Blockchain Papers

Dominic Chalmers, Russell Matthews, Amy Hyslop

No abstract is available for this record.

Iago Sestrem Ochôa, Rafael Alexandre Piemontez, Lucas M. C. e Martins, Valderi Reis Quietinho Leithardt · 5 authors

Blockchain technology has aroused the interest of researchers as it ensures security and privacy in decentralized applications. One of the platforms currently used for the development of new blockchain-based solutions is the Ethereum network. This article presents an experimental analysis of the scalability of this network to identify its cost and performance for several contracts in a simulated private Ethereum network. The results obtained demonstrate that storage operations for large amounts of data can prevent the use of blockchain due to the high cost of gas charged for this type of operation. The experiments also pointed out that processing operations which do not store information have a small cost of gas.

Yoshitomi Eduardo Maehara Aliaga, Diego Fernandes Gonçalves Martins, Marco Aurélio Amaral Henriques

Neste trabalho apresentamos uma proposta mecanismo de consenso para blockchain baseado em PoS, que viabiliza a participação de usuários de uma maneira mais justa. Através da utilização de tempo discreto o protocolo utiliza rodadas, onde apenas participantes que passaram no desafio da rodada possam gerar o bloco. O protocolo garante uma participação mais igualitária pois não é possível gerar o bloco antes da próxima rodada esperada.

Nidhaleddine Ben Cheikh, Younes Ben Zaied, Julien Chevallier

No abstract is available for this record.

Mohammad Bayani Khaknejad

Bitcoin is a decentralized peer to peer digital transactions system that was introduced in 2009 in the aftermath of the financial crisis. Since its introduction, it has had a volatile journey, being adopted by computer programmers, cyber punk enthusiasts, criminals, and financial investors. While the future of bitcoin is still not clear, it has been widely adopted by many, not necessarily as a new method of transactions, but rather as a new investment vehicle. Being a new asset class, there are many unknown financial characteristics to be investigated about bitcoin and in this dissertation, we try to explore two of these characteristics: Price and volume. In the first essay, we investigate the price-volume relationship. The term “price-volume relationship” in the finance literature, usually implies either relationship between volume and the magnitude of return, or relationship between volume and return per se. It has been established by previous studies that volume is positively related to the magnitude of return. We document that this is the case for bitcoin as well, and that this is merely because of the resampling of observations. The relationship between volume and return per se, however, is more controversial. It has not been studied as heavily and it is mostly observed only in spot markets, which has led scholars to believe it is caused by the restrictions imposed on short- selling in spot markets. We examine this relationship in bitcoin spot and futures markets and argue that while it is only observed in the spot market, the absence of short-selling cannot be the reason for this relationship. In the second essay, we use market sentiment measures derived from a lexical analysis of news platforms and social media networks to try and forecast returns. We find that our sentiment measures do indeed granger-cause returns in the spot market. However, they do not explain much variation in returns, and therefore are not useful in forecasting prices in the absence of a fundamental model. This relationship is weaker in the futures market which is due to the higher level of investor sophistication in that market. We also examine the effect of our sentiment measures on volatility of returns, and on trading volume and find that they do drive these variables as well.

Sushrut Thorat, Daria Proklova, Marius V Peelen

The principles underlying the animacy organization of the ventral temporal cortex (VTC) remain hotly debated, with recent evidence pointing to an animacy continuum rather than a dichotomy. What drives this continuum? According to the visual categorization hypothesis, the continuum reflects the degree to which animals contain animal-diagnostic features. By contrast, the agency hypothesis posits that the continuum reflects the degree to which animals are perceived as (social) agents. Here, we tested both hypotheses with a stimulus set in which visual categorizability and agency were dissociated based on representations in convolutional neural networks and behavioral experiments. Using fMRI, we found that visual categorizability and agency explained independent components of the animacy continuum in VTC. Modeled together, they fully explained the animacy continuum. Finally, clusters explained by visual categorizability were localized posterior to clusters explained by agency. These results show that multiple organizing principles, including agency, underlie the animacy continuum in VTC.

