The major reason of performing this study is to examine volatility of the Bitcoin prices. As known, Bitcoin became more popular when its price movements changed radically. It has been increasing for years since the date of first issuance in 2010 and reached highest level in its history by testing 19,345 USD. Based on this price movement, risk and returns are taken together for making investment in Bitcoin since huge decreasing observed in respond to the these increases. Methodology -In this study, Bitcoin prices are analyzed monthly basis through the time series analysis. Data related to closing prices of Bitcoin are obtained from investing.com web site. We established analysis based on sample consist of Bitcoin prices for the period between 2016 and 2019. Augmented Dickey Fuller (ADF) and Phillips Perron (PP) unit root test is applied to find out whether series are stationary or not. Findings-According to test results, the series of Bitcoin prices are not stationary yet. Although different fluctuating degree can be seen by years, generally it can be stated that Bitcoin prices are still volatile. Conclusion-Based on findings, Bitcoin prices may still be considered as volatile instrument. Therefore, investors should be careful when they want to include this investment tool to the portfolio since it represents risky instrument properties.
Observing the rapid uptake and active use of virtual currencies that are not found in every country in the world, regulators are asking questions about the ability to control and regulate their operations. Therefore, the article describes approaches to determining the economic nature of virtual currencies and analyzes their legal regulation and transactions with them in the world and in Ukraine. The status and official attitude of the regulatory bodies of different countries, consolidation of legislation and taxation of virtual currencies are reflected. In recent years, there have been significant changes in the attitude of most cryptocurrencies in most of the leading countries of the world, from “illegal payment” to “promising financial instrument”. The increasing interest of government in progressive innovation has led to an increase in the influx of new entrants (both individuals and institutions) who are actively using virtual currencies. Yes, cryptocurrencies have caused a lot of concern about the risks they may bring since the first digital currency, Bitcoin. Over a period of time, cryptocurrency exchanges have been steadily increasing their interest in underwriting to ensure the secure process of exchanging and buying cryptocurrencies, reducing theft. Virtual currencies contain a large amount of capitalization in terms of fiat currencies, but the disorder and even the unstable state of cryptocurrencies, as well as the lack of historical loss data, complicate the process of controlling their turnover. However, given the interest, popularity and attention of the media, many, including lawyers, political scientists, economists, are trying to understand the basics of technology and its implications for politicians and other departments. The development of blockchain-based cryptocurrency technology has been introduced in areas that have traditionally been widely regulated, such as capital raising and money transfer. Politicians and other government officials often try to apply laws that have been developed for decades for the latest technology. The US in each state has a different definition and approach to cryptocurrency transactions. A similar situation is observed in the international arena, where some countries have sought to promote the growth of technology and others have sought to remove technology from their jurisdiction. Therefore, the legal field of law requires in-depth research and analysis on virtual currency transactions, the development and implementation of a new cryptocurrency exchange rate verification mechanism that is similar to those existing for traditional financial processes.
The aim research (1) to know local financial performance with ratio of fiscal decentralization degree, local financial independent, effectiveness of PAD, local finance efficiencey and growth PAD regencies/municipalities in South Borneo province 2013-2017, (2) to know business sector which contributed in PDRB. Technical analysis data is descriptif analysis. The result research showed : by average fiscal decentralization degree ratio 9 regencies still very less and 4 regencies/cities less, 7 regencies low, average local financial independence 4 regencies still very low, 7 regencies low and 2 municipalities enough independence, average effectivene PAD ratio almost all of regencies/municipalities very effective except Banjarmasin municipality are effective, average local financial efficiency ratio 9 regencies/municipalities less effecient and 2 regencies enough efficient, while Banjarbaru municipalities inefficient, growth PAD ratio is positive. Keywords: fiscal decentralization degree ratio, local financial independence ratio, effectiveness of PAD ratio, local financial efficiency ratio, PAD growth ratio.
