This research intended to understand the factors affecting the acceptance of Bitcoin technology in Indonesia. It adopted the model of Unified Theory of Acceptance and Use of Technology (UTAUT), which took into account four influencing factors. Those were performance expectancy, effort expectancy, social influence, and facilitating conditions. The factors of gender and age were assumed to moderate the relations between those four factors and use and behavioral intention. The empirical data for those factors were collected by questionnaires from 49 respondents. The statistical significance of the relationships was evaluated by multivariate regression analysis. The result is a model that matches the data with R2 = 0,678. It demonstrates a high level of fitness. The analysis suggests that the performance expectancy factor and the social influence factor greatly affect the behavioral intention to use Bitcoin with the values of t-statistic of 3,835 (p-value = 0,000) for the former factor and 1,948 (0,059) for the latter factor. However, the social influence factor has less profound effect on the behavioral intention.
Roberto Frota Décourt, Usman W. Chohan, Maria Letizia Perugini
Esta investigación verifica si el efecto lunes que se encuentra en los mercados de acciones y letras del Tesoro también se produce en el mercado de Bitcoin, que difiere profundamente de otros mercados porque nunca se cierra. Una posible explicación para el efecto lunes es que la negociación del lunes ocurre después de uno o más días sin ninguna transacción. Se usó la prueba t-Student para verificar si los retornos diarios promedio de cada día de la semana son significativamente diferentes de otros días y encontramos que los retornos del lunes son significativamente más altos que en otros días. Después de eso, estimamos un modelo de regresión para confirmar que el retorno promedio del lunes es positivo y superior al promedio de otros días y se confirmó.
Crptocurrency is a type of digital currency that using decentralized method for validating transaction. In the same time, the user of the Bitcoin is protected using hash algorithm. The value of Bitcoin is increased sharply in 2017 that creates much attention from investors. The objective of this study is to develop the mathematical model evaluate growth of Bitcoin exchange rate. The data selected in this study are starting from 1st January 2017 until 10th December 2017. This study validates the normality distribution of data using graphical and numerical method. Graphical method indicates the first difference of data distribution is a non-normal distribution. Then, Shapiro-Wilk statistical test confirmed that first difference of data distribution deviate from normal distribution. The non-normal distribution occurs because of the presence of outliers. Next, this study validates the mathematical modeling fordata trend using quadratic formula. Result indicates that the growth of Bitcoin exchange rate in moving towards non-equilibrium point. This concludes that the growth of the Bitcoin exchange rate is in unstable region. The contribution of this study is to help investors to understand the nature of Bitcoin exchange rate. This study performed analysis that helps investors to develop more efficient investment portfolio in gaining better profit and reducing loss
Off-chain transaction channels represent one of the leading techniques to scale the transaction throughput in cryptocurrencies. However, the economic effect of transaction channels on the system has not been explored much until now. We study the economics of Bitcoin transaction channels, and present a framework for an economic analysis of the lightning network and its effect on transaction fees on the blockchain. Our framework allows us to reason about different patterns of demand for transactions and different topologies of the lightning network, and to derive the resulting fees for transacting both on and off the blockchain. Our initial results indicate that while the lightning network does allow for a substantially higher number of transactions to pass through the system, it does not necessarily provide higher fees to miners, and as a result may in fact lead to lower participation in mining within the system.
