Jason Teutsch, Vitalik Buterin, Christopher L. Brown
Ethereum has emerged as a dynamic platform for exchanging cryptocurrency tokens. While token crowdsales cannot simultaneously guarantee buyers both certainty of valuation and certainty of participation, we show that if each token buyer specifies a desired purchase quantity at each valuation then everyone can successfully participate. Our implementation introduces smart contract techniques which recruit outside participants in order to circumvent computational complexity barriers.
In December 2015, a bounty emerged to establish both reliable communication and secure transfer of value between the Dogecoin and Ethereum blockchains. This prized "Dogethereum bridge" would allow parties to "lock" a DOGE coin on Dogecoin and in exchange receive a newly minted WOW token in Ethereum. Any subsequent owner of the WOW token could burn it and, in exchange, earn the right to "unlock" a DOGE on Dogecoin. We describe an efficient, trustless, and retrofitting Dogethereum construction which requires no fork but rather employs economic collateral to achieve a "lock" operation in Dogecoin. The protocol relies on bulletproofs, Truebit, and parametrized tokens to efficiently and trustlessly relay events from the "true" Dogecoin blockchain into Ethereum. The present construction not only enables cross-platform exchange but also allows Ethereum smart contracts to trustlessly access Dogecoin. A similar technique adds Ethereum-based smart contracts to Bitcoin and Bitcoin data to Ethereum smart contracts.
Blockchain is the core technology of many cryptocurrencies. Blockchain as a distributed ledger technology has received extensive research attention. In addition to cryptography and P2P (peer-to-peer) technology, consensus protocols are also a fundamental part of the blockchain technology. A good consensus protocol can guarantee the fault tolerance and security of the blockchain systems. The consensus protocols currently used in most blockchain systems can be broadly divided into two categories: the probabilistic-finality consensus protocols and the absolute-finality consensus protocols. This paper introduces some of the main consensus protocols of these two categories, and analyzes their strengths and weaknesses as well as the applicable blockchain types.
This Article argues that, contrary to the common belief that Bitcoin enables tax evasion, the Internal Revenue Service (âIRSâ) can increasingly police transactions in Bitcoin. First, commercial and technical intermediaries have emerged as part of Bitcoinâs ecosystem. This diverse set of intermediaries can facilitate tax enforcement, as the litigation over the IRSâs summons on Coinbaseâthe largest domestic digital asset exchangeâand subsequent IRS efforts show. These intermediaries could report transactions to the IRS or even, one day, withhold and remit tax payments. Second, the publicly visible, trustworthy nature of Bitcoinâs blockchainâits unique role as a shared truthâallows tax authorities to observe transaction flows. This renders Bitcoin unusually regulable for tax purposes, as recent efforts by the IRS to rely on Bitcoinâs blockchain to police tax evasion demonstrate. The Article offers a proposal by which the IRS might make better use of Bitcoinâs blockchain: the IRS can tailor an existing program to reward technically savvy whistleblowers who scour Bitcoinâs blockchain and determine identities that correspond to public Bitcoin addresses at issue.
Mehrdokht Pournader, Yangyan Shi, Stefan Seuring, S.C. Lenny Koh
This paper presents current academic and industrial frontiers on blockchain application in supply chain, logistics and transport management. We conduct a systematic review of the literature and find four main clusters in the co-citation analysis, namely Technology, Trust, Trade, and Traceability/Transparency. For each cluster, and based on the pool of articles included in it, we apply an inductive method of reasoning and discuss the emerging themes and applications of blockchains for supply chains, logistics and transport. We conclude by discussing the main themes for future research on blockchain technology and its application in industry and services.
