This paper describes a decentralized electronic voting system using blockchain technology with peer-to-peer network rather than the centralized voting system of server-client structure. In the proposed system, an Ethereum-based private blockchain network is configured and decentralized applications are implemented to store and distribute voting data to all nodes participating in the network to create secure and reliable electronic voting system. Smart contracts for electronic voting are implemented using the Solidity language and distributed to a configured network so that all users can view and vote on elections, and voting data are shared and contrasted by all users in the network, which makes it possible to build a safer and more reliable electronic voting system without third party involvement.
With the rapid development of Internet of Things (IoT), mobile crowdsensing (MCS), i.e., outsourcing sensing tasks to mobile devices or vehicles, has been proposed to address the problem of data collection in the scenarios such as smart city. Despite its benefits for a wide range of applications, MCS lacks an efficient incentive mechanism, restricting the development of IoT applications, especially for Internet of Vehicles (IoV)-a typical example of IoT applications; this is because vehicles are usually reluctant to participate these sensing tasks. Moreover, in practice, some sensing tasks may arrive suddenly (called an emergent task) in the IoV environment, but the resources of a single vehicle may be insufficient to handle, and thus multivehicles collaboration is required. In this case, the incentive mechanisms for the participation of multiple vehicles and the task scheduling for their collaborations are collectively needed. To address this important problem, we first propose a new model for the scenario of two vehicles collaboration, considering the situation of the emergent appearance of a task. In this model, for a general sensing task, we propose a bidding mechanism to better encourage vehicles to contribute their resources, and the tasks for those vehicles are scheduled accordingly. Second, for an emergent task, a novel time-window-based method is devised to manage the tasks among vehicles and to incent the vehicles to participate. Finally, we develop a blockchain framework to achieve the secured information exchange through smart contract for the proposed models in IoV.
With the increasing interest in connected vehicles along with electrification opportunities, there is an ongoing effort to automate the charging process of electric vehicles (EVs) through their capabilities to communicate with the infrastructure and each other. However, charging EVs takes time and thus in-advance scheduling is needed. As this process is done frequently due to limited mileage of EVs, it may expose the locations and charging pattern of the EV to the service providers, raising privacy concerns for their users. Nevertheless, the EV still needs to be authenticated to charging providers, which means some information will need to be provided anyway. While there have been many studies to address the problem of privacy-preserving authentication for vehicular networks, such solutions will be void if charging payments are made through traditional means. In this thesis, we tackle this problem by utilizing distributed applications enabled by Blockchain and smart contracts. We adapt zero-knowledge proofs to Blockchain for enabling privacy-preserving authentication while removing the need for a central authority. We introduce two approaches, one using a token-based mechanism and another utilizing the Pederson Commitment scheme to realize anonymous authentication. We also describe a protocol for the whole process which includes scheduling and charging operations. The evaluation of the proposed approaches indicates that the overhead of this process is affordable to enable real-time charging operations for connected EVs.
Nikhil Ravi, Shammya Shananda Saha, Anna Scaglione, Nathan G. Johnson
In recent years, many Blockchain based frameworks for transacting commodities on a congestible network have been proposed. In particular, as the number of controllable grid connected assets increases, there is a need for a decentralized, coupled economic and control mechanism to dynamically balance the entire electric grid. Blockchain based Transactive Energy (TE) systems have gained significant momentum as an approach to sustain the reliability and security of the power grid in order to support the flexibility of electricity demand. What is lacking in these designs, however, is a mechanism that physically verifies all the energy transactions, to keep the various inherently selfish players honest. In this paper, we introduce a secure peer-to-peer network mechanism for the physical validation of economic transactions cleared over a distributed ledger. The framework is $\textit{secure}$ in the sense that selfish and malicious agents that are trying to inject false data into the network are prevented from adversely affecting the optimal functionality of the verification process by detecting and isolating them from the communication network. Preliminary simulations focusing on TE show the workings of this framework.
