This paper is discusses the problems of the short-term forecasting of financial time series using supervised machine learning (ML) approach. For this goal, we applied several the most powerful methods including Support Vector Machine (SVM), Multilayer Perceptron (MLP), Random Forests (RF) and Stochastic Gradient Boosting Machine (SGBM). As dataset were selected the daily close prices of two stock index: SP 500 and NASDAQ, two the most capitalized cryptocurrencies: Bitcoin (BTC), Ethereum (ETH), and exchange rate of EUR-USD. As features we used only the past price information. To check the efficiency of these models we made out-of-sample forecast for selected time series by using one step ahead technique. The accuracy rates of the forecasted prices by using ML models were calculated. The results verify the applicability of the ML approach for the forecasting of financial time series. The best out of sample accuracy of short-term prediction daily close prices for selected time series obtained by SGBM and MLP in terms of Mean Absolute Percentage Error (MAPE) was within 0.46-3.71 %. Our results are comparable with accuracy obtained by Deep learning approaches.
Current research has led to a rejection of the hypothesis of a normal distribution of financial assets returns. Under these conditions, portfolio variance cannot serve as a good risk measure. In this paper analyzed the daily returns of the most common cryptocurrencies: Bitcoin, Ethereum, XRP, USDT, Bitcoin Cash, Litecoin. It is shown that the asset returns are not normally distributed, but with good precision follow the Cauchy distribution and Laplace distribution. The analytical expressions for risk measure were obtained using the distribution function and the VaR technique. However, the risk assessment of the return obtained on the basis of the Cauchy distribution is twice as high as the risk assessment obtained on the basis of the Laplace distribution. Therefore, the question arises: what distribution law to use to measurement the cryptocurrency risk? The paper shows that the Laplace distribution is the most adequate basis for measuring of cryptocurrencies risk.
Communication security between IoT devices is a major concern in this area, and the blockchain has raised hopes that this concern will be addressed. In the blockchain concept, the majority or even all network nodes check the validity and accuracy of exchanged data before accepting and recording them, whether this data is related to financial transactions or measurements of a sensor or an authentication message. In evaluating the validity of an exchanged data, nodes must reach a consensus in order to perform a special action, in which case the opportunity to enter and record transactions and unreliable interactions with the system is significantly reduced. Recently, in order to share and access management of IoT devices information with distributed attitude a new authentication protocol based on blockchain is proposed and it is claimed that this protocol satisfies user privacy preserving and security. However, in this paper, we show that this protocol has security vulnerabilities against secret disclosure, replay, traceability, and <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mtext>Token</a:mtext> </a:math> reuse attacks with the success probability of 1 and constant complexity of also 1. We also proposed an improved blockchain-based authentication protocol (IBCbAP) that has security properties such as secure access management and anonymity. We implemented IBCbAP using JavaScript programming language and Ethereum local blockchain. We also proved IBCbAP’s security both informally and formally through the Scyther tool. Our comparisons showed that IBCbAP could provide suitable security along with reasonable cost.
U ovom radu će biti predstavljene mogućnosti primene blokčejn tehnologije za podršku sistemima za glasanje i opisan razvoj jednog takvog sistema u vidu aplikacije na Ethereum blokčejn platformi. Aplikacija je implementirana na distribuiran i decentralizovan način kako bi se ispitale prednosti i mane softverskog rešenja ovog tipa.
Efe Bozkir, Shahram Eivazi, Mete Akgün, Enkelejda Kasneci
Eye tracking data collection in the virtual reality context is typically carried out in laboratory settings, which usually limits the number of participants or consumes at least several months of research time. In addition, under laboratory settings, subjects may not behave naturally due to being recorded in an uncomfortable environment. In this work, we propose a proof-of-concept eye tracking data collection protocol and its implementation to collect eye tracking data from remotely located subjects, particularly for virtual reality using Ethereum blockchain and smart contracts. With the proposed protocol, data collectors can collect high quality eye tracking data from a large number of human subjects with heterogeneous socio-demographic characteristics. The quality and the amount of data can be helpful for various tasks in data-driven human-computer interaction and artificial intelligence.