Bitcoin, 2009 yılında ortaya çıkan ve ardından sayısız kripto para biriminin dolaşıma girmesine zemin hazırlayan yenilikçi bir dijital para birimidir. Bitcoin; sahip olduğu market kapitalizasyonu, gün geçtikçe artan işlem adeti ve hacmi, zaman içinde daha stabil hale gelen piyasa değeri ile daha fazla birey tarafından kullanılan bir varlık haline gelmiştir. Bitcoin teknik olarak, "blok zinciri" adı verilen tüm işlemleri kapsayan ve kullanıcının bilgisayarının bir işlemin geçerliliğini doğrulamasına izin veren bir altyapı kullanır. Finansal anlamda ise Bitcoin, paranın değişim aracı olma, hesap birimi olma, vadeli işlemlerde ödeme aracı olma ve servet biriktirme aracı olma gibi temel fonksiyonlarını bir şekilde yerine getiren bir varlıktır. Bitcoin aynı zamanda, paranın basılması sürecinde madencilik ( mining ), paranın bireysel ve kurumsal hesaplarda korunumunu sağlayan e-cüzdan uygulamaları, teknik altyapıya odaklanan ve/veya para biriminin değeri üzerine teknik analiz hizmeti sağlayan finansal hizmetler, paranın işlem görmesini sağlayan ve diğer para birimleri ile takasını sağlayan bir borsa işlevi gören değişim aracıları, para biriminin mal ve hizmetlerin alım satımında bir ödeme aracı olarak kullanılmasına imkan veren ödeme işlemcileri ve bu hizmetlerin birden fazlasını sunan şirketlerini içeren yeni bir ekonomi oluşturmuştur. Bu yeni ekonomi fırsatları da beraberinde getirmiş ve risk sermayesi yatırımlarını kendine çekmektedir. Bu çalışma, Bitcoin ve ona bağlı olarak oluşan alt-sektörlerin oluşturmuş olduğu yeni ekonomi hakkında bilgi vermeyi amaçlamaktadır. Bununla birlikte çalışma, bu yeni ekonominin geleceğine dair bir perspektif geliştirme amacını taşımaktadır ve bu konuda yapılacak ileriki çalışmalar için bir öncül çalışma olarak kullanılabilecektir.
Shelly Grossman, Ittai Abraham, Guy Golan-Gueta, Yan Michalevsky · 7 authors
Callbacks are essential in many programming environments, but drastically complicate program understanding and reasoning because they allow to mutate object's local states by external objects in unexpected fashions, thus breaking modularity. The famous DAO bug in the cryptocurrency framework Ethereum, employed callbacks to steal $150M. We define the notion of Effectively Callback Free (ECF) objects in order to allow callbacks without preventing modular reasoning. An object is ECF in a given execution trace if there exists an equivalent execution trace without callbacks to this object. An object is ECF if it is ECF in every possible execution trace. We study the decidability of dynamically checking ECF in a given execution trace and statically checking if an object is ECF. We also show that dynamically checking ECF in Ethereum is feasible and can be done online. By running the history of all execution traces in Ethereum, we were able to verify that virtually all existing contract executions, excluding these of the DAO or of contracts with similar known vulnerabilities, are ECF. Finally, we show that ECF, whether it is verified dynamically or statically, enables modular reasoning about objects with encapsulated state.
Bitcoin is promoted as decentralized cryptocurrency by using pseudonym to achieve anonymity. Unfortunately, numerous seminal works have demonstrated that Bitcoin only offers weak anonymity in practice. Indeed, the practical technologies of clustering and flow analysis are much effective for tracing Bitcoin transaction and thereby revealing the owner involved. Otherwise said, user's privacy in Bitcoin has been sadly degenerated to be linkable. In this paper, we propose a completely decentralized scheme that can provide full anonymity in Bitcoin. The idea behind the output is to exploit a secure escrow address, which is consensual by all the involved users. The escrow address is generated from the trick of cryptographically secure distributed key generation and can then be used for mixing transactions in Bitcoin. Our protocol is secure against malicious adversaries. The users can jointly perform the protocol and successfully accomplish the transaction without the help of any (trusted) third party and no extra fees. Besides, our proposal is completely compatible with the current Bitcoin architecture.
Open access
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Цель работы – проанализировать современные тенденции и состояние международного рынка ведущих криптовалют и оценить возможные перспективы их дальнейшего развития и интеграции в мировую финансовую систему.
 Результаты исследования. Ретроспективно прослежена история происхождения и становления Биткоина (Bitcoin), рассмотрены некоторые особенности «Блокчейн» («Blockchain»). Проанализированы положительные и отрицательные стороны работы с криптовалютами. Рассмотрена ближайшая по капитализации к Биткоину криптовалюта Эфир (Ethereum) и проанализированы основные различия между ними. На основе проведенного исследования сформирован прогноз о наиболее вероятном направлении развития рынка криптовалют на ближайшее будущее и о возможности их интеграции в мировую финансовую систему.
 Теоретическое значение исследования. Настоящее исследование и его результаты будут способствовать решению глобальной научной задачи – формированию научно-обоснованного мнения академической науки к новому феномену в экономике – криптовалютам и их роли в мировой финансовой системе.
