Cryptocurrencies, based on and led by Bitcoin, have shown promise as infrastructure for pseudonymous online payments, cheap remittance, trustless digital asset exchange, and smart contracts. However, Bitcoin-derived blockchain protocols have inherent scalability limits that trade-off between throughput and latency and withhold the realization of this potential. This paper presents Bitcoin-NG, a new blockchain protocol designed to scale. Based on Bitcoin's blockchain protocol, Bitcoin-NG is Byzantine fault tolerant, is robust to extreme churn, and shares the same trust model obviating qualitative changes to the ecosystem. In addition to Bitcoin-NG, we introduce several novel metrics of interest in quantifying the security and efficiency of Bitcoin-like blockchain protocols. We implement Bitcoin-NG and perform large-scale experiments at 15% the size of the operational Bitcoin system, using unchanged clients of both protocols. These experiments demonstrate that Bitcoin-NG scales optimally, with bandwidth limited only by the capacity of the individual nodes and latency limited only by the propagation time of the network.
<p>Bitcoin is a decentralized virtual crypto currency that has attracted attention from technologists, economists, consumers, regulators, black marketeers, venture capitalists and Wall Street commentators to name a few. While many debate issues such as whether or not bitcoin is money, how might it ultimately be regulated and whether or not it represents a truly disruptive innovation, this paper examines the current landscape of bitcoin and identifies some of the early adopters and significant events that have contributed to this unfolding phenomenon.</p>
In recent years, ideas about crypto currencies with interesting and new for today monetary principles becoming more and more popular. The crypto currencies' met different attitude to it new for the world finances principals. There are different talks. Ones think that it may improve monetary system, others think that it is a toy money that may cause instability and crash the world finance. However, the fact is that innovative concept of e-currency still developing and becoming more popular and in this way crypto currencies, particularly the most popular one-bitcoin is more useful and more preferable way of transaction in Internet. For today its audience accumulated a 9 billion USD on exchange stocks specially designed for crypto currency. The paper is about the new currency and about its innovative principles that can be used in current financial situation.
It doesn't matter whether its coin, banknotes or even gold the usual currency in circulation in our communities. But have we ever thought of using virtual currency in the real world, with a higher value to that of gold. Bitcoin have caused waves across the globe, it is believed to be the most valuable currency in the future. This article describes the sensation caused by the global virtual currency Bitcoin, the rise resulting in principle and practical instruction on how to get Bitcoin currently in use.
Bitcoin gains more and more attention in the general public and is already the most popular virtual currency. At the same time, the acceptance of Bitcoin as a speculative asset and also as a payment vehicle increases. This is an indication that we might now be entering an era of parallel currency systems. Therefore, one could state that the Bitcoin network and the central banking system could become two rival systems with respect to issuing payment vehicles and providing cross-border payment systems. Our aim is to analyse the central bank incentives for establishing a network model that includes hacking. With our model we are able to explain why central banks have no incentive to advance Bitcoin regulation at the current stage of development, as this would reduce the critical mass of Bitcoin users. Finally, in combination with a central bank loss function, we are able to calculate an optimal level of central regulation.
The Technology Acceptance Model (TAM) is an important analysis tool in the study of the social mechanisms of technology adoption, and has received considerable attention and study in the literature. Though empirical support for the model has varied depending on situation specifics, it remains a popular and useful conceptual framework for analysis of factors contributing to technology acceptance or rejection by the relevant constituencies. In this paper we use the TAM framework to analyze aspects of the technology acceptance process in the case of Bitcoin. Bitcoin is an entirely digital distributed currency whose disruptive and disintermediating nature has fueled the tremendous growth of the financial technology space over the past few years. Bitcoin's distributed, verifiable, and immutable public transaction ledger, the blockchain, holds out the promise of fast, cheap, peer-to-peer financial transactions, as well as significant efficiencies in the transfer of other assets via overlay networks. In this study, we break down, describe, and analyze the various factors affecting the past and future adoption curve for Bitcoin in the context of the Technology Acceptance Model.