Flash Loan, as an emerging service in the decentralized finance ecosystem, allows traders to request a non-collateral loan as long as the debt is repaid within the transaction. While providing convenience, it brings considerable challenges that Flash Loan allows speculative traders to leverage vulnerability of deployed protocols with vast capital and few risks and responsibilities. Most recently, attackers have gained over $15M profits from Eminence Finance via exploiting Flash Loans to repeatedly swap tokens (i.e., EMN and DAI). To be aware of foxy actions, we should understand what is the behavior running with the Flash Loan by traders. In this work, we propose ThunderStorm, a 3-phase transaction-based analysis framework, to systematically study Flash Loan on the Ethereum. Specifically, ThunderStorm first identifies Flash Loan transactions by applying observed transaction patterns, and then understands the semantics of the transactions based on primitive behaviors, and finally recovers the intentions of transactions according to advanced behaviors. To perform the evaluation, we apply ThunderStorm to existing transactions and investigate 11 well-known platforms. As the result, 22,244 transactions are determined to launch Flash Loan(s), and those Flash Loan transactions are further classified into 7 categories. Lastly, the measurement of financial behaviors based on Flash Loans is present to help further understand and explore the speculative usage of Flash Loan. The evaluation results demonstrate the capability of the proposed system.
Claudia Cristina Bozza, Marcelo Cabús Klötzle, Antônio Carlos Figueiredo Pinto, Paulo Vítor Jordão da Gama Silva
Este trabalho buscou avaliar a existência do efeito de feedback trading para as criptomoedas Bitcoin, Ethereum, Litecoin e Dash usando o modelo VAR proposto por Hasbrouck (1991). Este efeito busca avaliar a utilização de dados passados para tomar decisões futuras, utilizando para tanto, dados de alta frequência, divididos em quatro períodos (dia, hora, minuto e segundo) para captar a existência do efeito de feedback trading nas criptomoedas, visando contribuir para a linha de finanças comportamentais, uma vez que há poucos estudos que avaliam o investimento em mercados digitais seguindo uma perspectiva comportamental. O resultado do modelo indica a existência de feedback trading negativo para todas as criptomoedas nas granularidades de tempo segundo e minuto. O estudo também aponta como resultado do modelo a existência de feedback trading negativo para a granularidade de tempo hora a hora para Litecoin e Dash.
In current healthcare systems, electronic medical records (EMRs) are always located in different hospitals and controlled by a centralized cloud provider. However, it leads to single point of failure as patients being the real owner lose track of their private and sensitive EMRs. Hence, this article aims to build an access control framework based on smart contract, which is built on the top of distributed ledger (blockchain), to secure the sharing of EMRs among different entities involved in the smart healthcare system. For this, we propose four forms of smart contracts for user verification, access authorization, misbehavior detection, and access revocation, respectively. In this framework, considering the block size of ledger and huge amount of patient data, the EMRs are stored in cloud after being encrypted through the cryptographic functions of elliptic curve cryptography (ECC) and Edwards-curve digital signature algorithm (EdDSA), while their corresponding hashes are packed into blockchain. The performance evaluation based on a private Ethereum system is used to verify the efficiency of proposed access control framework in the real-time smart healthcare system.
The reality is that we live in a society where a small group of people thinks they know better than we do and how we should live our lives. They don’t ever seem to realize that the power and wealth they surround themselves with is only possible because of the quiet acquiescence of the majority. They say employment is a record high, but fail to say wages have been going down in real terms for decades. This wall street elites and big head of governments and pharmaceutical businesses constantly keep telling the general population how great everything is but deep down we all know it’s not true as Recent estimates for global poverty are that 8.6 percent of the world, or 736 million people, live in extreme poverty on 1.90 dollars or less a day, according to the World Bank but we know in our bones it’s not true. But it could be and through technology, it will be. As the only answer to political and financial problems that assail us is to step outside the circus. That’s where cryptocurrencies come in, as they offer a secure form of transferring or recording ownership of our assets and the most important part is they function completely independently of governments. Whether you are with or against them cryptocurrencies represent one of the biggest bull markets in the history of finance and it’s the only boom that comes close to the California gold rush. So as a future Muslim Moroccan scientific researcher in the field of Cybersecurity and block-chain technology I couldn’t help but wonder how could we use this technology in my country to revolutionize the banking and Financial sector in it and especially after I learned that Morocco prohibited the use of bitcoin back in 2017. I then found myself asking the following questions: how does cryptocurrency conform to sharia’s Islamic teaching especially in Morocco? And how could the use of cryptocurrencies send shock waves across the Middle East?
