Shreya Joshi, Ms Bhavyaa, Suhani Gupta, Lalita Luthra
Blockchain is considered to be a disruptive core technology. Although many researchers have realized the importance of blockchain, but the research of it is still emerging. It is the record-keeping technology behind bitcoin and is one of the hottest and fastest growing skills in the IT sector today. It serves as an immutable ledger which allows transactions to take place in a decentralized man Blockchain-based applications are rising up, covering numerous fields including finance, healthcare, product management, Internet of Things (IoT), and many more. However, there are still some challenges of blockchain technology such as scalability and security problems which need to be overcome. This paper comprises of a comprehensive study of Blockchain technology. We have included here a deep dive into how blockchains work, its architecture, consensus and various applications. Furthermore, technical challenges are briefly listed.
The world is currently witnessing dangerous shifts in the epidemic of emerging SARS-CoV-2, the causative agent of (COVID-19) coronavirus. The infection, and death numbers reported by World Health Organization (WHO) about this epidemic forecasts an increasing threats to the lives of people and the economics of countries. The greatest challenge that most governments are currently suffering from is the lack of a precise mechanism to detect unknown infected cases and predict the infection risk of COVID-19 virus. In response to mitigate this challenge, this study proposes a novel innovative approach for mitigating big challenges of (COVID-19) coronavirus propagation and contagion. This study propose a blockchain-based framework which investigate the possibility of utilizing peer-to peer, time stamping, and decentralized storage advantages of blockchain to build a new system for verifying and detecting the unknown infected cases of COVID-19 virus. Moreover, the proposed framework will enable the citizens to predict the infection risk of COVID-19 virus within conglomerates of people or within public places through a novel design of P2P-Mobile Application. The proposed approach is forecasted to produce an effective system able to support governments, health authorities, and citizens to take critical decision regarding the infection detection, infection prediction, and infection avoidance. The framework is currently being developed and implemented as a new system consists of four components, Infection Verifier Subsystem, Blockchain platform, P2P-Mobile Application, and Mass-Surveillance System. This four components work together for detecting the unknown infected cases and predicting and estimating the infection Risk of Corona Virus (COVID-19).
Large scale cryptocurrencies require the participation of millions of participants and support economic activity of billions of dollars, which has led to new lines of work in binary Byzantine Agreement (BBA) and consensus. The new work aims to achieve communication-efficiency---given such a large $n$, not everyone can speak during the protocol. Several protocols have achieved consensus with communication-efficiency, even under an adaptive adversary, but they require additional strong assumptions---proof-of-work, memory-erasure, etc. All of these protocols use multicast: every honest replica multicasts messages to all other replicas. Under this model, we provide a new communication-efficient consensus protocol using Verifiable Delay Functions (VDFs) that is secure against adaptive adversaries and does not require the same strong assumptions present in other protocols. A natural question is whether we can extend the synchronous protocols to the partially synchronous setting---in this work, we show that using multicast, we cannot. Furthermore, we cannot achieve always safe communication-efficient protocols (that maintain safety with probability 1) even in the synchronous setting against a static adversary when honest replicas only choose to multicast its messages. Considering these impossibility results, we describe a new communication-efficient BBA protocol in a modified partially synchronous network model which is secure against adaptive adversaries with high probability.
Dimitri Kamenski, Arash Shaghaghi, Matthew Warren, Salil S. Kanhere
We focus on the problem of botnet orchestration and discuss how attackers can leverage decentralised technologies to dynamically control botnets with the goal of having botnets that are resilient against hostile takeovers. We cover critical elements of the Bitcoin blockchain and its usage for `floating command and control servers'. We further discuss how blockchain-based botnets can be built and include a detailed discussion of our implementation. We also showcase how specific Bitcoin APIs can be used in order to write extraneous data to the blockchain. Finally, while in this paper, we use Bitcoin to build our resilient botnet proof of concept, the threat is not limited to Bitcoin blockchain and can be generalized.