The application of blockchain technology to the energy sector promises to derive new operating models focused on local generation and sustainable practices, which are driven by peer-to-peer collaboration and community engagement. However, real-world energy blockchains differ from typical blockchain networks insofar as they must interoperate with grid infrastructure, adhere to energy regulations, and embody engineering principles. Naturally, these additional dimensions make real-world energy blockchains highly dependent on the participation of grid operators, engineers, and energy providers. Although much theoretical and proof-of-concept research has been published on energy blockchains, this research aims to establish a lens on real-world projects and implementations that may inform the alignment of academic and industry research agendas. This research classifies 131 real-world energy blockchain initiatives to develop an understanding of how blockchains are being applied to the energy domain, what type of failure rates can be observed from recently reported initiatives, and what level of technical and theoretical details are reported for real-world deployments. The results presented from the systematic analysis highlight that real-world energy blockchains are (a) growing exponentially year-on-year, (b) producing relatively low failure/drop-off rates (~7% since 2015), and (c) demonstrating information sharing protocols that produce content with insufficient technical and theoretical depth.
The Cloud Computing Paradigm simplified the IT infrastructure management thereby making the organiza-tions and enterprises to rapidly migrate from conventional model to service driven model. The service driven model allows the users to access, maintain and backup the files from remote location over the internet through the central-ized cloud service providers. Inspite of major advantages, there are some concerns for the safety and privacy risks of organizational and users sensitive information in cloud stor-age. The existing service oriented model uses distributed key management which encrypts the data and stores it in cloud servers to provide the authentication to data, but it addresses challenges in identifying ownership of data, boot-strapping problem and securing the keys. The proposed system uses block chain, a distributed ledger for user authentication in cloud server and Hash graph with asynchronous byzantine fault tolerance algorithm is proposed for replicat-ed state machines with guaranteed Byzantine fault-tolerance and it can be utilized in the IT Infrastructure envi-ronment which solves the hassles of maintaining security keys
Smart contract is a special program that manages digital assets on blockchain. It is difficult to recover the loss if users make transactions through buggy smart contracts, which cannot be directly fixed. Hence, it is important to ensure the correctness of smart contracts before deploying them. This paper proposes a systematic framework to mutation testing for smart contracts on Ethereum, which is currently the most popular open blockchain for deploying and running smart contracts. Fifteen novel mutation operators have been designed for Ethereum Smart Contracts (ESC), in terms of keyword, global variable/function, variable unit, and error handling. An empirical study on 26 smart contracts in four Ethereum DApps has been conducted to evaluate the effectiveness of mutation testing. The experimental results show that our approach can outperform the coverage-based approach on defect detection rate (96.01% vs. 55.68%). The ESC mutation operators are effective to reveal real defects and we found 117 out of 729 real bug reports are related to our operators. These show the great potential of using mutation testing for quality assurance of ESC.
A generalized distributed tool for mobility choice modelling is presented, where participants do not share personal raw data, while all computations are done locally. Participants use Blockchain based Smart Mobility Data-market (BSMD), where all transactions are secure and private. Nodes in blockchain can transact information with other participants as long as both parties agree to the transaction rules issued by the owner of the data. A case study is presented where a mode choice model is distributed and estimated over BSMD. As an example, the parameter estimation problem is solved on a distributed version of simulated annealing. It is demonstrated that the estimated model parameters are consistent and reproducible.
Botnets are becoming increasingly prevalent as the primary enabling technology in a variety of malicious campaigns such as email spam, click fraud, distributed denial-of-service (DDoS) attacks, and cryptocurrency mining. Botnet technology has continued to evolve rapidly making detection a very challenging problem. There is a fundamental need for robust detection methods that are insensitive to characteristics of a specific botnet and are generalizable across different botnet types. We propose a novel supervised approach to detect malicious botnet hosts by tracking a host's network activity over time using a Long Short-Term Memory (LSTM) based neural network architecture. We build a prototype to demonstrate the feasibility of our approach, evaluate it on the CTU-13 dataset, and compare our performance against existing detection methods. We show that our approach results in a more generalizable, botnet-agnostic detection methodology, is amenable to real-time implementation, and performs well compared to existing approaches, with an overall accuracy score of 96.2%.