The outbreak of the respiratory disease caused by the new coronavirus (COVID-19) has caused the world to face an existential health crisis. To contain the infectious disease, many countries have quarantined their citizens for several weeks to months and even suspended most economic activities. To track the movements of residents, the governments of many states have adopted various novel technologies. Connecting billions of sensors and devices over the Internet, the so-called Internet of Things (IoT), has been used for outbreak control. However, these technologies also pose serious privacy risks and security concerns with regards to data transmission and storage. In this paper, we propose a blockchain-based system to provide the secure management of home quarantine. The privacy and security attributes for various events are based on advanced cryptographic primitives. To demonstrate the application of the system, we provide a case study in an IoT system with a desktop computer, laptop, Raspberry Pi single-board computer, and the Ethereum smart contract platform. The obtained results prove its ability to satisfy security, efficiency, and low-cost requirements.
Superlight clients enable the verification of proof-of-work-based blockchains by checking only a small representative number of block headers instead of all the block headers as done in simplified payment verification (SPV). Such clients can be embedded within other blockchains by implementing them as smart contracts, allowing for cross-chain verification. One such interesting instance is the consumption of Bitcoin data within Ethereum by implementing a Bitcoin superlight client in Solidity. While such theoretical constructions have demonstrated security and efficiency in theory, no practical implementation exists. In this work, we put forth the first practical Solidity implementation of a superlight client which implements the NIPoPoW superblocks protocol. Contrary to previous work, our Solidity smart contract achieves sufficient gas-efficiency to allow a proof and counter-proof to fit within the gas limit of a block, making it practical. We provide extensive experimental measurements for gas consumption. The optimizations that enable gas-efficiency heavily leverage a novel technique which we term hash-and-resubmit, which almost completely eliminates persistent storage requirements, the most expensive operation of smart contracts in terms of gas. Instead, the contract asks contesters to resubmit data and checks their veracity by hashing it. Other optimizations include off-chain manipulation of proofs in order to remove expensive look-up structures, and the usage of an optimistic schema. We show that such techniques can be used to bring down gas costs significantly and may be of independent interest. Lastly, our implementation allows us to calculate concrete cryptoeconomic parameters for the superblocks NIPoPoWs protocol and in particular to make recommendations about the monetary value of the collateral parameters. We provide such parameter recommendations over a variety of liveness settings.
The availability-finality dilemma says that blockchain protocols cannot be both available under dynamic participation and safe under network partition. Snap-and-chat protocols have recently been proposed as a resolution to this dilemma. A snap-and-chat protocol produces an always available ledger containing a finalized prefix ledger which is always safe and catches up with the available ledger whenever network conditions permit. In contrast to existing handcrafted finality gadget based designs like Ethereum 2.0's consensus protocol Gasper, snap-and-chat protocols are constructed as a black-box composition of off-the-shelf BFT and longest chain protocols. In this paper, we consider system aspects of snap-and-chat protocols and show how they can provide two important features: 1) accountability, 2) support of light clients. Through this investigation, a deeper understanding of the strengths and challenges of snap-and-chat protocols is gained.