The article is devoted to the problems of qualification of various types of theft of cryptocurrency, theft of funds committed using cryptocurrency. The article deals with crimes related to the illegal sale of drugs for cryptocurrency and raises the question of the absence in the act of the offense under article 1741 of the Criminal code of the Russian Federation. The author studies the concepts of cryptocurrency and property within the framework of existing scientific opinions and analyzes the versatile judicial practice, which, in particular, tends to classify cryptocurrencies as types of property. The goals and objectives of the study are to determine the range of features and properties of the objects of crimes committed with the use of cryptocurrency, as well as committed against the cryptocurrency as an object of infringement. In the preparation of the article, mainly formal logical methods were used, as a result of which the author analyzes social and legal phenomena. The author concludes that the main feature of the evaluation of the object of crimes in sphere of circulation of cryptocurrency, is the presence of his property and cost characteristics, the possibility of determining the damage for the proper qualification of the offense. It is concluded that cryptocurrency may be the subject of corruption offenses on the basis of scientifically substantiated opinions about the presence of the paid nature of the benefit provided by the cryptocurrency. It is argued that the actions associated with the sale of narcotic drugs and psychotropic substances for cryptocurrency and subsequent actions to transfer cryptocurrency to Fiat money do not form part of the crime providing for liability for the legalization of proceeds from crime.
The use of citizens` and legal entities` personal information is crucial for the protection of human rights at the current stage of society and information technology development. On the one hand, a high-quality system of processing and using this information can increase the level of citizen participation in government-making processes and assist on creating a human-centric approach in public administration, when the state will have all the necessary information to serve citizens (providing of all administrative services online, use of analytics to improve infrastructure, etc.). On the other hand, misuse and unauthorized access to personal data can lead to violations of citizens' rights, corruption and excessive bureaucracy in administrative procedures.At the same time, approaches to the protection of personal data should be not formal, but purely practical. The state policy should be based on the solution of real problems, which often require a complete revision of the systematic approaches, in this case the infrastructure of the state registers.Modern information technologies make it possible to implement large-scale changes in the business processes of collecting, storing and processing personal data of citizens. Moreover, such approaches make it possible to reduce bureaucratic burdens and minimize corruption risks.Distributed registry technology is a popular solution for improving the performance of government processes and enhancing eGovernment in the country. However, its application requires a proper assessment of the problem and its origins, as well as the outcomes that should be achieved
The stability and economy of the electronic vehicle distribution network system is increasingly important as the number of electric vehicles in use continues to rise. An electric vehicle (EV) and Internet of things (IoT) charge scheduling method is proposed in this paper which uses smart contract in the distribution network (DN) with uncertain renewable energy output. Based on user charging demand and power grid load level, this paper explores peak load shifting, guiding EV charging options by electricity price to change the demand response of each node, thereby regulating the DN power quality. A smart contract is created between the user and the charging station to realize the electricity price renewal in the power flow calculation cycle. This enhances the rationality of electricity price formulation and reduces deviation between the forecast load and the actual load, ensuring the validity of the method to a certain extent. According to the achievement of the smart contracts signed with the charging station, users are given rewards or fines, which reduces the default rate of the user. This decentralized transaction process improves the security and completeness of the transaction. The feasibility of utilizing this method for the distributed power grid is verified through simulation on a 34-node test system.
The blockchain data structure maintained via the longest-chain rule—popularized by Bitcoin—is a powerful algorithmic tool for consensus algorithms. Such algorithms achieve consistency for blocks in the chain as a function of their depth from the end of the chain. While the analysis of Bitcoin guarantees consistency with error 2−k for blocks of depth O(k), the state-of-the-art of proof-of-stake (PoS) blockchains suffers from a quadratic dependence on k: these protocols, exemplified by Ouroboros (Crypto 2017), Ouroboros Praos (Eurocrypt 2018) and Sleepy Consensus (Asiacrypt 2017), can only establish that depth Θ(k2) is sufficient. Whether this quadratic gap is an intrinsic limitation of PoS—due to issues such as the nothing-at-stake problem—has been an urgent open question, as deployed PoS blockchains further rely on consistency for protocol correctnes. We give an axiomatic theory of blockchain dynamics that permits rigorous reasoning about the longest-chain rule and achieve, in broad generality, Θ(k) dependence on depth in order to achieve consistency error 2−k In particular, for the first time we show that PoS protocols can match proof-of-work protocols for linear consistency. We analyze the associated stochastic process, give a recursive relation for the critical functionals of this process, and derive tail bounds in both i.i.d. and martingale settings via associated generating functions.
Jörg Weking, Michael Mandalenakis, Andreas Hein, Sebastian Hermes · 6 authors
Abstract Blockchain technology enables new ways of organizing economic activities, reduces costs and time associated with intermediaries, and strengthens the trust in an ecosystem of actors. The impact of this seminal technology is reflected by an upcoming research stream and various firms that examine the potential uses of blockchain technology. While there are promising use cases of this new technology, research and practice are still in their infancy about altering existing and creating new business models. We develop a taxonomy of blockchain business models based on 99 blockchain ventures to explore the impact of blockchain technology on business models. As a result, we identify five archetypal patterns, which enhance our understanding of how blockchain technology affects existing and creates new business models. We propose to use these results to discover further patterns fueled by blockchain technology and illustrate how firms can use blockchain technology to innovate their business models.