The anonymity of the Bitcoin system has some shortcomings. Analysis of Transaction Chain (ATC) and Analysis of Bitcoin Protocol and Network (ABPN) are two important methods of deanonymizing bitcoin transactions. Nowadays, there are some anonymization methods to combat ATC but there has been little research into ways to counter ABPN. This paper proposes a new anonymization technology called Transaction Remote Release (TRR). Inspired by The Onion Router (TOR), TRR is able to render several typical attacking methods of ABPN ineffective. Furthermore, the performance of encryption and decryption of TRR is good and the growth rate of the cipher is very limited. Hence, TRR is suited for practical applications.
Open access
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cs.CR
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Peggy Valcke, Niels Vandezande, Nathan Van de Velde
The research looked at which third party payment providers (TPPâs) are covered by the PSD2 and AMLD4 directives, the consequences thereof, as well as to what extent such coverage goes; and sought to analyse the potential for the regulation of cryptocurrency in terms of combatting money laundering and terrorist financing. TPPâs gain possession of a significant amount of sensitive information, for instance by providing a gateway from which consumers log in to their bank accounts using their unique identifiers and credentials. As a result, these entities are drawing increasingly more attention from legislators and regulators.Under the framework of the PSD2, TPPâs will be subject to stringent regulatory standards similar to those placed on traditional payment service providers under the PSD. In the US, regulation of TPPâs must be assessed on a state-by-state basis. In Florida, for instance, they can be considered as money transmitters, thus putting them under that regulation, as well as the federal Bank Secrecy Act. In Asia, the number of TPPâs has grown significantly over the past years. In China, these actors are regulated by the Peopleâs Bank of China, and are subjected to a number of requirements similar to those found in the EU, such as minimum capital requirements and anti-money laundering rules.Another notable development is that of alternative payment methods â a prime example here are cryptocurrencies such as bitcoin. The bitcoin ecosystem is decentralized, meaning that no single entity controls the system. Currently, there exists no convincing arguments to consider virtual currencies as regulated under the EUâs Payment Services Directive or the Second E-money Directive. While the PSD2 does introduce new terminology and significantly amended scope exemptions compared to the original Payment Services Directive, there is no wider inclusion of virtual currencies under its scope. A similar argument can be made for the recently adopted AMLD4, where virtual currencies have been omitted from its scope despite earlier signs that this development may be included. The researchers conclude their paper with several public and private sector recommendations.
The rhetoric in Satoshi Nakamoto's "White Paper" on the origins of Bitcoin suggests that the digital currency was envisioned as an entirely autonomous money. Due to the increase in popularity and circulation of Bitcoin and other digital currencies, an intense regulatory debate has been sparked at the global level. These debates reveal a fundamental tension regarding the role of the state in establishing money. While the digital currency community insists that Bitcoin is money, states and monetary authorities have declared Bitcoin a commodity, a declaration that can be traced back to Georg Friedrich Knapp's foundational text The State Theory of Money and reinforced by A. Mitchell Innes' The Credit Theory of Money. Circulating alongside state monies, Bitcoin is then neaccessory money,' unable to satisfy tax obligations and behaving as a commodity. This chartalist account of Bitcoin is refuted by what I identify as a libertarian/von Misean understanding of money motivating the circulation of digital currencies. I argue that the circulation of digital currencies is better explained by the chartalist narrative. I then prescribe Georg Simmel's Philosophy of Money, a broader understanding of money in which more abstract monies might create a supranational economic society, as an ideological alternative to digital currency advocates -- one that better conforms to the nature of money gestured to in Nakamoto's "White Paper". However, even through the lens of Simmel, the limitations imposed by domestic authorities and taxation prevent digital currencies from reaching the envisioned state of autonomy. Synthesizing these understandings of money, Bitcoin may exist as a compromise, a means of international money transfer that weakens the abstract, international economic borders created by state monies.