Douglas W. Arner, Ross P. Buckley, Dirk Andreas Zetzsche, Bo Zhao · 7 authors
Abstract Since the launch of Bitcoin in 2009, cryptocurrencies and their underlying blockchain technology have risen to global attention. It is now clear Bitcoin and a number of other cryptocurrencies were the focus of one of the largest speculative bubbles in history. This chapter explores blockchain, cryptocurrencies and Initial Coin Offerings (ICOs), as well as policy and regulatory responses in Asia. It demystifies key aspects of blockchain systems, while also disentangling concepts that are often (incorrectly) used interchangeably, such as distributed ledgers and blockchains. The chapter provides data on total capital raised through ICOs and analyzes the distribution of ICOs by country and region. Based on this framework, it conducts a comprehensive analysis of regulatory statements and disparate policy approaches in Asian countries toward digital assets, focusing on cryptocurrencies, blockchain, and ICOs.
Nakamoto consensus, the protocol underlying Bitcoin, has the potential to secure a new class of systems which agree on non-mathematical truths. As an example of this capability, we propose a design for a trustless, data availability oracle. This exposition reduces the problem of determining whether or not a registered datum is publicly available to the problem of constructing a network in which either almost all nodes can download a given datum, or almost none of them can.
Thomas Durieux, João F. Ferreira, Rui Abreu, Pedro E. D. Cruz
Over the last few years, there has been substantial research on automated analysis, testing, and debugging of Ethereum smart contracts. However, it is not trivial to compare and reproduce that research. To address this, we present an empirical evaluation of 9 state-of-the-art automated analysis tools using two new datasets: i) a dataset of 69 annotated vulnerable smart contracts that can be used to evaluate the precision of analysis tools; and ii) a dataset with all the smart contracts in the Ethereum Blockchain that have Solidity source code available on Etherscan (a total of 47,518 contracts). The datasets are part of SmartBugs, a new extendable execution framework that we created to facilitate the integration and comparison between multiple analysis tools and the analysis of Ethereum smart contracts. We used SmartBugs to execute the 9 automated analysis tools on the two datasets. In total, we ran 428,337 analyses that took approximately 564 days and 3 hours, being the largest experimental setup to date both in the number of tools and in execution time. We found that only 42% of the vulnerabilities from our annotated dataset are detected by all the tools, with the tool Mythril having the higher accuracy (27%). When considering the largest dataset, we observed that 97% of contracts are tagged as vulnerable, thus suggesting a considerable number of false positives. Indeed, only a small number of vulnerabilities (and of only two categories) were detected simultaneously by four or more tools.
It has been proved that budget decentralization is becoming an effective system of local finances and an instrument of state regulation of regional development. It encourages regions to become financially independent and entrepreneurial, seeking additional resources for the needs and capabilities of the regions. To date, the main development of a democratic state is to ensure the welfare of every individual. According to the experience of developed European countries, the achievement of this goal is possible only under the conditions of high-quality public administration, which strengthens democratic institutions, eliminates inequities of access to public goods, improves the quality of public services, and improves the standard of living of the population. A priority direction for the development of a democratic state is to ensure the welfare of each individual citizen. In the context of the reform of the public finance system, the tendency towards decentralization in public administration, which results in the transfer of a number of powers to the local level, is relevant. Implementation of budget reform measures in the context of decentralization will contribute to ensuring a stable income base of local budgets, as well as enhancing their financial capacity, transparency, and efficiency of use of budget funds, and effective resolution of issues of socio-economic development of territories. Thus, financial decentralization makes it possible to balance the mechanisms of public service delivery with the needs and preferences of local residents. Population income is a traditional subject of research by scientists, which is related to the direct impact of population income on the socio-economic and political situation in society. This determines the priority direction of the formation of a system of methods and mechanisms of regulation of income of the population of any country
This paper explores empirically the behavior of the Chicago Mercantile Exchange (CME) bitcoin futures contract. The analysis focuses on the time period between the launch of the CME bitcoin futures contract on December 18, 2017, and September 17, 2018. The behavior of the bitcoin spot market and CME futures market is compared and analyzed along several dimensions: price, volatility and liquidity. By comparing the Garman-Klass volatilities of bitcoin spot and futures prices with those of different assets, we find that both the bitcoin spot and futures markets exhibit relatively high volatility compared to other assets. When the ratio of trading volume over open interest is used to measure liquidity, the bitcoin futures market shows a mid-level liquidity. We also find while the exchange margin is set to meet the normal price volatility that can cover the daily price movements within one standard deviation, the brokerage margin for bitcoin futures is set at beyond two standard deviations. Some brokerage firms impose non-margin requirements such as high net account balance and open position limits in addition to regular margins. We conclude that the brokerage firms' relatively high margin and non-margin requirements impede trading activity such as short-sales and thus, liquidity and efficiency in the bitcoin futures market has been slow to develop.