Ángeles López Cabarcos, Ada M. Pérez-Pico, Juan Piñeiro Chousa, Aleksandar Šević
Bitcoin is the cryptocurrency with the largest market capitalization, and many studies have examined its role in financial markets. In this manuscript, we contribute to the extant body of knowledge by analyzing the Bitcoin behavior and the effect that investor sentiment, S&P 500 returns, and VIX returns have on Bitcoin volatility using GARCH and EGARCH models. The results suggest that Bitcoin volatility is more unstable in speculative periods. In stable periods, S&P 500 returns, VIX returns, and sentiment influence Bitcoin volatility.
In recent years, the emergence of blockchain technology (BT) has become a unique, most disruptive, and trending technology. The decentralized database in BT emphasizes data security and privacy. Also, the consensus mechanism in it makes sure that data is secured and legitimate. Still, it raises new security issues such as majority attack and double-spending. To handle the aforementioned issues, data analytics is required on blockchain based secure data. Analytics on these data raises the importance of arisen technology Machine Learning (ML). ML involves the rational amount of data to make precise decisions. Data reliability and its sharing are very crucial in ML to improve the accuracy of results. The combination of these two technologies (ML and BT) can provide highly precise results. In this paper, we present a detailed study on ML adoption for making BT-based smart applications more resilient against attacks. There are various traditional ML techniques, for instance, Support Vector Machines (SVM), clustering, bagging, and Deep Learning (DL) algorithms such as Convolutional Neural Network (CNN) and Long short-term memory (LSTM) can be used to analyse the attacks on a blockchain-based network. Further, we include how both the technologies can be applied in several smart applications such as Unmanned Aerial Vehicle (UAV), Smart Grid (SG), healthcare, and smart cities. Then, future research issues and challenges are explored. At last, a case study is presented with a conclusion.
Byzantine State Machine Replication (SMR) is a long studied topic that received increasing attention recently with the advent of blockchains as companies are trying to scale them to hundreds of nodes. Byzantine SMRs try to increase throughput by either reducing the latency of consensus instances that they run sequentially or by reducing the number of replicas that send messages to others in order to reduce the network usage. Unfortunately, the former approach makes use of resources in burst whereas the latter requires CPU-intensive authentication mechanisms. In this paper, we propose a new Byzantine SMR called Dispel (Distributed Pipeline) that allows any node to distributively start new consensus instances whenever they detect sufficient resources locally. We evaluate the performance of Dispel within a single datacenter and across up to 380 machines over 3 continents by comparing it against four other SMRs. On 128 nodes, Dispel speeds up HotStuff, the Byzantine fault tolerant SMR being integrated within Facebook's blockchain, by more than 12 times. In addition, we also test Dispel under isolated and correlated failures and show that the Dispel distributed design is more robust than HotStuff. Finally, we evaluate Dispel in a cryptocurrency application with Bitcoin transactions and show that this SMR is not the bottleneck.
With the exponentially scaled World Wide Web, the standard HTTP protocol has started showing its limitations. With the increased amount of data duplication & accidental deletion of files on the Internet, the P2P file system called IPFS completely changes the way files are stored. IPFS is a file storage protocol allowing files to be stored on decentralized systems. In the HTTP client-server protocol, files are downloaded from a single source. With files stored on a decentralized network, IPFS allows packet retrieval from multiple sources, simultaneously saving considerable bandwidth. IPFS uses a content-addressed block storage model with content-addressed hyperlinks. Large amounts of data is addressable with IPFS with the immutable and permanent IPFS links with meta-data stored as Blockchain transactions. This timestamps and secures the data, instead of having to put it on the chain itself. Our paper proposes a model that uses the decentralized file storage system of IPFS, and the integrity preservation properties of the Blockchain, to store and distribute data on the Web.
Guntur Dharma Putra, Volkan Dedeoglu, Salil S. Kanhere, Raja Jurdak
Heterogeneous and dynamic IoT environments require a lightweight, scalable, and trustworthy access control system for protection from unauthorized access and for automated detection of compromised nodes. Recent proposals in IoT access control systems have incorporated blockchain to overcome inherent issues in conventional access control schemes. However, the dynamic interaction of IoT networks remains uncaptured. Here, we develop a blockchain based Trust and Reputation System (TRS) for IoT access control, which progressively evaluates and calculates the trust and reputation score of each participating node to achieve a self-adaptive and trustworthy access control system. Trust and reputation are explicitly incorporated in the attribute-based access control policy, so that different nodes can be assigned to different access right levels, resulting in dynamic access control policies. We implement our proposed architecture in a private Ethereum blockchain comprised of a Docker container network. We benchmark our solution using various performance metrics to highlight its applicability for IoT contexts.
