Anja Meironke, Tobias Seyffarth, Johannes Damarowsky
Second generation blockchain technologies such as Ethereum can be used not only for financial transactions but also for cross-organizational processes, for applications in the pharmaceutical industry and even in the field of Business Process Compliance (BPC). However, there are many challenges in the field of BPC. Thus, we raised the following research question: How does the Ethereum blockchain address challenges of BPC? To answer this question, we conducted a structured literature review to identify challenges in BPC as well as features of the Ethereum blockchain that may solve the selected BPC challenges. As a result, we identified 21 BPC challenges and categorized these into legal, organizational, human-centered, technical and economic challenges. We found that the technical and organizational BPC challenges were those that Ethereum could best solve, while human-centered challenges could be less well addressed. Furthermore, the implementation of the Ethereum blockchain leads to additional challenges, such as the immutability of illegal content within the Ethereum blockchain or the error-proneness and zero-defect tolerance of smart contracts.
The complex user onboarding experience is one of the main issues for achieving mass adoption in Ethereum. Users new to the space need to install a dedicated browser or extension, create and back up an account, and then acquire ETH just to begin interacting with a DApp. While in previous chapters we have worked with web3-enabled users, in this chapter we will look into ways for simplifying the onboarding experience for new ones.
This study examines and compares the volatility in sample fit and out of sample forecast of four different heteroscedasticity models, namely ARCH, GARCH, EGARCH and GJR-GARCH applied to Bitcoin, Ethereum and Ripple. The models are fitted over the period from 2016-01-01 to 2019-01-01 and then used to obtain one day rolling forecasts during the period from 2018-01-01 to 2019-01-01. The study investigates three different themes consisting of the modelling framework structure, complexity of models and the relation between a good in sample fit and good out of sample forecast. AIC and BIC are used to evaluate the in sample fit while MSE, MAE and R2LOG are used as loss functions when evaluating the out of sample forecast against the chosen Parkinson volatility proxy. The results show that a heavier tailed reference distribution than the normal distribution generally improves the in sample fit, while this generality is not found for the out of sample forecast. Furthermore, it is shown that GARCH type models clearly outperform ARCH models in both in sample fit and out of sample forecast. For Ethereum, it is shown that the best fitted models also result in the best out of sample forecast for all loss functions, while for Bitcoin non of the best fitted models result in the best out of sample forecast. Finally, for Ripple, no generality between in sample fit and out of sample forecast is found.
Tianlu Gao, Wei Gao, Jun Jason Zhang, Wenzhong David Gao
With the installed capacities of Distributed Generations (DGs) dramatically increasing in power systems from Distributed Energy Resources (DERs) such as hydropower, wind, solar, geothermal and biomass, the operation methods of DERs tradings or transactions become more and more complicated. However, the energy market of DERs in Microgrids (MGs) is still under devolvement due to low security and transparency at present. Therefore, a small-scale microgrid energy market is proposed in this study based on Decentralized Autonomous Organization of Parallel, Integrity, Longevity, and Transparency (PILT-DAO) of the features of the blockchain. The microgrid owners can complete the transaction in the PILT-DAO market. In order to implement this energy trading platform, the first step is to simulate a modified distributed IEEE 13 node test feeders system. The next step is to develop a price mechanism method based on a consensus + innovation distributed algorithm to calculate the distributed Distribution Locational Marginal Price (DLMP). At the meantime, smart meters record the Power Flow (PF) data of each DG as one node of the whole simulated distributed power system and send them to blockchain including distributed price and power generation data. The third step is to constitute a decentralized autonomous market by programming smart contracts in Ethereum DAO, running in an artificial system parallelly. A case study of a small-scale microgrid energy market based on PILT-DAO is illustrated followed by the conclusion.