Pavel Ciaian, Miroslava RajÄĂĄniovĂĄ, dâArtis Kancs
Abstract This paper identifies and analyzes BitCoin features which may facilitate BitCoin to become a global currency, as well as characteristics which may impede the use of BitCoin as a medium of exchange, a unit of account and a store of value, and compares BitCoin with standard currencies with respect to the main functions of money. Among all analyzed BitCoin features, the extreme price volatility stands out most clearly compared to standard currencies. In order to understand the reasons for such extreme price volatility, we attempt to identify drivers of BitCoin price formation and estimate their importance econometrically. We apply time-series analytical mechanisms to daily data for the 2009â2014 period. Our estimation results suggest that BitCoin attractiveness indicators are the strongest drivers of BitCoin price followed by market forces. In contrast, macro-financial developments do not determine BitCoin price in the long-run. Our findings suggest that as long as BitCoin price will be mainly driven by speculative investments, BitCoin will not be able to compete with standard currencies.
This paper explores the financial asset capabilities of bitcoin using GARCH models. The initial model showed several similarities to gold and the dollar indicating hedging capabilities and advantages as a medium of exchange. The asymmetric GARCH showed that bitcoin may be useful in risk management and ideal for risk averse investors in anticipation of negative shocks to the market. Overall bitcoin has a place on the financial markets and in portfolio management as it can be classified as something in between gold and the American dollar on a scale from pure medium of exchange advantages to pure store of value advantages.
This article is aimed at augmenting current awareness of virtual currencies ("VCs") in the South African legal community. To this end, it introduces the reader to VCs in general and decentralised convertible VCs ("DCVCs") in particular. Due to their design and interaction with the real economy and currency, DCVCs are on the radar of many financial regulators worldwide. As Bitcoin is considered the leading type of DCVC in terms of value and volume, its early beginnings in South Africa are probed. Although regulation should follow innovation, awareness of the VC ecosystem will not only warrant appropriate regulatory intervention when the time comes, but will also enable the growth and development opportunities associated with VCs. South Africa has not promulgated any legislation pertaining to VCs. The potential applicability of all current legislation and regulations relevant to VCs calls for in-depth research. This article aspires to serve as an appetiser to do so.
Bitcoin is a decentralized crypto-currency, and an accompanying protocol, created in 2008. Bitcoin nodes continuously generate and propagate blocks---collections of newly approved transactions that are added to Bitcoin's ledger. Block creation requires nodes to invest computational resources, but also carries a reward in the form of bitcoins that are paid to the creator. While the protocol requires nodes to quickly distribute newly created blocks, strong nodes can in fact gain higher payoffs by withholding blocks they create and selectively postponing their publication. The existence of such selfish mining attacks was first reported by Eyal and Sirer, who have demonstrated a specific deviation from the standard protocol (a strategy that we name SM1). In this paper we extend the underlying model for selfish mining attacks, and provide an algorithm to find $Δ$-optimal policies for attackers within the model, as well as tight upper bounds on the revenue of optimal policies. As a consequence, we are able to provide lower bounds on the computational power an attacker needs in order to benefit from selfish mining. We find that the profit threshold -- the minimal fraction of resources required for a profitable attack -- is strictly lower than the one induced by the SM1 scheme. Indeed, the policies given by our algorithm dominate SM1, by better regulating attack-withdrawals. Using our algorithm, we show that Eyal and Sirer's suggested countermeasure to selfish mining is slightly less effective than previously conjectured. Next, we gain insight into selfish mining in the presence of communication delays, and show that, under a model that accounts for delays, the profit threshold vanishes, and even small attackers have incentive to occasionally deviate from the protocol. We conclude with observations regarding the combined power of selfish mining and double spending attacks.