The unique combination of social and economic factors has brought about a dynamic and rapidly-evolving blockchain ecosystem in Asia. This paper systematically reviewed the development of four fast-growing blockchain hubs in Asia, namely China, Japan, Singapore and South Korea using secondary data sources. These countries are fast-growing based on the development of its digital, technological and regulatory infrastructure, patent applications, cryptocurrency trading volume and Initial Crypto-token Offerings (ICOs) activities. The review included insights into the different regulatory approaches, the blockchain startup scenes, selected enterprise or government-backed projects, as well as the research and educational landscape. Our findings suggested that the regulators, industry players, and academic institutions were purposeful and deliberate in nurturing blockchain technology innovation. Future development would be dependent on the regulatory, technological, as well as talent capability support unique to each blockchain hub.
Introduction. In the period of crisis aggravation in the economy of Ukraine, a household and economic entity, as a rule, avoid saving financial resources. They prefer to invest their capital in foreign currency, valuable things, real estate and gold. The choice of the investment object is often determined by the level of fluctuations of its value depending on the political situation in the state, extent of intervention of the third parties in the process of ownership and disposal of the object, legal security and so on. Lately more and more individuals note the desired criteria in relatively new instrument of the financial market - cryptocurrency.Purpose. The purpose of the article is the determination of modern features of cryptocurrency functioning in the world and assessment of the advantages and disadvantages of their use.Results. The essence of the cryptocurrency determines its main advantages: the confidentiality and data security of owners; independence from the state; the lack of territorial and time restrictions in transactions; the low cost of service, etc. As a result, the cryptocurrency is gaining the increasing popularity among the population, the infrastructure of its sale via terminals is forming (there were already about 5000 ones in 2018), futures contracts for Bitcoins are being put into practice, the network of commercial and production structures is expanding. It gives wide opportunities for cryptocurrency payment.Conclusion. The cryptocurrency becomes more and more important part of society and work technology all over the world. The number of people who use cryptocurrency increased and is approaching the population of a small country â from 2.9 to 5.8 million people. The majority are inhabitants of North America and Europe. For the effective functioning of cryptocurrencies their institutionalization is necessary. It can be done in two ways: first, it is a legal institutionalization, and secondly it is the market institutionalization, which is carried out through the establishment of formal and informal rules for cryptocurrency functioning.
While Ethereum run in public networks which make the blockchain size large and transaction run time longer than time for private or national network, that led to continuous worries over the expanding size of Ethereum Blockchain, which certainly reduce Cryptocurrency's effectiveness. The estimations were on increase and believed it would cross the node limit of 1 TB terribly shortly. If new consumer a full node enters to that blockchain and cryptocurrency world, a node is a computer software cum database of the blockchain, which a full node client must download on their personal computers to become a full node in the blockchain. in this way, the client can be verifying transaction on the network with the help of other nodes on the system. We proposed to implement national cryptocurrency which developed using Ethereum as a development platform that could serve national or regional people that has limited or slow internet connections like Iraq, in addition payments in countries with unstable fiat currencies, although cryptocurrencies are suffering from unstable exchange rates against fiat currencies, the use of national cryptocurrency instead of the native fiat cash could even be a far better alternative for individuals in certain countries like Iraq, Iran and Syria, with high rate of inflation. The reminder of this paper is arranging as following: an introduction, the advantages and drawbacks of cryptocurrencies, Background on Blockchain and Ethereum, implementation, results and conclusion.