Xu Wang, Guangsheng Yu, Xuan F. Zha, Wei Ni · 8 authors

No abstract is available for this record.

David Allen, James Aselta, Russell Engel

This paper examines the risks, accounting practices and disclosures of companies who accept cryptocurrency for the payment of products or services. We provide a brief history of cryptocurrency and blockchain technology that allows the reader to deepen their understanding of the subject before moving on to a discussion of how regulatory bodies such as the Financial Accounting Standards Board (FASB), the Securities and Exchange Commission (SEC) and the Internal Revenue Service (IRS) are treating the accounting for cryptocurrency transactions.

Michael Coblenz, Reed Oei, Tyler Etzel, Paulette Koronkevich · 9 authors

Blockchain platforms are coming into broad use for processing critical transactions among participants who have not established mutual trust. Many blockchains are programmable, supporting smart contracts, which maintain persistent state and support transactions that transform the state. Unfortunately, bugs in many smart contracts have been exploited by hackers. Obsidian is a novel programming language with a type system that enables static detection of bugs that are common in smart contracts today. Obsidian is based on a core calculus, Silica, for which we proved type soundness. Obsidian uses typestate to detect improper state manipulation and uses linear types to detect abuse of assets. We describe two case studies that evaluate Obsidian's applicability to the domains of parametric insurance and supply chain management, finding that Obsidian's type system facilitates reasoning about high-level states and ownership of resources. We compared our Obsidian implementation to a Solidity implementation, observing that the Solidity implementation requires much boilerplate checking and tracking of state, whereas Obsidian does this work statically.

Yue Zhang, Jian Weng, Jiasi Weng, Ming Li · 5 authors

With the popularity of Blockchain comes grave security-related concerns. Achieving privacy and traceability simultaneously remains an open question. Efforts have been made to address the issues, while they may subject to specific scenarios. This paper studies how to provide a more general solution for this open question. Concretely, we propose Onionchain, featuring a suite of protocols, offering both traceability and privacy. As the term implies, our Onionchain is inspired by Onion routing. We investigate the principles of Onion routing carefully and integrate its mechanism together with Blockchain technology. We advocate the Blockchain community to adopt Onionchain with the regards of privacy and traceability. To this end, a case-study of Onionchain, which runs in the context of Vehicular Ad Hoc Networks (VANETs), is proposed, providing the community a guideline to follow. Systematic security analysis and extensive experiments are also conducted to validate our secure and cost-effective Onionchain.

Wonsup Shin, Seok-Jun Bu, Sung-Bae Cho

The autonomous trading agent is one of the most actively studied areas of artificial intelligence to solve the capital market portfolio management problem. The two primary goals of the portfolio management problem are maximizing profit and restrainting risk. However, most approaches to this problem solely take account of maximizing returns. Therefore, this paper proposes a deep reinforcement learning based trading agent that can manage the portfolio considering not only profit maximization but also risk restraint. We also propose a new target policy to allow the trading agent to learn to prefer low-risk actions. The new target policy can be reflected in the update by adjusting the greediness for the optimal action through the hyper parameter. The proposed trading agent verifies the performance through the data of the cryptocurrency market. The Cryptocurrency market is the best test-ground for testing our trading agents because of the huge amount of data accumulated every minute and the market volatility is extremely large. As a experimental result, during the test period, our agents achieved a return of 1800% and provided the least risky investment strategy among the existing methods. And, another experiment shows that the agent can maintain robust generalized performance even if market volatility is large or training period is short.