Virtual currencies have been well-cited and well-discussed in the near past. Due to the loss of trust in the banking sector and the fear of loss of capital, low interest rates and uncertainty of existing currencies, the ground for a virtual currency was given. Virtual currencies and the money flows are controlled only online by the anonymous group of volunteers (also called peer); every single transaction is documented. Approximately 10,000 businesses worldwide accept payments with virtual currencies already, and the number is increasing steadily. This article analyzes the advantages and disadvantages of virtual currencies in comparison to real money and gives an outlook to a new banking system with high transparency and the chance to lead to a paradigm shift in the world of transactions and banking.
Bitcoin was not the first attempt at a digital currency, but it has been the most successful and it is now being accepted by a number of major retailers. Bitcoin is a cryptocurrency and operates as a peer-to-peer network. Its security is guaranteed by cryptographic algorithms instead of governments and has the potential to become a major means of payment for e-commerce and may even materialize as a viable challenge to traditional money-transfer providers. Instead of serving one country or some countries, Bitcoin serves the entire world.
The use of Bitcoin as an alternative to traditional âflatâ currency is âunnerving precisely because a world where it is used for all transactions is one where the ability of a central bank to guide the economy is destroyed, by design.â Bitcoin, the first decentralized digital currency, is a peer-to-peer payment system that allows international transactions to take place at any hour and in any place for very low cost. This Note analyzes Bitcoin and ultimately proposes a short-term solution to Bitcoinâs regulatory uncertainty that aims to strike a balance between the governmentâs interest in regulation and Bitcoinâs rejection of central authority â a loosely defined legal framework that operates with a minimal degree of governmental intervention.
The emergence of Bitcoin as a means to make electronic transactions directly across a peer-to-peer network has sparked interest from many fields, mostly due to its capability to handle such transactions on a large scale, with no recourse to centralised structures of management. This is achieved through its underlying technical architecture, the ‘block chain’: an impressively robust system of recording transactions on a network that’s security is guaranteed via the distribution of all transaction data (in blocks) to every node in the system on an ever-increasing chain. Last year saw the emergence of ‘Bitcoin 2.0’ applications, where vast amounts of investment capital flowed into projects that proposed to develop systems that offer a diverse range of applications beyond crypto-currencies, such as voting systems, electronic contracts, financial services, and identification recognition. What unifies these projects is the desire to replace centralised, human-run organisations, with cryptographically secure, automated peer-to-peer systems. Within this desire is a political vision, a vision that is not at all homogenous, nor harmonious, but nonetheless contains central elements that can be traced in the formation of Bitcoin. This paper seeks to explore this vision, drawing on primary research data to examine the technical politics of crypto-currencies. Bitcoin first appeared as a white paper published on The Cryptography Mailing List at metzdowd.com, an open mailing list associated with the internet subculture of cypherpunks – a subculture that fused concerns over increasing state intrusion into everyday life through rapidly growing electronic surveillance, with the open source principles that challenge proprietary software, declare digital technology to be a public good, and thus endeavour to provide alternatives. These values are indeed reflected in Bitcoin’s white paper, and through its public release as an open source project. In the wake of the 2008 financial crisis, and ongoing revelations about coordinated programs of mass state surveillance, many have begun to see Bitcoin as a potentially important public tool. But how exactly, can radical values be embedded in technology? And how does its diffusion among different contexts, and development for different purposes, affect this radical potential? In these respects, I believe it is important to consider the work of Andrew Feenberg. At the crux of Feenberg’s critical theory is the concept of hegemonic technological rationality which, through a dominant form of reasoning, enframes how we understand technology; and through dominant systems of production, entails the exclusion of the interests of marginal social groups. This has the effect of reproducing dominant hegemonic social values through the practices that consequently prosper in this system, practices that structure much of social life and impinge on environments. Feenberg does however, identify two means for subverting this process: democratic intervention on the part of social groups campaigning for alternative technologies; and tactical practices in which marginal groups can reveal alternative potentialities for technology