Yuris Mulya Saputra, Diep N. Nguyen, Dinh Thai Hoang, Thang X. Vu · 6 authors
In this paper, we propose a novel energy-efficient framework for an electric vehicle (EV) network using a contract theoretic-based economic model to maximize the profits of charging stations (CSs) and improve the social welfare of the network. Specifically, we first introduce CS-based and CS clustering-based decentralized federated energy learning (DFEL) approaches which enable the CSs to train their own energy transactions locally to predict energy demands. In this way, each CS can exchange its learned model with other CSs to improve prediction accuracy without revealing actual datasets and reduce communication overhead among the CSs. Based on the energy demand prediction, we then design a multi-principal one-agent (MPOA) contract-based method. In particular, we formulate the CSs' utility maximization as a non-collaborative energy contract problem in which each CS maximizes its utility under common constraints from the smart grid provider (SGP) and other CSs' contracts. Then, we prove the existence of an equilibrium contract solution for all the CSs and develop an iterative algorithm at the SGP to find the equilibrium. Through simulation results using the dataset of CSs' transactions in Dundee city, the United Kingdom between 2017 and 2018, we demonstrate that our proposed method can achieve the energy demand prediction accuracy improvement up to 24.63% and lessen communication overhead by 96.3% compared with other machine learning algorithms. Furthermore, our proposed method can outperform non-contract-based economic models by 35% and 36% in terms of the CSs' utilities and social welfare of the network, respectively.
Zahra Foroozandeh, Sérgio Ramos, João Soares, Fernando Lezama · 7 authors
Efficient alternatives in energy production and consumption are constantly being investigated and conducted by increasingly strict policies. Buildings have a significant influence on electricity consumption, and their management may contribute to the sustainability of the electricity sector. Additionally, with growing incentives in the distributed generation (DG) and electric vehicle (EV) industries, it is believed that smart buildings (SBs) can play a key role in sustainability goals. In this work, an energy management system is developed to reduce the power demands of a residential building, considering the flexibility of the contracted power of each apartment. In order to balance the demand and supply, the electrical power provided by the external grid is supplemented by microgrids such as battery energy storage systems (BESS), EVs, and photovoltaic (PV) generation panels. Here, a mixed binary linear programming formulation (MBLP) is proposed to optimize the scheduling of the EVs charge and discharge processes and also those of BESS, in which the binary decision variables represent the charging and discharging of EVs/BESS in each period. In order to show the efficiency of the model, a case study involving three scenarios and an economic analysis are considered. The results point to a 65% reduction in peak load consumption supplied by an external power grid and a 28.4% reduction in electricity consumption costs.
Badr Eddine Sabir, Mohamed Youssfi, Omar Bouattane, Hakim Allali
The Internet of Things (IoT) is becoming an indispensable part of the actual Internet and continues to extend deeper into the daily lives of people, offering distributed and critical services. Mobile agents are widely used in the context of IoT and due to the possibility of transmitting their execution status from one device to another in an IoT network, they offer many advantages such as reducing network load, encapsulating protocols, exceeding network latency, etc. Also, Blockchain Technology is growing rapidly allowing for the addition of an approved security layer in many areas. Security issues related to mobile agent migration can be resolved with the use of Blockchain. This paper aims to demonstrate how Blockchain Technology can be used to secure mobile agents in the context of the IoT using Ethereum and a Smart Contract. The transactions within the Blockchain are used to detect the malevolent mobile agents that could infiltrate the IoT systems. The proposed model aims to provide a secure migration of mobile agents to ensure security and protect the IoT applications against malevolent agents. The case of a smart home with multiple applications is applied to verify the proposed solution. The model presented in this paper could be extended to a wider selection of IoT systems outside of the smart home.
Measurement of the financial performance of local governments can show the financial condition of local governments and the ability of the region to explore and manage the existing sources of funds. A good regional financial performance can be seen from its effectiveness in exploring regional potentials, lower dependency on the central government, and a larger portion of PAD to finance regional development. This study seeks to measure the financial performance of the District-City Government in West Java by using a regional financial ratio measurement tool, which consists of the Fiscal Decentralization Ratio, the Regional Government Financial Dependency Ratio, the PAD Effectiveness Ratio, and the Capital Expenditure Ratio. The results of the measurement of the Fiscal Decentralization Ratio concluded that the financial capacity of the Regency-City Government in West Java is still classified as "LESS". The measurement results of the Regional Government Financial Dependency Ratio concluded that there were no local governments whose financial dependence on transfer funds falls into the "LOW" category. The results of the measurement of the PAD Effectiveness Ratio concluded that the majority of local governments in West Java had been effective and very effective in realizing the PAD target. And the results of the Capital Expenditure Ratio measurement concluded that there had been efforts from the District-City Government in West Java to maximize Capital Expenditures. This study has several limitations. Subsequent research can add the scope of testing or assessment to be more comprehensive, for example by conducting tests or studies on the determinants of the financial performance of local governments or the impact resulting from the factual conditions of the financial performance of local governments.