While key negotiation schemes, such as those based on Diffie–Hellman, have been the subject of ongoing research, designing an efficient and security scheme remains challenging. In this paper, we propose a novel key negotiation scheme based on blockchain, which can be deployed in blockchain-enabled contexts such as data sharing or facilitating electric transactions between vehicles (e.g., unmanned vehicles). We propose three candidates for flexible selection, namely, key exchanges via transaction currency values through value channels (such as the amount in transactions), automated key exchanges through static scripts,and dynamic scripts, which can not only guarantee key availability with timeliness but also defend against MITM (man-in-the-middle) attacks, packet-dropping attacks, and decryption failure attacks.
Le criptovalute sono valute digitali basate sulla crittografia. A differenza delle tradizionali valute legali emesse da sistemi bancari centralizzati, le criptovalute sono decentralizzate e mantenute attraverso meccanismi di consenso distribuito. Nel novembre 2008 Satoshi Nakamoto ha introdotto la prima criptovaluta veramente funzionale: il Bitcoin. Dopo alcuni anni passati nell’ombra, Bitcoin guadagnò rapidamente notorietà, creando un'economia da miliardi di dollari. Sull’onda del successo di Bitcoin il mercato ha visto nascere diverse altre criptovalute. A settembre 2019 si sono registrate più di 2500 criptovalute attive per un mercato di oltre 250 miliardi di Dollari e quasi 50 miliardi di Dollari di volume giornaliero. \nOgni criptovaluta ha un funzionamento peculiare a seconda del proprio obiettivo: alcune si focalizzano sulla limitazione del numero di transazioni, altre sulle prestazioni. Ogni criptovaluta garantisce un certo livello di anonimato dell'utente. Al livello più basso, gli utenti rimangono pseudo-anonimi, ovvero le identità reali del pagatore e del beneficiario rimangono nascoste. I criminali informatici hanno sfruttato l'anonimato offerto dalle criptovalute per perpetrare vari reati, come il riciclaggio di denaro e il finanziamento del terrorismo. \nQuesta tesi indaga sulle implicazioni di sicurezza e privacy delle criptovalute e si compone di tre parti che trattano di recenti ed importanti problematiche relative a: (i) Bitcoin; (ii) Algorand; e (iii) Cryptominers. \nNella prima parte di questa tesi, studiamo due questioni relative al Bitcoin che rivestono un'importanza significativa in questa era di criptovalute. In particolare, ci concentriamo sull’aumento allarmante delle campagne ransomware e sui problemi di privacy relativi alle app di Bitcoin wallet per smartphone. Abbiamo quindi condotto uno studio completo e longitudinale sui recenti attacchi di ransomware e riportando l'impatto economico riscontrato sui pagamenti in Bitcoin. Abbiamo inoltre condotto un lavoro per l’identificazione di attività sensibili sulle app di Bitcoin wallet. Queste app sono comunemente utilizzate per l'invio, la ricezione e il trading di Bitcoin. \nLa seconda parte di questa tesi si concentra su Algorand. Algorand è un protocollo di consenso blockchain democratico che ha il potenziale ridisegnare il futuro della tecnologia blockchain. Questo è il primo studio formale proposto per Algorand. Nella nostra analisi di sicurezza, presentiamo un attacco realmente attuabile su Algorand nonché possibili contromisure. \nNella terza parte di questa tesi, esploriamo il covert cryptomining. La richiesta di cryptomining è aumentata drasticamente con la crescente popolarità delle criptovalute. Parallelamente alle legittime richieste di crittografia, la covert cryptomining è emersa come un mezzo per gli attori malintenzionati per ottenere incentivi finanziari. Le criptovalute come Monero hanno ulteriormente aggravato la situazione, consentendo anche agli utenti ingenui di effettuare cryptomining tramite un'applicazione browser. Considerando la gravità del problema, proponiamo due soluzioni efficienti per rilevare la covert cryptomining in diversi scenari realistici.