 Оригинальность/ценность/научная новизна исследования. Работа является одной из немногих, посвященных новому явлению в экономике – криптовалютам; представлены авторские прогнозы о возможных направлениях дальнейшего развития рынка криптовалют.
 Перспективы дальнейших исследований. Настоящая работа открывает возможность дальнейших исследований в области рынка криптовалют, его дальнейшего развития и интеграции в мировую финансовую систему.
 Тип статьи – эмпирическая.
Santiago Bragagnolo, Henrique Rocha, Marcus Denker, Sté́phane Ducasse
Smart contracts are embedded procedures stored with the data they act upon.Debugging deployed Smart Contracts is a difficult task since once deployed, the code cannot be reexecuted and inspecting a simple attribute is not easily possible because data is encoded.In this technical report, we present SmartInspect to address the lack of inspectability of a deployed contract.Our solution analyses the contract state by using decompilation techniques and a mirror-based architecture to represent the object responsible for interpreting the contract state.SmartInspect allows developers and also end-users of a contract to better visualize and understand the contract stored state without needing to redeploy, nor develop any ad-hoc code.
A mathematical model for smart contracts for deployment of the initial coin offering (ICO), widely used on the Ethereum platform, is proposed. The analysis of dependence of the network capacity on such parameters as the transaction buffer size, the average transaction processing time, is performed. Evaluations are obtained of which parameters have the greatest impact on the capacity of Ethereum within the developed model.
We present the first formalisation of a blockchain-based distributed consensus protocol with a proof of its consistency mechanised in an interactive proof assistant.
Krovi Rajasekhar, Sri HarshiniYalavarthy, Sravani Mullapudi, M Gowtham
A Blockchain is a ledger of records. It originally came from the digital currency bitcoin. Its main features are transparency and accountability. For this we use chameleon hashing concept which uses a trapdoor key. Unless the trapdoor is used it is hard to find collisions. We can create collisions only if we know the trapdoor and can rewrite the block of data with the new redacted stored files in blocks are permanently recorded and cannot be modified. To overcome this, we use the new redaction capability and expand its usefulness for enterprises and also in financial sector. This could limit uses in financial sector for the services because this must require data to be changed or smashed, coding and transaction mistakes might happen, which can be undone through redaction. An unchangeable record is not useful for the applications that area used for blockchain. Wherever the blockchain is used, either for a code or data there should be a way to redact it in unavoidable situations. The constraints for redacting a blockchain should be strict and can be done with whole block. We use this redaction concept with the bitcoin technology, which is a person-to-person digital cash system.
Oğuzhan Ersoy, Zhijie Ren, Zekeriya Erkin, Reginald L. Lagendijk
Existing permissionless blockchain solutions rely on peer-to-peer propagation mechanisms, where nodes in a network transfer transaction they received to their neighbors. Unfortunately, there is no explicit incentive for such transaction propagation. Therefore, existing propagation mechanisms will not be sustainable in a fully decentralized blockchain with rational nodes. In this work, we formally define the problem of incentivizing nodes for transaction propagation. We propose an incentive mechanism where each node involved in the propagation of a transaction receives a share of the transaction fee. We also show that our proposal is Sybil-proof. Furthermore, we combine the incentive mechanism with smart routing to reduce the communication and storage costs at the same time. The proposed routing mechanism reduces the redundant transaction propagation from the size of the network to a factor of average shortest path length. The routing mechanism is built upon a specific type of consensus protocol where the round leader who creates the transaction block is known in advance. Note that our routing mechanism is a generic one and can be adopted independently from the incentive mechanism.
Distributed ledger technologies (DLTs) are receiving much attention. As discussion focuses on the potential applications of DLTs, Blockchain-as-a-Service (BaaS) offerings are emerging to provide the underlying supporting infrastructure. BaaS entails a provider supplying and managing aspects of a DLT infrastructure to facilitate and bring efficiencies regarding the development, experimentation, deployment, and the ongoing management of DLT applications. However, much of the interest in DLTs stems from their potential to decentralise, disintermediate, and enable ‘trustless’ interactions. At first sight, BaaS – being offered by a provider – appears to run counter to this. In practice, whether BaaS raises substantive trust concerns depends on the nature of the offering, the application’s specifics, and the participants’ goals and risk appetite. This paper elaborates the nature of BaaS offerings, exploring the role of the provider as part of a wider infrastructure, and related issues of trust.