We propose SessionC#, a lightweight session typed library for safe concurrent/distributed programming. The key features are (1) the improved fluent interface which enables writing communication in chained method calls, by exploiting C#'s out variables, and (2) amalgamation of session delegation with async/await, which materialises session cancellation in a limited form, which we call session intervention. We show the effectiveness of our proposal via a Bitcoin miner application.
Los desarrollos tecnológicos inciden en la forma en que tiene lugar el desenvolvimiento de las relaciones humanas a través del uso de los instrumentos jurídicos. Internet y los sistemas informáticos permiten la creación, almacenamiento, recuperación y difusión de documentos a través de códigos digitales. Así, los documentos se desmaterializan para digitalizarse. Por ello, el artículo pretende realizar una aproximación a los conceptos de blockchain y smart contract, y luego abordar algunas posibles vinculaciones e incidencias respecto de las funciones notariales.
 ABSTRACT:
 Technological developments affect the development of human relationships through the use of legal instruments. Internet and computer systems allow the creation, storage, retrieval and dissemination of documents through digital codes. Thus, documents are dematerialized to be digitized. Therefore, the article aims to make an approach to the concepts of blockchain and smart contract, and then present some possible impacts regarding notarial functions.
With the proliferation of blockchain projects and applications, cryptocurrency exchanges, which provides exchange services among different types of cryptocurrencies, become pivotal platforms that allow customers to trade digital assets on different blockchains. Because of the anonymity and trustlessness nature of cryptocurrency, one major challenge of crypto-exchanges is asset safety, and all-time amount hacked from crypto-exchanges until 2018 is over $1.5 billion even with carefully maintained secure trading systems. The most critical vulnerability of crypto-exchanges is from the so-called hot wallet, which is used to store a certain portion of the total asset online of an exchange and programmatically sign transactions when a withdraw happens. It is important to develop network security mechanisms. However, the fact is that there is no guarantee that the system can defend all attacks. Thus, accurately controlling the available assets in the hot wallets becomes the key to minimize the risk of running an exchange. In this paper, we propose Shoreline, a deep learning-based threshold estimation framework that estimates the optimal threshold of hot wallets from historical wallet activities and dynamic trading networks.
With the proliferation of blockchain projects and applications, cryptocurrency exchanges, which provides exchange services among different types of cryptocurrencies, become pivotal platforms that allow customers to trade digital assets on different blockchains. Because of the anonymity and trustlessness nature of cryptocurrency, one major challenge of crypto-exchanges is asset safety, and all-time amount hacked from crypto-exchanges until 2018 is over $1.5 billion even with carefully maintained secure trading systems. The most critical vulnerability of crypto-exchanges is from the so-called hot wallet, which is used to store a certain portion of the total asset of an exchange and programmatically sign transactions when a withdraw happens. Whenever hackers managed to gain control over the computing infrastructure of the exchange, they usually immediately obtain all the assets in the hot wallet. It is important to develop network security mechanisms. However, the fact is that there is no guarantee that the system can defend all attacks. Thus, accurately controlling the available assets in the hot wallets becomes the key to minimize the risk of running an exchange. However, determining such optimal threshold remains a challenging task because of the complicated dynamics inside exchanges. In this paper, we propose Shoreline, a deep learning-based threshold estimation framework that estimates the optimal threshold of hot wallets from historical wallet activities and dynamic trading networks. We conduct extensive empirical studies on the real trading data from a trading platform and demonstrate the effectiveness of the proposed approach.