Purpose - The purpose of the research is to assess the current state of cryptocurrency in Vietnam and to provide several solutions and recommendations to the Government, the State Bank of Vietnam (SBV) and other relevant agencies for monitoring, managing, and controlling cryptocurrency effectively and efficiently. Research design, data and methodology - The study is based on the assessment and analysis of cryptocurrency in the world and the real situation of cryptocurrency in Vietnam in order to provide solutions to the controllable development of operation of this currency. Results - The study indicates the current operations of cryptocurrency in Vietnam and provides several suggestions to effectively control this currency. Conclusion - According to the study on current cryptocurrency and the situation of cryptocurrency in Vietnam, the author has proposed a number of solutions to provide suggestions to manage and develop the operations of cryptocurrency in a most practical manner. The governments of many countries in the world, including the Government of Vietnam, need more time as well as appropriate technology improvements to take advantage of these new digital currencies; therefore, they still need to ensure safety in compliance with the control and regulatory capabilities of the central government and central banks.
Ethereum is a distributed blockchain that can execute smart contracts, which inter-communicate and perform transactions automatically. The execution of smart contracts is paid in the form of gas, which is a monetary unit used in the Ethereum blockchain. The Ethereum Virtual Machine (EVM) provides the metering capability for smart contract execution. Instruction costs vary depending on the instruction type and the approximate computational resources required to execute the instruction on the network. The cost of gas is adjusted using transaction fees to ensure adequate payment of the network. In this work, we highlight the "real" economics of smart contracts. We show that the actual costs of executing smart contracts are disproportionate to the computational costs and that this gap is continuously widening. We show that the gas cost-model of the underlying EVM instruction-set is wrongly modeled. Specifically, the computational cost for the SLOAD instruction increases with the length of the blockchain. Our proposed performance model estimates gas usage and execution time of a smart contract at a given block-height. The new gas-cost model incorporates the block-height to eliminate irregularities in the Ethereum gas calculations. Our findings are based on extensive experiments over the entire history of the EVM blockchain.
Georgia Avarikioti, Antoine Desjardins, Eleftherios Kokoris-Kogias, Roger Wattenhofer
Sharding distributed ledgers is a promising on-chain solution for scaling blockchains but lacks formal grounds, nurturing skepticism on whether such complex systems can scale blockchains securely. We fill this gap by introducing the first formal framework as well as a roadmap to robust sharding. In particular, we first define the properties sharded distributed ledgers should fulfill. We build upon and extend the Bitcoin backbone protocol by defining consistency and scalability. Consistency encompasses the need for atomic execution of cross-shard transactions to preserve safety, whereas scalability encapsulates the speedup a sharded system can gain in comparison to a non-sharded system. Using our model, we explore the limitations of sharding. We show that a sharded ledger with $n$ participants cannot scale under a fully adaptive adversary, but it can scale up to $m$ shards where $n=c'm\log m$, under an epoch-adaptive adversary; the constant $c'$ encompasses the trade-off between security and scalability. This is possible only if the sharded ledgers create succinct proofs of the valid state updates at every epoch. We leverage our results to identify the sufficient components for robust sharding, which we incorporate in a protocol abstraction termed Divide & Scale. To demonstrate the power of our framework, we analyze the most prominent sharded blockchains (Elastico, Monoxide, OmniLedger, RapidChain) and pinpoint where they fail to meet the desired properties.