Data analytics has captured attention of both researchers as well as business organizations, since a long time now, as the knowledge or information getting analyzed and evolved is priceless in upbringing the business. Blockchain is the latest technology which is getting adopted at a faster rate due to its unique properties. This paper focuses mainly on data models, and some tools used for data analytics being used in blockchain environment. Public blockchain is an open ledger platform which allows to perform data analytics.
While the large-scale Internet of Things (IoT) makes many new applications feasible, like Smart Cities, IoT also brings new concerns on data reliability, security, and privacy. The rapid evolution in blockchain technologies, which relied on a decentralized, immutable and distributed ledger system for transaction data auditing, provides a prospective solution to address the issues in IoT. The blockchain and smart contract enabled security mechanism for IoT applications have attracted increasing interests from both academia and industry. However, integrating cryptocurrency-oriented blockchain technologies into IoT systems meets tremendous challenges on scalability, storage capacity, security, and privacy. Particularly, the performance of blockchain networks significantly relies on the performance of consensus mechanisms, e.g., in terms of data confidentiality, transaction throughput, and network scalability. In this chapter, given an in-depth review of state-of-the-art blockchain networks, the key matrix of designing consensus mechanism for IoT networks are identified in terms of throughput, scalability, and security. To demonstrate a case study on designing scalable, lightweight blockchain protocols for IoT systems, a Microchain framework is introduced and a proof-of-concept prototype is implemented in a physical network environment. The experimental results verify the feasibility of integrating the Microchain into IoT systems.
This position paper presents a synthesis viewpoint of blockchains from two orthogonal perspectives: fault-tolerant distributed systems and game theory. Specifically, we formulate a new game-theoretical problem in the context of blockchains and sketch a closed-form Nash equilibrium to the problem.
Juan Arturo Castañeda-Ayarza, Cíntia Neves, André Frazão Teixeira
No desenvolvimento das tecnologias de informação e internet, as moedas digitais representam uma nova dinâmica tecnológica e monetária. Em 2008, surgiu o Bitcoin, uma moeda virtual em forma de código de computador que se caracteriza por estar livre de vínculos com autoridades monetárias e por não possuir nacionalidade. O crescente interesse no Bitcoin também é encontrado na ciência. Assim, nosso objetivo foi mapear o conhecimento científico desenvolvido acerca do Bitcoin e da tecnologia Blockchain. Através da pesquisa bibliográfica em duas bases de dados, Science Direct e Scielo, mapearam-se, entre 2008 e 2018, 432 publicações, das quais 80% aconteceram entre 2016 e 2018, evidenciando-se o acelerado crescimento da produção científica. Os principais assuntos pesquisados estão relacionados com o mercado de Bitcoin, a segurança e eficiência da tecnologia Blockchain, o mercado ilegal, além das potenciais aplicações em áreas como energia, saúde, economia compartilhada, Big Data e Internet das Coisas.
Initial Coin Offerings (ICOs) and cryptocurrencies are applications of blockchain technology that offer many benefits.ICOs are increasingly used by companies for crowdfunding, allowing startups to find investors.Cryptocurrencies allow cheap, fast and straightforward international money transfers.However, along with such benefits also come risks, like volatility of cryptocurrency rates, abuse by (cyber)criminals, and other risks and uncertainties for investors.Governments across the globe are struggling with the question whether and how to regulate cryptocurrencies and ICOs.The technologies and applications are similar in different jurisdictions, but the responses of legislators, regulators and supervisory authorities widely differ.In this article, we investigate the regulatory responses to cryptocurrencies and ICOs in nine jurisdictions worldwide.The aim of investigating different approaches towards regulating cryptocurrencies and ICOs is to identify different approaches, to make a comparison between jurisdictions, and to identify potential good or best practices.The nine jurisdictions that are compared in this paper are Australia, Belgium, China, Estonia, Japan, Switzerland, The Netherlands, the United States, and the European Union. of cybercrime.Moreover, it should provide some sort of consumer/investor protection and clarity when it comes to tax liability.A legislative and regulatory framework that provides all these aspects will prevent abuse and may enable governments to intervene when issues occur.
This paper aims to examine the relationship between Bitcoin and preeminent financial indicators using Copula-GARCH method. In the study, we use closing prices of Bitcoin and US 10-Year Bond Yield, Gold Spot US Dollar, US Dollar Index, S&P 500, FTSE 100 and NIKKEI 225. To our knowledge, our paper is the first to examine this issue empirically. Analysis results show that there is no strong interdependence between Bitcoin and preeminent financial indicators. These findings provide new information that will benefit policy makers, banks, financial investors, and risk managers in trading activities for both long-term and short-term strategies.