Tadas Limba, Andrejus Novikovas, Andrius Stankevičius, Antanas Andrulevičius · 5 authors
Two mainstream topics have been widely discussed over the past few years: ways to reduce the human impact on nature and the way that the industrial revolution 4.0 changes industries. The aim of this research topic is to analyse the positive and negative factors of big data implementation in the sector of cryptocurrency (as part of the industrial revolution 4.0) and in the sector of municipal waste management. The analysis reveals the differences and similarities between the cryptocurrency and municipal waste management sectors in the context of big data. The findings are significant for the estimation of the technological development of digitalized and non-digitalized sectors.
Francesco Buccafurri, Vincenzo De Angelis, Roberto Nardone
The Internet of Things is constantly capturing interest from modern applications, changing our everyday life and empowering industrial applications. Interaction and the collaboration among smart devices offer new challenges to security since they conflict with economic and energy consumption requirement constraints. On the other hand, the lack of security measures could negatively impact the concrete adoption of this paradigm. This paper focuses on the Message Queuing Telemetry Transport (MQTT) protocol, widely adopted in the Internet of Things. This protocol does not implement natively secure authentication mechanisms, which are demanded to developers. Hence, this paper proposes a novel OTP (one-time password)-authentication schema for MQTT, which uses the Ethereum blockchain to implement a second-factor out-of-band channel. The proposal enables the authentication of both local and remote devices preserving user privacy and guaranteeing trust and accountability via Ethereum smart contracts.
Roy Cerqueti, Massimiliano Giacalone, Raffaele Mattera
Recently, cryptocurrencies have attracted a growing interest from investors, practitioners and researchers. Nevertheless, few studies have focused on the predictability of them. In this paper we propose a new and comprehensive study about cryptocurrency market, evaluating the forecasting performance for three of the most important cryptocurrencies (Bitcoin, Ethereum and Litecoin) in terms of market capitalization. At this aim, we consider non-Gaussian GARCH volatility models, which form a class of stochastic recursive systems commonly adopted for financial predictions. Results show that the best specification and forecasting accuracy are achieved under the Skewed Generalized Error Distribution when Bitcoin/USD and Litecoin/USD exchange rates are considered, while the best performances are obtained for skewed Distribution in the case of Ethereum/USD exchange rate. The obtain findings state the effectiveness -- in terms of prediction performance -- of relaxing the normality assumption and considering skewed distributions.
Traditional IT security mechanisms are generally not well-suited for IoT devices, where processing and network connectivity should be kept at minimal. Consequently, IoT devices have been recently identified as an easy target for cyber-attacks, like for example on the Mirai botnet Distributed Denial of Service attacks in 2016, where various devices were hacked into and taken over. Different solutions have been developed aiming at guaranteeing the security at both the devices application layer and the network layers. Few succeeded to deliver the flexibility necessary for IoT devices. Even fewer have implemented an effective threats detection system, and just a handful have realised all the previous in a fully decentralised fashion, including this one. This Distributed Ledger Technology (DLT) attestation system is maintained and supported by most, or all, IoT devices because it is based on a light-weight DLT protocol. It comprises of a system for authorisation and authentication for the individual devices as well as includes an anomalies detection system based on smart contracts. A demonstration was built to support a Smart City use case. The objective is to guarantee, in a decentralised manner, the security of low computational power devices executing the sensing function and their connectivity, and therefore the correct functioning of the system. On the demonstrator, the system was ran using DLT supported by the sensors connectivity bridge (built using Raspberry Pi’s). The system proved to be rapid to develop, flexible with regards to systems changes and resilient to attacks to both individual IoT devices and to the DLT.
The `Black Thursday' crisis in cryptocurrency markets demonstrated deleveraging risks in over-collateralized non-custodial stablecoins. We develop a stochastic model that helps explain deleveraging crises in these over-collateralized systems. In our model, the stablecoin supply is decided by speculators who optimize the profitability of a leveraged position while incorporating the forward-looking cost of collateral liquidations, which involves the endogenous price of the stablecoin. We formally characterize regimes that are interpreted as stable and unstable for the stablecoin. We prove bounds on quadratic variation and the probability of large deviations in the stable domain and we demonstrate distinctly greater price variance in the unstable domain. We identify a deflationary deleveraging spiral by means of a submartingale. These deleveraging spirals, which resemble short squeezes, lead to faster collateral drawdown (and potential shortfalls) and are accompanied by higher price variance, as experienced on Black Thursday. We conclude by discussing non-custodial ways in which the issues raised in this paper can be mitigated.