Georgia Avarikioti, Eleftherios Kokoris-Kogias, Roger Wattenhofer
Sharding distributed ledgers is the most promising on-chain solution for scaling blockchain technology. In this work, we define and analyze the properties a sharded distributed ledger should fulfill. More specifically, we show that a sharded blockchain cannot be scalable under a fully adaptive adversary, but it can scale up to $O(n/\log n)$ under an epoch-adaptive adversary. This is possible only if the distributed ledger creates succinct proofs of the valid state updates at the end of each epoch. Our model builds upon and extends the Bitcoin backbone protocol by defining consistency and scalability. Consistency encompasses the need for atomic execution of cross-shard transactions to preserve safety, whereas scalability encapsulates the speedup a sharded system can gain in comparison to a non-sharded system. We introduce a protocol abstraction and highlight the sufficient components for secure and efficient sharding in our model. In order to show the power of our framework, we analyze the most prominent shared blockchains (Elastico, Monoxide, OmniLedger, RapidChain) and pinpoint where they fail to meet the desired properties.
Yackolley Amoussou-Guenou, Antonella Del Pozzo, Maria Potop-Butucaru, Sara Tucci-Piergiovanni
Committee-based blockchains are among the most popular alternatives of proof-of-work based blockchains, such as Bitcoin. They provide strong consistency (no fork) under classical assumptions, and avoid using energy-consuming mechanisms to add new blocks in the blockchain. For each block, these blockchains use a committee that executes Byzantine-fault tolerant distributed consensus to decide the next block they will add in the blockchain. Unlike Bitcoin, where there is only one creator per block with high probability, in committee-based blockchain any block is cooperatively created. In order to incentivize committee members to participate to the creation of new blocks rewarding schemes have to be designed. In this paper, we study the fairness of rewarding in committee-based blockchains and we provide necessary and sufficient conditions on the system communication under which it is possible to have a fair reward mechanism.
Ivan Homoliak, Sarad Venugopalan, Daniel Reijsbergen, Qingze Hum · 6 authors
Blockchains are distributed systems, in which security is a critical factor for their success. However, despite their increasing popularity and adoption, there is a lack of standardized models that study blockchain-related security threats. To fill this gap, the main focus of our work is to systematize and extend the knowledge about the security and privacy aspects of blockchains and contribute to the standardization of this domain. We propose the security reference architecture (SRA) for blockchains, which adopts a stacked model (similar to the ISO/OSI) describing the nature and hierarchy of various security and privacy aspects. The SRA contains four layers: (1) the network layer, (2) the consensus layer, (3) the replicated state machine layer, and (4) the application layer. At each of these layers, we identify known security threats, their origin, and countermeasures, while we also analyze several cross-layer dependencies. Next, to enable better reasoning about security aspects of blockchains by the practitioners, we propose a blockchain-specific version of the threat-risk assessment standard ISO/IEC 15408 by embedding the stacked model into this standard. Finally, we provide designers of blockchain platforms and applications with a design methodology following the model of SRA and its hierarchy.
Blockchain is a popular method to ensure security for trusted systems. The benefits include an auditable method to provide decentralized security without a trusted third party, but the drawback is the large computational resources needed to process and store the ever-expanding chain of security blocks. The promise of blockchain for edge devices (e.g., internet of things) poses a variety of challenges and strategies before adoption. In this paper, we explore blockchain methods and examples, with experimental data to determine the merits of the capabilities. As for an aerospace example, we address a notional example for Automatic dependent surveillance-broadcast (ADS-B) from Flight24 data (https://www.flightradar24.com/) to determine whether blockchain is feasible for avionics systems. The methods are incorporated into the Lightweight Internet of Things (IoT) based Smart Public Safety (LISPS) framework. By decoupling a complex system into independent sub-tasks, the LISPS system possesses high flexibility in the design process and online maintenance. The Blockchain-enabled decentralized avionics services provide a secured data sharing and access control mechanism. The experimental results demonstrate the feasibility of the approach.