Byoungjin Seok, Jinseong Park, Jong Hyuk Park

Blockchain is a technology that can ensure data integrity in a distributed network, and it is actively applied in various fields. Recently, blockchain is gaining attention due to combining with the Internet of Things (IoT) technology in the industrial field. Moreover, many researchers have proposed the Industrial IoT (IIoT) architecture with blockchain for data integrity and efficient management. The IIoT network consists of many heterogeneous devices (e.g., sensors, actuators, and programmable logic controllers (PLC)) with resources-constrained, and the availability of the network must be preferentially considered. Therefore, applying the existed blockchain technology is still challenging. There are some results about the technique of constructing blockchain lightly to solve this challenge. However, in these results, the analysis in perspective of cryptographic performance (area, throughput, and power consumption) has not been considered sufficiently, or only focused on the architecture of the blockchain network. The blockchain technology is based on cryptographic techniques, and the main part is a cryptographic hash function. Therefore, if we construct the blockchain-based IIoT architecture, we have to consider the performance of the hash function. Many lightweight hash functions have been proposed recently for the resource-constrained environment, and it can also be used to the blockchain. Therefore, in this paper, we analyze the considerations of lightweight blockchain for IIoT. Also, we conduct an analysis of lightweight hash for blockchain, and propose a new lightweight hash-based blockchain architecture that can change the hash algorithm used for mining adjust to network traffic.

Zvezdin Besarabov, Todor Kolev

Creating efficient deep neural networks involves repetitive manual optimization of the topology and the hyperparameters. This human intervention significantly inhibits the process. Recent publications propose various Neural Architecture Search (NAS) algorithms that automate this work. We have applied a customized NAS algorithm with network morphism and Bayesian optimization to the problem of cryptocurrency predictions, where it achieved results on par with our best manually designed models. This is consistent with the findings of other teams, while several known experiments suggest that given enough computing power, NAS algorithms can surpass state-of-the-art neural network models designed by humans. In this paper, we propose a blockchain network protocol that incentivises independent computing nodes to run NAS algorithms and compete in finding better neural network models for a particular task. If implemented, such network can be an autonomous and self-improving source of machine learning models, significantly boosting and democratizing the access to AI capabilities for many industries.

Naveed UL Hassan, Chau Yuen, Dusit Niyato

In this paper, we discuss the integration of blockchain in smart energy systems. We present various blockchain technology solutions, review important blockchain platforms, and several blockchain based smart energy projects in different smart energy domains. The majority of blockchain platforms with embedded combination of blockchain technology solutions are computing- and resource- intensive, and hence not entirely suitable for smart energy applications. We consider the requirements of smart energy systems and accordingly identify appropriate blockchain technology solutions for smart energy applications. Our analysis can help in the development of flexible blockchain platforms for smart energy systems.

Zoltán Lux, Felix Beierle, Sebastian Zickau, Sebastian Göndör

Self-sovereign Identity (SSI) powered by distributed ledger technologies enables more flexible and faster digital identification workflows, while at the same time limiting the control and influence of central authorities. However, a global identity solution must be able to handle myriad credential types from millions of issuing organizations. As metadata about types of digital credentials is readable by everyone on the public permissioned ledger with Hyperledger Indy, anyone could find relevant and trusted credential types for their use cases by looking at the records on the blockchain. To this date, no efficient full-text search mechanism exists that would allow users to search for credential types in a simple and efficient fashion tightly integrated into their applications. In this work, we propose a full-text search framework based on the publicly available metadata on the Hyperledger Indy ledger for retrieving matching credential types. The proposed solution is able to find credential types based on textual input from the user by using a full-text search engine and maintaining a local copy of the ledger. Thus, we do not need to rely on information about credentials coming from a very large candidate pool of third parties we would need to trust, such as the website of a company displaying its own identifier and a list of issued credentials. We have also proven the feasiblity of the concept by implementing and evaluating a prototype of the full-text credential metadata search service.

Weizhao Tang, Weina Wang, Giulia Fanti, Sewoong Oh

Payment channel networks (PCNs) are viewed as one of the most promising scalability solutions for cryptocurrencies today. Roughly, PCNs are networks where each node represents a user and each directed, weighted edge represents funds escrowed on a blockchain; these funds can be transacted only between the endpoints of the edge. Users efficiently transmit funds from node A to B by relaying them over a path connecting A to B, as long as each edge in the path contains enough balance (escrowed funds) to support the transaction. Whenever a transaction succeeds, the edge weights are updated accordingly. In deployed PCNs, channel balances (i.e., edge weights) are not revealed to users for privacy reasons; users know only the initial weights at time 0. Hence, when routing transactions, users typically first guess a path, then check if it supports the transaction. This guess-and-check process dramatically reduces the success rate of transactions. At the other extreme, knowing full channel balances can give substantial improvements in transaction success rate at the expense of privacy. In this work, we ask whether a network can reveal noisy channel balances to trade off privacy for utility. We show fundamental limits on such a tradeoff, and propose noise mechanisms that achieve the fundamental limit for a general class of graph topologies. Our results suggest that in practice, PCNs should operate either in the low-privacy or low-utility regime; it is not possible to get large gains in utility by giving up a little privacy, or large gains in privacy by sacrificing a little utility.