Metaheuristic search strategies have proven their effectiveness against man-made solutions in various contexts. They are generally effective in local search area exploitation, and their overall performance is largely impacted by the balance between exploration and exploitation. Recent developments in parallel local search explore methods to take advantage of the efficient local exploitation of searches and reach impressive results. This however restricts the scaling potential to nodes within a private, trusted computer cluster. In this research we propose a novel blockchain protocol that allows parallel local search to scale to untrusted and anonymous computational nodes. The protocol introduces publicly verifiable performance evaluation of the local optima reported by each node, creating a competitive environment between the local searches. That is strengthened with economical stimuli for producing good solutions, that provide coordination between the nodes, as every node tries to explore different sections of the search space to beat their competition.
Federated learning has been widely studied and applied to various scenarios, such as financial credit, medical identification, and so on. Under these settings, federated learning protects users from exposing their private data, while cooperatively training a shared machine learning algorithm model (i.e., the global model) for a variety of realworld applications. The only data exchanged is the gradient of the model or the updated model (i.e., the local model update). However, the security of federated learning is increasingly being questioned, due to the malicious clients or central servers' constant attack on the global model or user privacy data. To address these security issues, we propose a decentralized federated learning framework based on blockchain, that is, a Block-chain-based Federated Learning framework with Committee consensus (BFLC). Without a centralized server, the framework uses blockchain for the global model storage and the local model update exchange. To enable the proposed BFLC, we also devise an innovative committee consensus mechanism, which can effectively reduce the amount of consensus computing and reduce malicious attacks. We then discuss the scalability of BFLC, including theoretical security, storage optimization, and incentives. Finally, based on a FISCO blockchain system, we perform experiments using an AlexNet model on several frameworks with a real-world dataset FEMNIST. The experimental results demonstrate the effectiveness and security of the BFLC framework.
Apr 2, 2020·CEUR Workshop Proceedings, Vol-2588: Proceedings of the International Workshop on Conflict Management in Global Information Networks (CMiGIN 2019)
Наталія Краус, Наталія Олександрівна Андрусяк, Аліна Савченко, Maksim Iavich
Pursuing the purpose of effective functioning in today's conditions, the business is forced to transform rapidly, to modernize at all levels. The world is changing, erasing the limits of its certainty. Companies need quality trans- formations and strategies that are effective in the face of rapid change towards "deep" digitization. Massive corporate management systems increasingly need the flexibility to keep pace with change. And companies with an innovative cul- ture are more in need of creative tasks than implementing detailed regulations. In the post-industrial time of digital economy, issues related to the development of the information sphere, the media and communications, the usage of modern information systems to develop the economy and stabilize social development as a whole, come first. The basic principles of practical application of Block- chain are investigated in the work. The stages of development of Blockchain technology, the stages of development of Blockchain technologies by time, the application of distributed registry technology in Blockchain applications, the principles of construction and operation of Blockchain have been specified. The benefits of using NEM for business are substantiated and the components of Proxima X technology, protocols and service layers, on-line and off-line proto- cols, decentralized applications are exposed.
Vinicius Branco, Bruno Lippert, Roben Castagna Lunardi, Henry C. Nunes · 9 authors
Após a introdução do Bitcoin, a tecnologia de \textit{blockchain} evoluiu como uma solução para fornecer integridade, não repúdio e disponibilidade de dados para diferentes sistemas. Cenários sensíveis a dados, como Health Care, também podem se beneficiar dessas propriedades da blockchain. Assim, diferentes propostas, tanto da Academia quanto da Indústria, foram implantadas para permitir a adoção de blockchain em aplicativos de assistência médica. No entanto, existem poucas discussões sobre métodos de incentivo para ajudar a motivar novos usuários a adotar sistemas de saúde. Além disso, pouco se discute sobre o desempenho para executar códigos em blockchains públicos e privados. Para resolver esses problemas, este trabalho apresenta uma avaliação do TokenHealth, um aplicativo para monitoramento colaborativo de práticas de saúde com gamificação e incentivos baseados em tokens, em diferentes redes da Ethereum. A solução proposta é implementada por meio de smart contracts usando a linguagem Solidity e executada em máquinas virtuais da Ethereum (EVM). Avaliamos o desempenho da rede de teste Ropsten e de uma instância privada da Ethereum. Os resultados preliminares mostram que a execução de smart contracts leva menos de um minuto para um ciclo completo de diferentes smart contracts. Além disso, apresentamos uma discussão sobre os custos do uso de uma instância privada e da rede principal pública do Ethereum.