The article has been devoted to the system analysis of supply chains digital integration. The main goal is to study the practical significance of the blockchain in terms of digital integration of supply chains, to identify areas for further development. World experience of implementing blockchain projects in supply chains has been analyzed, trends in the use of digitalization technologies in logistics have been identified, components of digital supply chain integration have been considered. The general scheme of work with information is the collection of relevant data from news messages, evaluation of requests on the Internet by statistics analysis tools âYandex. Choice of wordsâ and âGoogle Trendsâ, analysis of legal and law enforcement documents using the search and analytics capabilities reference-legal systems, study of intellectual property through the service âYandex. PatentsÂť. Systematization of the data was carried out by expert methods by the specialists of the Logistics Department from the State University of Management. The phenomenon of the popularity of the term âblockchainâ has been examined, a plenty of papers, news articles, legal acts, devoted to the blockchain (distributed registry) and related with it technologies has been studied. The shortcomings of the blockchain, complicating the practical commercial application of technology in logistics and the economy as a whole, has been systematized; domestic legal support, regulating the issues of blockchain, cryptocurrency and related concepts has been analyzed; innovations (technologies, inventions, platforms and systems), related to the digitalization of the economy have been classified, and the components of digital integration of supply chains and logistics business processes have been formulated. The results of this study can be used to consolidate information about the opportunities and problems of blockchain in connection with related technologies, as well as in making decisions about the application of blockchain in logistics in order to integrate modern supply chains.
Classification-as-a-Service (CaaS) is widely deployed today in machine intelligence stacks for a vastly diverse set of applications including anything from medical prognosis to computer vision tasks to natural language processing to identity fraud detection. The computing power required for training complex models on large datasets to perform inference to solve these problems can be very resource-intensive. A CaaS provider may cheat a customer by fraudulently bypassing expensive training procedures in favor of weaker, less computationally-intensive algorithms which yield results of reduced quality. Given a classification service supplier $S$, intermediary CaaS provider $P$ claiming to use $S$ as a classification backend, and customer $C$, our work addresses the following questions: (i) how can $P$'s claim to be using $S$ be verified by $C$? (ii) how might $S$ make performance guarantees that may be verified by $C$? and (iii) how might one design a decentralized system that incentivizes service proofing and accountability? To this end, we propose a variety of methods for $C$ to evaluate the service claims made by $P$ using probabilistic performance metrics, instance seeding, and steganography. We also propose a method of measuring the robustness of a model using a blackbox adversarial procedure, which may then be used as a benchmark or comparison to a claim made by $S$. Finally, we propose the design of a smart contract-based decentralized system that incentivizes service accountability to serve as a trusted Quality of Service (QoS) auditor.
We outline a token model for Truebit, a retrofitting, blockchain enhancement which enables secure, community-based computation. The model addresses the challenge of stable task pricing, as raised in the Truebit whitepaper, without appealing to external oracles, exchanges, or hierarchical nodes. The system's sustainable economics and fair market pricing derive from a mintable token format which leverages existing tokens for liquidity. Finally, we introduce a governance layer whose lifecycles culminates with permanent dissolution into utility tokens, thereby tending the network towards autonomous decentralization.
The article proposes to carry out the process of developing a new financial system of the BRICS States in the following sequence: to transfer foreign trade between the States to settlements in national currencies, with the subsequent development of its own unit of account, which will subsequently be able to replace the dollar and the Euro in mutual settlements within the BRICS; develop your own cryptocurrency or choose one of the existing cryptocurrencies, which for a certain period will be one of the possible elements of the settlement mechanism in the mutual trade of these five countries; to develop supra-national crypto-currency for the countries members of the BRICS. This process will be very complex, as it will require many technological, macroeconomic and organizational challenges.To solve the problem of building a new financial and monetary system of the BRICS countries, the article analyzes the actual level of digitalization of financial activities in the countries of the Association, on the basis of which proposals are developed and the following conclusions are formulated: crypto-currency operations are not completely prohibited in any of the States of the Association, and the prohibitions apply only to certain operations (ISO, mining, exchanges). Cryptocurrency is not recognized as a legal means of payment; in the BRICS countries there are no own, national cryptocurrencies, and only projects of future cryptocurrencies are developed, taking into account the features of the set goalsof economic development and management of cryptocurrency activities; the countries of the Association do not abandon the use of blockchain technology in the field of economy and Finance, as it ensures the openness and security of data storage, the creation of centralized exchanges, the exchange of goods and services; the BRICS countries should be interested in a gradual shift away from dollar dependence. The instruments of this movement are the national currency, its own, internal unit of account, its own national cryptocurrency, supranational cryptocurrency.