Svetlana Egorova, L A Yudanova, V. A. Budasova

In the digital economy, the strengthening of the role of socially oriented non-profit organisations (NPOs) in addressing issues related to the harmonization of the social and economic aspects of society development, cannot be achieved without refocusing accounting on the solution of strategic tasks. An important tool of strategic planning and accounting in order to attract and monitor the use of earmarked funds — is budgeting, which had not been adequately reflected in the accounting activities of socially oriented NPOs. The organization of budgeting system in socially oriented non-profit organizations is based on the following characteristics: the problem of selection of calculation units; a high level of uncertainty of a profitable part of the budget, which is financed by revenues from basic and associate activities; the social orientation of the non-profit organizations, which defines the enhanced responsibility for performance and requires the clarification of the concept of operations results in itself. In the socially oriented NPO, the use of the result-oriented budgeting model, in which the expenditure of trust funds is administered in accordance with the principle of centralization on the one hand, and on the other hand, the objectives are achieved on the basis of the principles of decentralization, ensures planning, execution and monitoring of budget expenditures in direct connection with the specified, and achievable results. Under this model, the mobile annual budgets with a step equal to one month’s budgeting are used. Budget performance analysis aims to assess the quality of socially oriented non-profit organizations’ performance, which have a double-sided nature: on the one hand, the Organization’s efforts are evaluated, and on the other hand, the task force is evaluated. The effect of earmarked funds’ use becomes visible in subsequent reporting periods and is determined with regard to socially oriented NPOs within the society.

Irina Yarygina, O. A. Borovikova

The subject of the research is the BRICS countries activities. The purpose of the work is to assess the initiatives for creating the intergovernmental cooperation format BRICS+ as a factor of economic development of member states, as well as to suggest ways of the interaction mechanism perfection in the fields of trade, investments, multilateral cooperation of development banks, creating international financial centers and payment systems and making use of national currencies in mutual settlements. It is concluded that it is necessary to form favorable conditions for cooperation within new regional associations with the leading role of Russia, India and China. The urgency of the research lies in the fact that the assessment of achievements and prospects of the countries in the spheres of finance, trade and investments presented in the research allows to draw a conclusion about a positive character of the initiative to create the intergovernmental cooperation format BRICS+ and about advisability to expand multilateral interactions through trade agreements with mutual settlements in national currencies of partner countries, through simplification of investment mechanisms and their respective financial provision, primarily in financing major infrastructural projects that have an integration effect. The authors argue for the importance to create a decentralized integration model of interaction for parties via cooperating of a bigger number of participants, which will enable developing countries to meet global challenges and to solve developmental problems effectively. The authors also emphasize that the creation of BRICS+ is a significant initiative that will contribute to fulfilling the tasks formulated in the President of the Russian Federation V. V. Putin Decree “About national goals and strategic objectives of the RF development for the period till 2024” and in his message to the Federal Assembly on 20.02.2019.

Mark Fenwick, Erik P. M. Vermeulen

Advocates of blockchain believe that distributed ledger technologies can provide us with a technological infrastructure to challenge the concentrated power of tech giants such as Amazon, Facebook and Google, and create a more equitable, sustainable and decentralized world. This paper considers these claims and concludes that they are preferable to defending the status quo or arguing that a solution might be found in more and better regulations. Nevertheless, the future remains highly uncertain and we are currently living in a rapidly evolving “space” between two competing realities: a centralized old-world reality and a fast-emerging, but, as yet, incomplete, decentralized reality. We remain optimistic that decentralization is coming but identify powerful competing forces seeking to preserve the status quo. As such, we must encourage more organizations – business, government, investors, charities – to experiment with distributed ledger technologies and to participate actively in the digital transformation. We need more experimentation to address the current shortcomings of decentralisation and to ensure the early arrival of mainstream applications of a technology that has the potential to solve some of the most pressing global challenges of a digital age.