Recently, blockchain technology has been used in various sectors of the economy. Mainly, it is actively implemented in the financial sector of the state. But, now more and more we are talking about its use in the agro-industrial complex. Agriculture provides over 14% of Ukraine’s GDP, making it one of the most important industries in the world. The agricultural sector brings every third dollar that Ukraine receives. Since a huge number of jobs depend on the sustainable success of Ukraine’s agro-industrial complex, big stakes are placed on ensuring that agriculture remains a viable and competitive market for all. Negotiating changes in international trade policy and supporting affordable labor on the extent of potential border strengthening present two new challenges for agriculture in the future. However, older, more persistent threats to the agribusiness sector are also present, as they involve decisions about what technology should be used and when it is appropriate to invest in innovation.
In recent years, the term “blockchain” has been sprinkled widely and the hype around it attracts billions in investments. The promises that this technology can be a solution to many of society’s present problems have drawn attention from all sectors, including development aid. The historical recognition of potential and actual corruption resulting from development aid sparked a rise in demands for more transparency and accountability in this sector. So far, there have been reflections in different academic disciplines about the potentials of Blockchain in this area. However, little empirical investigation has been conducted to understand the technological and institutional enablers and barriers for its adoption in the development aid sector. This study aims to take initial steps towards such understanding with a focus on the potential role for Blockchain Technology in financial aid flows through an analysis of the donors’ perspectives. Our research is based on diverse qualitative material. It relies on reports and discussion papers produced by donor organizations and on case studies of two start-ups focused on introducing Blockchain into development aid management. Besides a body of archival qualitative material, we conducted interviews with different actors in the development financing field. Based on an inductive qualitative methodology, we grouped findings into three categories of barriers and enablers: discursive, technological and institutional. Our study shows that discourses about Blockchain Technology vary a lot and there is a lack of common framing of its definition, attributes, and insufficient engagement around these concerns between different actors. Overall, the ability to increase the visibility of cash flows and a potential to reduce administration costs were perceived to be the most useful features, combined with the desire/need expressed by some donors to be at the forefront of technological developments. Lack of understanding about this technology and fear of its complexity and related security challenges were the most cited technological obstacles. Lack of institutional structures for rule making and for enabling field-level exchanges and knowledge production around Blockchain-based projects is currently the most prominent challenge to its diffusion and wider adoption.
The number of IoT devices is growing at an exponential rate.It is expected that by 2020, there will be approximately 30 billion internet-connected devices and 500 billion by 2030.Not only, does it increase security concerns but will give rise to interoperability issues.In this paper, the recently introduced Ethereum network will be utilised with respect to Internet of Things to create an infrastructure compatible with IoT devices.With an addition of an automated, immutable smart contract that will aid the interoperability of various devices through the heterogenousfriendly Ethereum network.The true potential of Ethereum, when combined with IoT, will be explored and demonstrated.Demonstrated through an implementation in which power will be provided to a room embedded with various IoT devices upon payment (in the form of rent) into a landlord's smart contract [1].
With the increasing complexity of payments and the distances between participants in financial transactions, the number of third parties involved in making payments is also growing. This entails an increase in commissions. Cryptocurrency solves this problem. This, in its way, is a digital “cash” that can be used by network participants, regardless of the distance and type of transaction. Cryptocurrency is a new type of electronic money, is rapidly gaining popularity.Purpose. The purpose of the article is to study the directions of increasing the level of development of cryptocurrencies in Ukraine.
Bitcoin is a cryptocurrency (digitized money) and is a worldwide decentralized payment system that is allowed and kept alive due to the technology called Block Chain. TheTnetworkTconsistsTofTpeer-to-peer transactions and these transactions are verified by using cryptography technology bank. Chain technology keeps the records of public distributed ledger. Bitcoins can be earned as a reward through mining. This currency can is convertible into other currencies, products and services. Bitcoin has been emerging as famous digital currency and getting popularity all over for quick transition. Moreover, bitcoin will be a financial asset because it has profitable results. The purpose of this research study is to explain complete working of bitcoins technology, highlights applications and research challenges to be address and current future international market scope of Bitcoin technology.