In the modern era, the digital currency or "crypto-currency" is developed rapidly. The most famous and large-scale digital payment system is bitcoin, the operation of which is based on modern blockchain technology. This crypto currency was invented by Satoshi Nakamoto in 2008. Nowdays, this system operates in many countries in the world, and the number of such countries is growing every year.
Bitcoin has emerged as a popular digital currency and arouses the interest not only of programmers, but also of investors and academics. What interests them most is its underlying technology, the blockchain. This thesis aims at giving an overview of the current state of cryptocurrencies and compares their different designs and approaches to Bitcoin. The blockchain technology will be explained, as well as how it could impact many aspects in life by showcasing different applications of Ethereum blockchain-based smart contracts. Based on the evaluation of the different cryptocurrencies and preceding conclusions, specific cryptocurrencies will be applied to the Tasklet system before proposing the implementation of the blockchain technology in such a system, in order to establish a reward system. The paper reviews a heterogeneous, scattered body of knowledge including academic literature, but also non-scientific sources due to the constantly evolving technology. On this basis, the advantages of Bitcoin, but also its weaknesses, as well as the vast potential of blockchain are discussed. Results indicate that although Bitcoin’s framework may be limited, it will still play an important role in the future due to its dominance in the cryptocurrency market. The short display of blockchain-fueled applications and its effects has shown its potential to transform the internet, leading to the rise of the Web 3.0. Keywords: Bitcoin, Blockchain, Cryptocurrency, Distributed Ledger Technology, Smart Contract
Purpose The real estate world finds itself at a tipping point of a transition: a dramatic and irreversible shift in (real estate) systems in society. This paper is a State of the art of Disruption, Blockchain and Real Estate in the Netherlands and international. Design/methodology/approach The following questions were asked to all those involved: What do you think is the essence of Blockchain for real estate? What is the most current situation with respect to Blockchain and real estate from your perspective? Which publications are important from your perspective? What do you expect with respect to the impact of Blockchain on real estate for (social) real estate? What are questions for the future for real estate and Blockchain? In addition, interviews, exploratory conversations and correspondence took place, and the content was peer reviewed. Findings Changes in value concepts affect the valuation of real estate and the thinking about it. The orientation of changing users and owners of real estate affects innovativeness, values and flexibility in managing that property. Orientation on disruption must be seen as proof that the real estate world is able to actually innovate the accumulated assets and consolidate this. The financial and real estate markets are markets that exaggerate through irrational behaviour. Fear of “eat or be eaten” determines people’s behaviour. Financial and thus real estate markets are always unstable and must always be regulated by people and organizations. Research limitations/implications The question that remains is whether it is important to look at disruptive innovations in existing markets or newcomers in the real estate market and Blockchain. The question is whether Blockchain is only a technological disruption, or a real game changer, and whether the entire value chain of the real estate market will embrace it. No two disruptions are the same. Trust in Blockchain is a prerequisite for guiding the predictable form of that disruption where start-up companies use new technology to offer cheaper and inferior alternatives to real estate in the market. You could also talk about anti-fragile value: “Some things benefit from shocks; they thrive and grow when exposed to volatility, randomness, disorder, and stressors and love adventure, risk, and uncertainty. Yet, in spite of the ubiquity of the phenomenon, there is no word for the exact opposite of fragile. Let us call it antifragile” (Taleb, 2012), in other words: attention to disruption and Blockchain creates a viable real estate economy. Practical implications The true meaning of the Blockchain technology for real estate still needs to be investigated. The author is still curious to understand and clarify the value of Blockchain for real estate processes. Doubt continues to exist and is therefore a feeding ground for further research, because we do not know what we have not seen. Social implications Looking at the impact of Blockchain on real estate, a number of conclusions can be drawn. First of all, the relationship between Blockchain and real estate has not yet been proven in practice. It is expected to develop further in the form of registering transaction processes and the DNA passport of a real estate object. Secondly, completeness and transparency are the basic ingredients for trust in the system. Third, real estate wants to remain viable. For this reason, taking the offense is necessary for real estate and management to connect with social demand. Behaviour also leads to new earnings models of the social and economic spin-off of disruptive real estate. If the Dutch real estate sector embraces Blockchain and is able to realize innovations, there are opportunities for real estate entrepreneurs to exploit the disruptive character to provide those new services. Originality/value The way in which disruption, Blockchain and real estate will develop in the coming years are not the only obvious characteristics of a particular era but also its social impact and user behaviour. This also applies to how this real estate transition can best be tracked, guided and utilized in society at the international, national and regional level. Disruptive organizations clearly respond to the viability of the (built) environment and therefore determine competitive strength. This affects the current and future valuation of real estate.