Steve Hyun, Jimin Lee, JongâMin Kim, Chulhee Jun
Exploring dependence structures between financial time series has been important within a wide range of applications. The main aim of this paper is to examine dependence relationships among five well-known cryptocurrenciesâBitcoin, Ethereum, Litecoin, Ripple, and Stellaâby a copula directional dependence (CDD). By employing a neural network autoregression model to avoid the serial dependence in each individual cryptocurrency, we generate residuals of the fitted models with time series of daily log-returns in percentage of the five cryptocurrencies and then we apply a Gaussian copula marginal beta regression model to the residuals to explore the CDD. The results show that the CDD from Bitcoin to Litecoin is highest among all ordered directional dependencies and the CDDs from Ethereum to the other four cryptocurrencies are relatively higher than the CDDs to Ethereum from those cryptocurrencies. This finding implies that the return shocks of Bitcoin have the most effect on Litecoin and the return shocks of Ethereum relatively influence the shocks on the other four cryptocurrencies instead of being affected by them. This allows investors to build the market-timing strategies by observing the directional flow of return shocks among cryptocurrencies.
Lukman Adewale Ajao, James Agajo, Emmanuel Adewale Adedokun, Loveth Karngong
This research work proposes a method for the securing and monitoring of petroleum product distribution records in a decentralized ledger database using blockchain technology. The aim of using this technique is to secure the transaction of distributed ledgers in a database and to protect records from tampering, fraudulent activity, and corruption by the chain participants. The blockchain technology approach offers an efficient security measure and novel advantages, such as in the transaction existence and distribution ledger management between the depot, transporter, and retailing filling station. Others advantages are transparency, immunity to fraud, insusceptibility to tampering, and maintaining record order. The technique adopted for this secure distributed ledger database is crypto hash algorithm-1 (SHA-1)-based public permissioned blockchain and telematics, while this telematics approach is an embedded system integrated into an in-vehicle model for remote tracking of geolocation (using Global Positioning System (GPS)), monitoring, and far-off data acquisition in a real-time. The scope of the data in the secure distributed ledger database (using blockchain) developed are identification (ID) of the tanker operator, Depot name, Source station ID, Destination station ID, Petroleum product volume, Transporter ID, and Geographic automobiles location. This system proved to be efficient, secure, and easy to maintain as it does not permit any individual for records tampering, but supports agreement of ~75% of participants in the chain to make changes.
A blockchain is a system for storing and sharing information that is secure because of its transparency. Each block in the chain is both its own independent unit containing its own information, and a dependent link in the collective chain, and this duality creates a network regulated by participants who store and share the information, rather than a third party. Blockchain has many applications in healthcare, and can improve mobile health applications, monitoring devices, sharing and storing of electronic medical records, clinical trial data, and insurance information storage. Research about blockchain and healthcare is currently limited, but blockchain is on the brink of transforming the healthcare system; through its decentralized principles, blockchain can improve accessibility and security of patient information, and can therefore overturn the healthcare hierarchy and build a new system in which patients manage their own care.
Open access
Blockchain Technology Applications and Security
Neuroethics, Human Enhancement, Biomedical Innovations
Consensus is one of the most fundamental distributed computing problems. In particular, it serves as a building block in many replication based fault-tolerant systems and in particular in multiple recent blockchain solutions. Depending on its exact variant and other environmental assumptions, solving consensus requires multiple communication rounds. Yet, there are known optimistic protocols that guarantee termination in a single communication round under favorable conditions. In this paper we present a generic optimizer than can turn any consensus protocol into an optimized protocol that terminates in a single communication round whenever all nodes start with the same predetermined value and no Byzantine failures occur (although node crashes are allowed). This is regardless of the network timing assumptions and additional oracle capabilities assumed by the base consensus protocol being optimized. In the case of benign failures, our optimizer works whenever the number of faulty nodes $f<n/2$. For Byzantine behavior, our optimizer's resiliency depends on the validity variant sought. In the case of classical validity, it can accommodate $f<n/4$ Byzantine failures. With the more recent external validity function assumption, it works whenever $f<n/3$. Either way, our optimizer only relies on oral messages, thereby imposing very light-weight crypto requirements.