Mohammad Abdul Matin Chowdhury, Dzuljastri Bin Abdul Razak
Technology advanced has brought rapid changes in all human activities along with financial activities and tools. Digital currency one of the technological innovations which have taken significant focuses from consumers, investors, researchers, entrepreneurs and policy makers around the world. with the trend of changing patterns, Islamic finance is rapidly developing all over the world by serving Muslims and non-Muslims, as a result, it is mandatory for Islamic finance to adapt with modern technology systems in terms of providing innovative products and services to the consumers in line with shariah perspectives. As a result, cryptocurrency (digital currency) has taken the focus on Islamic scholars in regards of its permissibility. There are many arguments over the permissibility issues. Therefore, this study aims to explore those issues and mechanisms of cryptocurrency in order to evaluate with Islamic perspective. This study gathered secondary sources from past literatures, books, news and websites with qualitative approach. The findings inclined that there are still lacking in mechanisms of digital currency to comply with Islamic perspective such as real asset backed and legal authorization. The findings of this study will benefit the Islamic scholars and policy makers along with Muslim consumers and investors in regards of permissibility and developing existing cryptocurrency to widely use in the Islamic finance and banking sector.
Maurantonio Caprolu, Simone Raponi, Gabriele Oligeri, Roberto Di Pietro
Cryptojacking occurs when an adversary illicitly runs crypto-mining software over the devices of unaware users. This novel cybersecurity attack, that is emerging in both the literature and in the wild, has proved to be very effective given the simplicity of running a crypto-client into a target device. Several countermeasures have recently been proposed, with different features and performance, but all characterized by a host-based architecture. The cited solutions, designed to protect the individual user, are not suitable for efficiently protecting a corporate network, especially against insiders. In this paper, we propose a network-based approach to detect and identify crypto-clients activities by solely relying on the network traffic, even when encrypted and mixed with non-malicious traces. First, we provide a detailed analysis of the real network traces generated by three major cryptocurrencies, Bitcoin, Monero, and Bytecoin, considering both the normal traffic and the one shaped by a VPN. Then, we propose Crypto-Aegis, a Machine Learning (ML) based framework built over the results of our investigation, aimed at detecting cryptocurrencies related activities, e.g., pool mining, solo mining, and active full nodes. Our solution achieves a striking 0.96 of F1-score and 0.99 of AUC for the ROC, while enjoying a few other properties, such as device and infrastructure independence. Given the extent and novelty of the addressed threat we believe that our approach, supported by its excellent results, pave the way for further research in this area.
Andreas Vlachos, Klitos Christodoulou, Elias Iosif
This paper presents the design of a Blockchain Readiness Index (BRI) to be used as a tool for assisting nations to monitor the level of Blockchain maturity according to their suitability on hosting blockchain-based activities, and successfully adopting a blockchain regulatory framework. BRI is a composite index that combines a variety of indicators from a range of sources to a single score. The proposed methodology attempts to fill a knowledge gap by evaluating the relatively unexplored area of blockchain adoption per nation. The index presented in this paper aims to distinguish between the most promising and non-hostile countries, acting as the basis for professional work, decision making and operations of organizations, investors, academics, and other stakeholders within the blockchain space. As the index is updated regularly, all new developments on the fast-changing landscape of blockchain and cryptocurrencies are reflected. In addition, this research aims to go beyond the regulatory environment towards examining several other factors such as local engagement, expertise, investments, and the need for a decentralized provision of services. This paper presents an overview of the landscape of similar attempts on designing such indexes by reviewing and identifying potential gaps and opportunities for improving their methodological design that can lead to more accurate and relevant conclusions. In addition, with this paper we contribute a systematic methodology for building a BRI using techniques from the information retrieval domain to normalize the non-normalized values, and a cosine similarity measure to derive an index ranking consisting of various nations. More specifically the proposed BRI covers a wide range of blockchain readiness indicators which can be organized into the following “pillars”: (1) Government Regulation, (2) Research, (3) Technology, (4) Industry, and (5) User Engagement. An empirical evaluation reports preliminary but promising results of the algorithmic design methodology showing evidence that, the identified indicators are sufficient for developing our index when compared to judgements made by human experts.