Lisa Morhaim

Blockchain technology is bringing together concepts and operations from several fields, including computing, communications networks, cryptography, and has broad implications and consequences thus encompassing a wide variety of domains and issues, including Network Science, computer science, economics, law, geography, etc. The aim of the paper is to provide a synthetic sketch of issues raised by the development of Blockchains and Cryptocurrencies, these issues are mainly presented through the link between on one hand the technological aspects, i.e. involved technologies and networks structures, and on the other hand the issues raised from applications to implications. We believe the link is a two-sided one. The goal is that it may contribute facilitating bridges between research areas.

Zoltán Lux, Felix Beierle, Sebastian Zickau, Sebastian Göndör

Self-sovereign Identity (SSI) powered by distributed ledger technologies\nenables more flexible and faster digital identification workflows, while at the\nsame time limiting the control and influence of central authorities. However, a\nglobal identity solution must be able to handle myriad credential types from\nmillions of issuing organizations. As metadata about types of digital\ncredentials is readable by everyone on the public permissioned ledger with\nHyperledger Indy, anyone could find relevant and trusted credential types for\ntheir use cases by looking at the records on the blockchain. To this date, no\nefficient full-text search mechanism exists that would allow users to search\nfor credential types in a simple and efficient fashion tightly integrated into\ntheir applications. In this work, we propose a full-text search framework based\non the publicly available metadata on the Hyperledger Indy ledger for\nretrieving matching credential types. The proposed solution is able to find\ncredential types based on textual input from the user by using a full-text\nsearch engine and maintaining a local copy of the ledger. Thus, we do not need\nto rely on information about credentials coming from a very large candidate\npool of third parties we would need to trust, such as the website of a company\ndisplaying its own identifier and a list of issued credentials. We have also\nproven the feasiblity of the concept by implementing and evaluating a prototype\nof the full-text credential metadata search service.\n

Catherine Thompson

OPINION article Front. Blockchain, 06 September 2019Sec. Blockchain for Good Volume 2 - 2019 | https://doi.org/10.3389/fbloc.2019.00011

Authors unavailable

In the Internet of Things (IoT) idea, regular gadgets end up savvy and self-governing. As we are seeing idea behind this is transforming into a realism on account of achievement in innovation, but we still face challenges, especially in some field like security e.g., information dependability. Taking account, the upcoming advancement in the field of IoT, it seems very important to give trust in the field of enormous approaching data foundation. Blockchain has given us the new way to share our data with others. Building such a trust in discrete condition with is term as the key factor of blockchain in which we don’t need any specialists is a hi-tech development that can possibly change numerous enterprises, the IoT among them. Troublesome advances, for example, IoT used enormous information and distributed to beat its restrictions, and we blockchain can be one of the accompanying ones. This paper centers around this correlation, explores difficulties in blockchain with IoT implementation, and reviews recent significant work so as to investigate about how the existing blockchain technology can change the way we work in IoT.

Nada Mouchfiq, Ahmed Habbani, Chaimae Benjbara

The security aspect of the IoT occupies a place of great importance especially after the evolution that has known this field lastly because it must take into account the transformations and the new applications .Blockchain is a new technology dedicated to the data sharing. However, this does not work the same way in the different systems with different operating principles. This article will discuss network security using the Blockchain to facilitate the sending of messages and information, enabling the use of new processes and enabling autonomous coordination of devices. To do this, we will discuss proposed solutions to ensure a high level of security in these networks in the work of other researchers. Finally, our article will propose a method of security more adapted to our needs as a team working in the ad hoc networks, this method is based on the principle of the Blockchain and that we named ”MPR Blockchain”.