This study investigates the role and functionality of special nucleotide sequences (DNA signatures) to detect the presence of an organism and to distinguish it from all others. After highlighting vulnerabilities of the prevalent DNA signature paradigm for the identification of agricultural genetically modified (GM) organisms it will be argued that these so-called signatures really are no signatures at all - when compared to the notion of traditional (handwritten) signatures and their generalizations in the modern (digital) world. It is suggested that a recent contamination event of an unauthorized GM Bacillus subtilis strain (Paracchini et al. (2017)) in Europe could have been - or the same way could be - the consequence of exploiting gaps of prevailing DNA signatures. Moreover, a recent study (Mueller (2019)) proposes that such DNA signatures may intentionally be exploited to support the counterfeiting or even weaponization of GM organisms (GMOs). These concerns mandate a re-conceptualization of how DNA signatures need to be realized. After identifying central issues of the new vulnerabilities and overlying them with practical challenges that bio-cyber hackers would be facing, recommendations are made how DNA signatures may be enhanced. To overcome the core problem of signature transferability in bioengineered mediums, it is necessary that the identifier needs to remain secret during the entire verification process. On the other hand, however, the goal of DNA signatures is to enable public verifiability, leading to a paradoxical dilemma. It is shown that this can be addressed with ideas that underlie special cryptographic signatures, in particular those of âzero-knowledgeâ and âinvisibility.â This means more than mere signature hiding, but relies on a knowledge-based proof and differentiation of a secret (here, as assigned to specific clones) which can be realized without explicit demonstration of that secret. A reconceptualization of these principles can be used in form of a combined (digital and physical) method to establish confidentiality and prevent un-impersonation of the manufacturer. As a result, this helps mitigate the circulation of possibly hazardous GMO counterfeits and also addresses the situation whereby attackers try to blame producers for deliberately implanting illicit adulterations hidden within authorized GMOs.
Bitcoin jest jednÄ z waĹźnych innowacji finansowych ostatnich lat, bÄdÄ cÄ wynikiem rozwoju technologicznego i informatyzacji rynku finansowego. Mimo stosunkowo krĂłtkiej historii tej kryptowaluty, wyksztaĹciĹo siÄ wiele gieĹd wyspecjalizowanych w jej obrocie, a na rynku finansowym pojawiĹy siÄ pierwsze prĂłby utworzenia opartych na niej instrumentĂłw â pasywnie i aktywnie zarzÄ dzanych exchange-traded funds. W artykule przedstawiono te fundusze oraz, ze wzglÄdu na brak dywersyfikacji ich portfeli, podjÄto prĂłbÄ okreĹlenia, czy inwestycja za ich pomocÄ jest lepsza od bezpoĹredniego lokowania ĹrodkĂłw na rynku bitcoina. Ponadto zidentyfikowano podstawowe czynniki ryzyka, zwiÄ zane z inwestowaniem w analizowane fundusze oraz dokonano ich klasyfikacji.
Matthew Johnson, Michael N. Jones, Mark Shervey, Joel T. Dudley ¡ 5 authors
Decentralized apps (DApps) are computer programs that run on a distributed computing system, such as a blockchain network. Unlike the client-server architecture that powers most internet apps, DApps that are integrated with a blockchain network can execute app logic that is guaranteed to be transparent, verifiable, and immutable. This new paradigm has a number of unique properties that are attractive to the biomedical and health care communities. However, instructional resources are scarcely available for biomedical software developers to begin building DApps on a blockchain. Such apps require new ways of thinking about how to build, maintain, and deploy software. This tutorial serves as a complete working prototype of a DApp, motivated by a real use case in biomedical research requiring data privacy. We describe the architecture of a DApp, the implementation details of a smart contract, a sample iPhone operating system (iOS) DApp that interacts with the smart contract, and the development tools and libraries necessary to get started. The code necessary to recreate the app is publicly available.