Decentralised ledgers are a prime application case for consensus protocols. Changing sets of validators have to agree on a set of transactions in an asynchronous network and in the presence of Byzantine behaviour. Major research efforts focus on creating consensus protocols under such conditions, with proof-of-stake (PoS) representing a promising candidate. PoS aims to reduce the waste of energy inherent to proof-of-work (PoW) consensus protocols. However, a significant challenge is to get PoS protocols "right", i.e. ensure that they are secure w.r.t. safety and liveness. The "Correct-by-Construction" (CBC) Casper approach by the Ethereum project employs pen-and-paper proofs to ensure its security. CBC Casper is a framework to define consensus protocols and aims to prove safety without loss of abstractness. Each member of the CBC Casper family of protocols is defined by five parameters. CBC Casper models the protocol by a state of each validator and messages sent by validators. Each validator can transition its state using messages by other validators that include their current consensus value and a justification (i.e. their previous messages). We extend CBC Casper in three ways. First, we summarise the research of CBC Casper and extend the definitions of safety and liveness properties. To this end, we discuss an instance of CBC Casper called Casper The Friendly GHOST (TFG), a consensus protocol using a variant of the GHOST fork-choice rule. Second, we refine the properties of messages and states in CBC Casper and give a definition of blockchain safety for Casper TFG. Third, we formally verify the CBC Casper framework together with our refined message and state properties as well as our blockchain safety definition in the Isabelle/HOL proof assistant.
If you have been following the previous chapters, you should now have a pretty good understanding of Ethereum Smart Contracts and how to interact with them through the web3.js APIs.
In the previous chapter, you saw how to use web3.js to interact with your deployed Smart Contract. Using web3.js, you were able to connect to an Ethereum node (through MetaMask, or directly to an Ethereum node such as Ganache running locally on your computer). Using the document notarizer example, you were able to
An inclusive project is classified and alienated into several tasks where as task management is one of the foremost components of project management, since the roles and tasks assigned by the manager of this component to each employee working on a project. In scrupulous there are several ways to track the status of work and this monitoring is also required to find the efficiency of an individual and at the time of the annual and mid- term appraisal and all these monitoring records can be used to give qualifications to associates and employees. In this work, the authors have proposed a system along with the solution based on the ERC20 token which is identified as blockchain platform based on Ethereum in which they can implement Project Task Management which is tamper proof and as well as can track the assigned task of an employee on real time basis.
Функциональное моделирование на основе стандарта IDEF0 – создание графических моделей любой предметной деятельности, включающих иерархическое описание процессов, операций, ресурсов (информации), инструментария, исполнителей, управления и связей между ними. В статье предложена функциональная модель создания и управления смарт-контрактами на платформе Ethereum.
The 2008 debut of Bitcoin marked the first large-scale implementation of blockchain technology, and its decentralized approach to monetary systems has since been abstracted to more generalized purposes like distributed computing. Platforms like Ethereum, which function as a global, decentralized computing and data storage system, promise to bring the cost of decentralized knowledge production in line with the efficiencies afforded by the centralized, integrated computing systems that currently dominate the knowledge economy. Blockchain technologies have been investigated for a wide range of information management purposes, but their exploration within the realm of library and information studies has largely been nascent. Though many applications within the field have been envisioned, few have been explored in depth. Among the many functions performed in the field of librarianship, the work of cataloguers—which has always been performed in a decentralized manner—represents an intriguing use case. A review of current shared-cataloguing practices reveals that catalogues have become largely-centralized, divorced from public participation, dominated by an ethos of efficiency at the cost of quality, and essentially unaltered since the shift from physical to electronic catalogue storage more than 40 years ago. The evolution of blockchain technologies, paired with an intentional approach to shared catalogues that is open for use, transparency, and public participation, is explored in a conceptual framework and design based on the Ethereum platform. A theoretical design scheme grounded in the affordances of Ethereum, shaped by the principles of open source software development, and guided by the best practices of existing social information production systems results in a proposal for Catagora: an open source, open-for-use, transparent and participatory shared-cataloguing platform that reverses the trend towards architectural and political centralization and promises novel catalogue features such as complete revision history and distributed collaboration on the content and quality of catalogue entries. Blockchain technology, alone, cannot disrupt shared cataloguing practices; such a shift involves the voluntary and eager participation of cataloguers and members of the public in order to sustain and grow the system. The Catagora design concept presented in this thesis incorporates accessibility, collaboration and reputational systems that are intended to foster open participation, but these alone cannot guarantee a thriving, shared-cataloguing alternative to existing systems. Further exploration, in the form of a live implementation, is warranted; and lessons from existing large-scale library technology projects suggest that a centrally-coordinated implementation, targeting key cataloguing partners and driven by a passionate project champion, may provide a more complete picture of the blockchain’s potential to support open, shared cataloguing for the benefit of information seekers.
