an investigation of the semantics of industry-standard legal documentation for OTC derivatives. We explain the need for a formal representation that combines temporal, deontic and operational aspects, and focus on the requirements for the temporal aspects as derived from the legal text. The relevance of this work extends beyond OTC derivatives and is applicable to understanding the temporal semantics of a wide range of legal documentation.
Atin Angrish, Benjamin Craver, Mahmud Hasan, Binil Starly
With product customization an emerging business opportunity, organizations must find ways to collaborate and enable sharing of information in an inherently trust-less network. In this paper, we propose – “FabRec”: a decentralized approach to handle manufacturing information generated by various organizations using blockchain technology. We propose a system in which a decentralized network of manufacturing machines and computing nodes can enable automated transparency of an organization’s capability, third party verification of such capability through a trail of past historic events and automated mechanisms to drive paperless contracts between participants using ‘smart contracts’. Our system decentralizes critical information about the manufacturer and makes it available on a peer-to-peer network composed of fiduciary nodes to ensure transparency and data provenance through a verifiable audit trail. We present a testbed platform through a combination of manufacturing machines, system-on-chip platforms and computing nodes to demonstrate mechanisms through which a consortium of disparate organizations can communicate through a decentralized network. Our prototype testbed demonstrates the value of computer code residing on a decentralized network for verification of information on the blockchain and ways in which actions can be autonomously initiated in the physical world. This paper intends to expose system elements in preparation for much larger field tests through the working prototype and discusses the future potential of blockchain for manufacturing IT.
Krishnendu Chatterjee, Amir Kafshdar Goharshady, Yaron Velner
Smart contracts are computer programs that are executed by a network of mutually distrusting agents, without the need of an external trusted authority. Smart contracts handle and transfer assets of considerable value (in the form of crypto-currency like Bitcoin). Hence, it is crucial that their implementation is bug-free. We identify the utility (or expected payoff) of interacting with such smart contracts as the basic and canonical quantitative property for such contracts. We present a framework for such quantitative analysis of smart contracts. Such a formal framework poses new and novel research challenges in programming languages, as it requires modeling of game-theoretic aspects to analyze incentives for deviation from honest behavior and modeling utilities which are not specified as standard temporal properties such as safety and termination. While game-theoretic incentives have been analyzed in the security community, their analysis has been restricted to the very special case of stateless games. However, to analyze smart contracts, stateful analysis is required as it must account for the different program states of the protocol. Our main contributions are as follows: we present (i)~a simplified programming language for smart contracts; (ii)~an automatic translation of the programs to state-based games; (iii)~an abstraction-refinement approach to solve such games; and (iv)~experimental results on real-world-inspired smart contracts.