This paper examines the movement of cryptocurrencies’ return based on price. This volatility can spread to others of the same kind. Currently, the more cryptocurrencies are traded in market, the more chances are available for investors. The author wonders whether contagion risk among these cryptocurrencies happens or not in the event of crashing. We also introduce one empirical evidence of the mutual influence on these cryptocurrencies using Copulas approach. The findings show that all pairs have the structure dependence with Kendall-plots, particularly strong left tail dependence with Chi-plots. It also means the existence of contagion risk among these cryptocurrencies. The three methodologies namely Kendall-plots, Chi-plots and Copulas estimation produce consistent results. Therefore, the investors should carefully perform portfolio diversification to avoid contagious phenomenon.
Taylor C. Nelms, Bill Maurer, Lana Swartz, Scott Mainwaring
The payments industry – the business of transferring value through public and corporate infrastructures – is undergoing rapid transformation. New business models and regulatory environments disrupt more traditional fee-based strategies, and new entrants seek to displace legacy players by leveraging new mobile platforms and new sources of data. In this increasingly diversified industry landscape, start-ups and established players are attempting to embed payment in ‘social’ experience through novel technologies of accounting for trust. This imagination of the social, however, is being materialized in gated platforms for payment, accounting, and exchange. This paper explores the ambiguous politics of such experiments, specifically those, like Bitcoin or the on-demand sharing economy, that delineate an economic imaginary of ‘just us’ – a closed and closely guarded community of peers operating under the illusion that there are no mediating institutions undergirding that community. This provokes questions about the intersection of payment and publics. Payment innovators’ attenuated understanding of the social may, we suggest, evacuate the nitty-gritty of politics.
Blockchain ledgers and the Cloud are a perfect match. On the one hand, there is an inherent requirement for multiple separate authentication nodes to validate every Blockchain transaction with each node requiring substantial encryption calculation capability. On the other hand, massive economies of scale can bring down the cost per transaction, and provide service continuity. Additionally, the Cloud provides a perfect incubator for proof-of-concept projects. This paper considers the future implications of Blockchain, as the concept of disintermediated trustless ledgers stimulates the imagination of computer scientists and innovators. The Cloud’s role in implementing this new paradigm is also highlighted, as a new decentralized P2P-Cloud model. Finally, this paper discusses how Blockchain may be integrated into the university level computer science and information technology curriculum.
Scientific funding within the academy is an often complicated affair involving disparate and competing interests. Private universities, for instance, are vastly outpacing public institutions in garnering large, prestigious, science-related grants and external research investment. Inequities also extend to the types of research funded, with government, corporate, and even military interests privileging certain types of inquiry. This article proposes an innovative type of science research fund using cryptocurrencies, a fast-growing asset class. Although not a total funding solution, staking coins, specifically, can be strategically invested in to yield compound interest. These coins use masternode technologies to collateralize the network and speed transaction pace and may pay dividends to masternode holders, allowing institutions that purchase these types of central hubs to potentially engage in a lucrative form of dividend reinvestment. Using cryptocurrencies as a new funding stream may garner large amounts of capital and creation of nonprofit institutes to support the future of funding scientific research within educational institutions.
This paper reviews what stage the central banks of the world’s leading economies are at in their study and adoption of distributed ledger technology (DLT) to reengineer their various systems and functions. A brief description of DLT will be given, followed by an analysis of central banks’ publications and pronouncements to determine what each central bank is doing on their journey to DLT adoption. It was found that of the central banks for which information was available, all of them have expressed interest in DLT and have evaluated it to some extent. Nevertheless, no central bank has an operational DLT-based system at this point. This is because some issues remain regarding the speed, cost of processing, security, transparency and privacy, legal settlement finality, scalability and network effects of the technology. As DLT matures, the expectation is that these issues will begin to be resolved.