In early 2018 prices peaked at USD 20,000 and, almost two years later, we still continue debating if cryptocurrencies can actually become a currency for the everyday life or not. From the economic point of view, and playing in the field of behavioral finance, this paper analyses the relation between prices and the search interest on Bitcoin since 2014. We questioned the forecasting ability of Google Trends for the behavior of price by performing linear and nonlinear dependency tests, and exploring performance of ARIMA and Neural Network models enhanced with this social sentiment indicator. Our analyses and models are founded upon a set of statistical properties common to financial returns that we establish for Bitcoin, Ethereum, Ripple and Litecoin.
Rewriting-history attacks can erase all valid records of blockchain-based systems, which is extremely devastating. To deter such attacks, we design a new smart contract-based secure model to make such attacks ineffective. Each node who creates a new block is required to register with the smart contract to get a voucher required for the subsequent block validation. We introduce the design idea and the structure of the proposed model in detail. We also present the algorithms of the smart contract and analyze the security performance of the proposed model in different cases. To prove the feasibility of the proposed model, we use the Solidity language to implement the smart contract in this model and simulate it on the Ethereum test network. We also show simulation results in terms of runtime and resource consumption.
The keystone of information security has been access control. Very often, User data is misused and users are oblivious to the use of their data by unauthorized parties. Current strategies to provide storage for confidential data and subsequent authentication involve relying on a trusted third party for the same, which could be victims of Denial of Service (DoS) attacks or technical failures. This paper examines a strategy where the underlying framework for providing Access Control is the blockchain, hence decentralizing the mechanism of providing access control. Further in this paper, we demonstrate and model the User Data access on the Ethereum framework. Personal Information of the user by a website or an application is retrieved on a need-to-know basis from the off-blockchain, as determined by the user, the true owner of the data. Personal data is highly protected and the different permissions to different websites or applications are determined by the Smart Contract.
Karl Wüst, Loris Diana, Kari Kostiainen, Ghassan Karame · 6 authors
In this paper, our main goal is to design a solution that adds expressive smart contract execution support as a subsystem to existing legacy blockchain systems. The primary usage of our solution is to enhance systems like Bitcoin that have no built-in smart contract capabilities. The secondary usage is to extend the contract execution capabilities of platforms like Ethereum that support contracts but have severe limitations on the complexity of allowed computations.
Block-chain world is very dynamic and there is need for strong governance and underlying technology architecture to be robust to face challenges. This paper considers Ethereum, a leading block chain. We deep dive into the nature of this block chain, wherein for software upgrades forks are performed. They types of forks and impact is discussed. A specific Ethereum hack led to a hard fork and focus is provided on understanding the hack and overcoming it from a novel approach. The current model has been unable to handle multiple Ethereum attacks. Thus the current approach is compared against a novel approach providing a security and scaling solution. Here the architecture draws upon combining block-chain layers into operating system level. The approach can have tremendous benefits to block chain world and improve the way decentralized application teams perform. The benefits of the novel architecture is discussed. The approach helps safe guard block chain projects, making them safer and chain agnostic.
Current research has led to a rejection of the hypothesis of a normal distribution of financial assets returns. Under these conditions, portfolio variance cannot serve as a good risk measure. In this paper analyzed the daily returns of the most common cryptocurrencies: Bitcoin, Bitcoin Cash, Litecoin, XRP, Ethereum, NEM. It is shown that the asset returns are not normally distributed, but with good precision follow the Cauchy distribution. The analytical expressions for risk measure were obtained using the Cauchy distribution function and the VaR technique. The efficient frontiers of cryptocurrencies portfolios were constructed using modified Markowitz model. The purpose of the article is to assess the risks of major cryptocurrencies and to diversify the risk of cryptocurrency investing by applying a portfolio model