by finding new ways of appropriating the technologies around them. In the collective and voluntary efforts of disparate developers unified by the conviction that digital technologies are and should be a public good – and not proprietary tools of corporate profiteering and state surveillance – we see this latter form of tactical resistance embodied in the origins of Bitcoin. Bitcoin thus opens up alternative possibilities for technological progress, both in ideological and material ways. Materially, Bitcoin opens up further potentialities for tactical practices, as we are seeing with the various ways in which block chain technology is being adapted. Ideologically, Bitcoin introduces its users to systems of thought that challenge dominant understandings of financial technologies and the social structures they support. In this latter sense, Bitcoin has the potential to be a counter-hegemonic force. In this paper however, I will present data that suggests this is not the case, and that in fact Bitcoin is reinforcing the dominant ideals of neoliberalism. In presenting the details of this process, I aim to demonstrate the importance of understanding the development of ‘cultures of knowledge’ that emerge around contemporary technological practices. References and Notes Feenberg, A. (1991) A Critical Theory of Technology . Oxford: University Press Feenberg, A. (1999) Questioning Technology. London: Routledge
Bitcoin has emerged as phenomenon of the financial markets as the currency without any central authority. Recent events of Bitcoin has risen question about its behavior and there is crucial question if the price of Bitcoin follows hypothesis of efficient markets. In this paper, there are introduced the main features of Bitcoin and analyzed its price behavior. We found out that price of the most famous cryptocurrency Bitcoin follows the hypothesis of efficient markets and it immediately react on publicly announce information. Furthermore, Bitcoin can be seen as standard economic good that is priced by interaction of supply and demand on the market. These factors can be driven by macro financial development or by speculative investors, but there werenât found any significant impact of these factors on price of Bitcoin.
We survey recent results on the mathematical stability of Bitcoin protocol. Profitability and probability of a double spend are estimated in closed form with classical special functions. The stability of Bitcoin mining rules is analyzed and several theorems are proved using martingale and combinatorics techniques. In particular, the empirical observation of the stability of the Bitcoin protocol is proved. This survey article on the mathematics of Bitcoin is published by the Newsletter of the European Mathematical Society, vol.115, 2020, p.31-37. Continuation of arXiv:1601.05254 (EMS Newsletter, 100, 2016 p.32).
A peer-to-peer network, enabling different parties to jointly store and run computations on data while keeping the data completely private. Enigma's computational model is based on a highly optimized version of secure multi-party computation, guaranteed by a verifiable secret-sharing scheme. For storage, we use a modified distributed hashtable for holding secret-shared data. An external blockchain is utilized as the controller of the network, manages access control, identities and serves as a tamper-proof log of events. Security deposits and fees incentivize operation, correctness and fairness of the system. Similar to Bitcoin, Enigma removes the need for a trusted third party, enabling autonomous control of personal data. For the first time, users are able to share their data with cryptographic guarantees regarding their privacy.
The availability of data on digital traces is growing to unprecedented sizes, but inferring actionable knowledge from large-scale data is far from being trivial. This is especially important for computational finance, where digital traces of human behavior offer a great potential to drive trading strategies. We contribute to this by providing a consistent approach that integrates various datasources in the design of algorithmic traders. This allows us to derive insights into the principles behind the profitability of our trading strategies. We illustrate our approach through the analysis of Bitcoin, a cryptocurrency known for its large price fluctuations. In our analysis, we include economic signals of volume and price of exchange for USD, adoption of the Bitcoin technology, and transaction volume of Bitcoin. We add social signals related to information search, word of mouth volume, emotional valence, and opinion polarization as expressed in tweets related to Bitcoin for more than 3 years. Our analysis reveals that increases in opinion polarization and exchange volume precede rising Bitcoin prices, and that emotional valence precedes opinion polarization and rising exchange volumes. We apply these insights to design algorithmic trading strategies for Bitcoin, reaching very high profits in less than a year. We verify this high profitability with robust statistical methods that take into account risk and trading costs, confirming the long-standing hypothesis that trading based social media sentiment has the potential to yield positive returns on investment.