Anwar Hasan Abdullah Othman, Syed Musa Alhabshi, Salina Kassim, Adam Abdullah · 5 authors
Purpose This study uses the autoregressive distributed lag model (ARDL) econometric approach to investigate empirically the effects of cryptocurrencies, the gold standard and traditional fiat money on global income inequality measured based on the Gini coefficient, and various ratios of income inequality distribution such as top 1 per cent, top 10 per cent, top 40 per cent and top 50 per cent. Design/methodology/approach The study uses the ARDL econometric approach. Findings The findings indicated that cryptocurrency and gold standard monetary systems contributed significantly to reducing global inequality of income and wealth distribution. Conversely, the traditional fiat money system contributes positively to global income and wealth inequality while also contributing significantly to their fluctuation. Practical implications This suggests that the fiat monetary system results in the coercive redistribution of income and wealth if governments pursue a social welfare policy. They must resolve this conflict between the current fiat monetary system and social policy by opting for an alternative monetary system such as cryptocurrency or gold standard. These alternative monetary systems offer the promise of resolving the income and wealth inequality associated with the traditional monetary system which are accompanied with the channels of inflation, lack of financial inclusion and debt creation, and to offer a more sustainable financial system. Originality/value The study recommends that monetary policy must be revisited to account for its direct effect on income and wealth redistribution to achieve social welfare goals.
Li-e Wang, Yan Bai, Quan Jiang, Victor C. M. Leung · 6 authors
By facilitating multiple independent owners to jointly control a distributed network, blockchain can be used to solve the problem of device collaboration in complex networks (e.g., 5G, health care industries) through a distributed consensus mechanism. However, the state-of-the-art blockchain-based solutions cannot meet the demand of high transaction rate for those applications, due to the unavoidable data synchronization cost in decentralized systems. To address this issue, recent research splits blockchain nodes into multiple groups as parallel shardings to improve scalability at the cost of increased communication and storage per node. This paper proposes a fast and secure distributed blockchain protocol to reduce the traffic complexity while enhancing the transaction rates and the capability of fault-toleration. We introduce Proof-of-Behavior (PoB), a behavior-based incentive mechanism, for stimulating honest behavior and neutralizing malicious attacks. We design a blockchain protocol by integrating PoB with Raft, another classic consensus protocol with supervision, called Beh-Raft-Chain. Our approach replaces Practical Byzantine Fault Tolerance (PBFT) with Behavior-based Raft to lower the traffic complexity to O(n) and boost the capability of fault-toleration from n/4 to n/3, where n is the scale of blockchain. In our solution, we weigh all nodes based on their money and behaviors, and then set an adjustment parameter to increase the probability of candidate nodes being chosen beyond only a few nodes with the highest weight, in order to incentivize honest behavior in our mechanism. Our comparative experiments confirm Beh-Raft-Chain's theoretical low complexity and high fault-toleration properties.
Rafael Ziolkowski, Gianluca Miscione, Gerhard Schwabe
Blockchain comes with the promise of being a disruptive technology with the potential for novel ways of interaction in a wide range of applications. Following broader application, scholarly interest in the technology is growing, though an extensive analysis of blockchain applications from a governance perspective is lacking to date. This research pays special attention to the governance of blockchain systems and illustrates decision problems in 14 blockchain systems from four application domains. Based on academic literature, semi-structured interviews with representatives from those organizations, and content analysis of grey literature, common problems in blockchain governance have been singled out and contextualized. Studying their enactment revealed their relevance to major organizational theories in what we labelled “Patrolling the borders,” “External Legitimation,” “Reduction of Discretionality,” and “Temporal Management.” The identification of these problems enriches the scarce body of knowledge on the governance of blockchain systems, resulting in a better understanding of how blockchain governance links to existing concepts and how it is enacted in practice.