The building workers sector is one of the most challenging for Human Resources (HR) management. In this work we propose a solution relying on the Blockchain technology and present the design of a Blockchain-Oriented Software system conceived for managing the building workers sector with a focus on workers' safety and guided by sustainable and Agile Methodologies in software design. The proposed approach takes advantage of different features of the Blockchain technology and provides transparency for labour inspectors, grants data integrity and immutability, relies in tamper proof time stamps for any recorded activity, allows the implementation of Smart Contracts where clauses are automatically respected without the need of a trusted control authority, acknowledges the legal requirements in the field, including the possibility of creating the Operational Safety Plans, which construction companies have to provide and finally implements the creation of vacant job positions which workers can find and apply to. In order to achieve these goals we adopt the Blockchain-Oriented Software Engineering (BOSE) methodology to design Blockchain software applications and apply an Agile methodology centered on Blockchain Software development, (called ABCDE) for the design and development of the decentralized application. Such methodology allows to center the software development around the actors of the system in the specific domain, such as Building Workers, Construction Companies, Labour Inspectors and so on. In addition we rely on the software sustainability analysis, based on the five dimensions of sustainability, to evaluate the approach and to avoid mistakes in the system development. We design system elements with specific diagrams and we divided our system in the on-chain and the out-of-chain components. The implementation of the system, done by using Ethereum and the ERC721 standard, allows us to improve some aspect of the design, to know the deployment and usage costs, and to evaluate the effect of the user interface. Finally, we discuss about the effects of our system and its sustainability, and provide a comparison of our system with a similar per aims but centralized system.
Sarad Venugopalan, Ivan Homoliak, Zengpeng Li, Pawel Szalachowski
Voting is a means to agree on a collective decision based on available choices (e.g., candidates), where participants agree to abide by their outcome. To improve some features of e-voting, decentralized blockchain-based solutions can be employed, where the blockchain represents a public bulletin board that in contrast to a centralized bulletin board provides extremely high availability, censorship resistance, and correct code execution. A blockchain ensures that all entities in the voting system have the same view of the actions made by others due to its immutability and append-only features. The existing remote blockchain-based boardroom voting solution called Open Voting Network (OVN) provides the privacy of votes, universal & End-to-End verifiability, and perfect ballot secrecy; however, it supports only two choices and lacks robustness enabling recovery from stalling participants. We present BBB-Voting, an equivalent blockchain-based approach for decentralized voting such as OVN, but in contrast to it, BBB-Voting supports 1-out-of-$k$ choices and provides robustness that enables recovery from stalling participants. We make a cost-optimized implementation using an Ethereum-based environment respecting Ethereum Enterprise Alliance standards, which we compare with OVN and show that our work decreases the costs for voters by 13.5% in normalized gas consumption. Finally, we show how BBB-Voting can be extended to support the number of participants limited only by the expenses paid by the authority and the computing power to obtain the tally.
Large-scale power systems are composed of regional utilities with assets that stream sensor readings in real time. In order to detect cyberattacks, the globally acquired, real-time sensor data needs to be analyzed in a centralized fashion. However, owing to operational constraints, such a centralized sharing mechanism turns out to be a major obstacle. In this article, we propose a blockchain-based decentralized framework for detecting coordinated replay attacks with full privacy of sensor data. We develop a Bayesian inference mechanism employing locally reported attack probabilities that is tailor made for a blockchain framework. We compare our framework to a traditional decentralized algorithm based on the broadcast gossip framework both theoretically as well as empirically. With the help of experiments on a private Ethereum blockchain, we show that our approach achieves good detection quality and significantly outperforms gossip-driven approaches in terms of accuracy, timeliness, and scalability.
The need to protect sensitive data is growing, and environmental data are now considered sensitive. The application of last-generation procedures such as blockchains coupled with the implementation of new air quality monitoring technology allows the data protection and validation. In this work, the use of a blockchain applied to air pollution data is proposed. A blockchain procedure has been designed and tested. An Internet of Things (IoT)-based sensor network provides air quality data in terms of particulate matter of two different diameters, particulate matter (PM)10 and PM2.5, volatile organic compounds (VOC), and nitrogen dioxide (NO2) concentrations. The dataset also includes meteorological parameters and vehicular traffic information. This work foresees that the data, recovered from traditional Not Structured Query Language (NoSQL) database, and organized according to some specifications, are sent to the Ethereum blockchain daily automatically and with the possibility to choose the period of interest manually. There was also the development of a transaction management and recovery system aimed at retrieving data, formatting it according to the specifications and organizing it into files of various formats. The blockchain procedure has therefore been used to track data provided by air quality monitoring networks unequivocally.
Kazi Masudul Alam, J.M. Ashfiqur Rahman, Anisha Tasnim, Aysha Akther
Bangladesh is a small country with a large population. Its increasingly developing economy further makes land a lucrative source of fixed capital. On the other hand, land titling is a cumbersome and lengthy process, where different government bodies process different sets of documents, and bureaucratic loopholes encourage fraudulent activities by organized people. As a result, the current model suffers from good governance. In this paper, we propose a Blockchain-based solution that offers data synchronization and transparency, ease of access, immutable records management, a faster and cheaper solution. Considering the technological knowledge and capacity of the people and the government, we introduced a phase by phase Blockchain adoption model that starts with a public Blockchain ledger and later gradually incorporates two levels of Hybrid Blockchain. We provide detailed smart contracts design of the public Blockchain and implement a prototype system using Ethereum. Our experimental setup uses local and live Ethereum test networks to demonstrate the efficacy of the proposed system. Our analysis shows that the proposed model reduces the number of required travels, the overall cost of information processing as well as provide easy access to vital information. As a result, Blockchain adoption can improve the land title digitization effort of Bangladesh.
To mitigate the scalability problem of decentralized cryptocurrencies such as Bitcoin and Ethereum, the payment channel, which allows two parties to perform secure coin transfers without involving the blockchain, has been proposed. The payment channel increases the transaction throughput of two parties to a level that is only limited by their network bandwidth. Recent proposals focus on extending the two-party payment channel to the N-party payment hub. Unfortunately, none of them can achieve efficiency, flexibility in the absence of a trusted third-party. In this paper, we propose Garou, a secure N-party payment hub that allows multiple parties to perform secure off-chain coin transfers. Except in the case of disputes, participants within the payment hub can make concurrent and direct coin transfers with each other without the involvement of the blockchain or any third-party intermediaries. This allows Garou to achieve both high-performance and flexibility. If all participants keep online, Garou guarantees all honest users’ balance security against strong adversarial capabilities. To demonstrate the feasibility of the Garou protocol, we develop a proof of concept prototype for the Ethereum network. Experimental evaluations show that, with 300 participants and without disputes, that the maximum transaction throughput of Garou is$20{ \times }$higher than that of state-of-the-art payment hubs.
Increased adoption of the Internet of Things (IoT) in multiple domain areas continuously increases the volume of data and transactions from the IoT devices. The IoT systems are vulnerable to more attacks because of increased adoptions and technology adoptions. Protecting the data and providing security to the data and transactions is one of the critical issues for the effective quality of service (QoS) in the IoT environments. An adaptable IoT framework is proposed based on the research approach of 'ADOPT' that leverages the blockchain technology and features considering security as one of the QoS parameters. In the proposed model of a three-layer IoT architecture with an application layer, network layer, and perception layer, the blockchain features are adopted for the resource-constrained IoT environment. In the perception layer, the model uses a local and temporary memory to maintain the local chain, which is managed based on the memory size and time constraints. The application layer nodes manage the synchronization of the data from the corresponding local chain at the edge node. The implementation of the proposed model uses Ethereum, an open-source public blockchain, and using mobile devices as an edge node. The results are verified for security factors like access, authorizations, confidentiality, and computing resources.
The purpose of this paper is to discuss the determinants of G7, and Chinese stock market returns during the COVID-19 outbreak. We find that Bitcoin and Ethereum can generate benefits from portfolio diversification and hedging strategies for G7 financial investors in early 2020. Our result reveals that Gold is neither hedge nor haven during the COVID-19 pandemic. In addition, the results indicated that the expected volatility of the US stock market has no effect on the Japanese and Chinese financial markets. Finally, our results suggest that the growth rate of confirmed COVID-19 cases and deaths has an impact only on the US stock market.
A product of the 21st century, crypto-currency is a digital representation of a value that can be digitally traded and functions as a medium of exchange, a unit of account or store of value. Safety, simplicity, affordability, reachability, and transparency are advantages however, challenges such as fraud, complexity, money laundering plague Bitcoin, Lite coin, Dodge coin, Amazon coin,ethereum coin, Nemcoin, Libra, DC/EP coin.