Bitcoin is a "crypto currency", a decentralized electronic payment scheme based on cryptography which has recently gained excessive popularity. Scientific research on bitcoin is less abundant. A paper at Financial Cryptography 2012 conference explains that it is a system which "uses no fancy cryptography", and is "by no means perfect". It depends on a well-known cryptographic standard SHA-256. In this paper we revisit the cryptographic process which allows one to make money by producing bitcoins. We reformulate this problem as a Constrained Input Small Output (CISO) hashing problem and reduce the problem to a pure block cipher problem. We estimate the speed of this process and we show that the cost of this process is less than it seems and it depends on a certain cryptographic constant which we estimated to be at most 1.86. These optimizations enable bitcoin miners to save tens of millions of dollars per year in electricity bills. Miners who set up mining operations face many economic incertitudes such as high volatility. In this paper we point out that there are fundamental incertitudes which depend very strongly on the bitcoin specification. The energy efficiency of bitcoin miners have already been improved by a factor of about 10,000, and we claim that further improvements are inevitable. Better technology is bound to be invented, would it be quantum miners. More importantly, the specification is likely to change. A major change have been proposed in May 2013 at Bitcoin conference in San Diego by Dan Kaminsky. However, any sort of change could be flatly rejected by the community which have heavily invested in mining with the current technology. Another question is the reward halving scheme in bitcoin. The current bitcoin specification mandates a strong 4-year cyclic property. We find this property totally unreasonable and harmful and explain why and how it needs to be changed.
Sarah Meiklejohn, Marjori Pomarole, Grant Jordan, Kirill Levchenko · 7 authors
Bitcoin is a purely online virtual currency, unbacked by either physical commodities or sovereign obligation; instead, it relies on a combination of cryptographic protection and a peer-to-peer protocol for witnessing settlements. Consequently, Bitcoin has the unintuitive property that while the ownership of money is implicitly anonymous, its flow is globally visible. In this paper we explore this unique characteristic further, using heuristic clustering to group Bitcoin wallets based on evidence of shared authority, and then using re-identification attacks (i.e., empirical purchasing of goods and services) to classify the operators of those clusters. From this analysis, we characterize longitudinal changes in the Bitcoin market, the stresses these changes are placing on the system, and the challenges for those seeking to use Bitcoin for criminal or fraudulent purposes at scale.
Many want to know what bitcoin is and how it works. But bitcoin is as complex as it is controversial, and relatively few have the technical background to understand it. In this paper, I offer an accessible on-ramp for understanding bitcoin in the form of a model. My model reveals both what bitcoin is and how it works. More specifically, it reveals that bitcoin is a fictional substance in a massively coauthored story on a network that automates and distributes jobs normally entrusted to centralized publishing institutions. My model therefore falsifies a popular view according to which each bitcoin is a chunk of code.
Digital payment schemes show an ever increasing importance. Out of the countless different schemes available this article focuses on the popular Bitcoin system. The authors provide a description of Bitcoin's unique technological basis and its accompanying ecosystem of users, miners, trading platforms and vendors. Furthermore, this article discusses Bitcoin's currency-like features and the first regulatory actions take in the European Union and in the United States of America.
Dániel Kondor, Márton Pósfai, István Csabai, Gábor Vattay
The possibility to analyze everyday monetary transactions is limited by the scarcity of available data, as this kind of information is usually considered highly sensitive. Present econophysics models are usually employed on presumed random networks of interacting agents, and only macroscopic properties (e.g. the resulting wealth distribution) are compared to real-world data. In this paper, we analyze BitCoin, which is a novel digital currency system, where the complete list of transactions is publicly available. Using this dataset, we reconstruct the network of transactions, and extract the time and amount of each payment. We analyze the structure of the transaction network by measuring network characteristics over time, such as the degree distribution, degree correlations and clustering. We find that linear preferential attachment drives the growth of the network. We also study the dynamics taking place on the transaction network, i.e. the flow of money. We measure temporal patterns and the wealth accumulation. Investigating the microscopic statistics of money movement, we find that sublinear preferential attachment governs the evolution of the wealth distribution. We report a scaling relation between the degree and wealth associated to individual nodes.
This paper concerns the open source software project Bitcoin, which is often described as virtual cash. The paper investigates what ‘virtual’ signifies when applied to ‘cash’ and in turn what ‘virtual cash’ says about Bitcoin. Bitcoin is the latest cryptographic effort to create digital cash-like tokens, where Bitcoin’s designer Nakamoto argues that users now no longer have to trust a third party, traditionally the bank. Paradoxically, for Bitcoin it is key that nodes in the network agree on the status of the shared block chain database. Trust remains to be established, albeit in a different manner. Power is not destroyed, but transferred from banks to Bitcoin’s protocol. The paper concludes that ‘virtual’ refers to Bitcoin’s model of how cash appears to function in everyday exchange, allowing user privacy. Bitcoin does not model another aspect of cash, its function as a credential referring to debt. Bitcoin discontinues the concept of debt.
Bitcoin, the cryptocurrency powered by a decentralized peer-to-peer network of computers, has been hot this season. With the exchange rate bobbing around US $100, those involved in creating new bitcoins' and upholding the network that makes them valuable' have become locked in an arms race of sorts, seeking new, powerful machines that will enrich them but that could also destabilize the nascent virtual money.
The Bitcoin network of decentralized payment transactions has attracted a lot of attention from both Internet users and researchers in recent years. Bitcoin utilizes a peer-to-peer network to issue anonymous payment transactions between different users. In the currently used Bitcoin clients, the full transaction history is available at each node of the network to prevent double spending without the need for a central authority, forming a valuable source for empirical research on network structure, network dynamics, and the implied anonymity challenges, as well as guidance on the future evolution of complex payment systems. We found dynamical effects of which some increase anonymity while others decrease it. Most importantly, several parameters of the Bitcoin transaction graph seem to have become stationary over the last 12–18 months. We discuss the implications.
This article examines the use of Bitcoin in money remittance markets as a specific illustration of wider emerging regulatory issues relating to the use of cryptocurrencies. While there are many conceivable benefits of using Bitcoin for remittances, there are also many risks for users of these remittance services. This article adopts a user perspective to look at what the major concerns are and what existing protections may be available to persons using cryptocurrencies under New Zealand law through the example of using Bitcoin for remittance purposes. The article then summarises approaches taken by other jurisdictions before suggesting a specific regulatory approach to cryptocurrencies that New Zealand should consider adopting.
This Comment examines the potentially destabilizing effects of emerging digital currencies on the international foreign currency exchange market. Specifically, it examines "Bitcoin," a decentralized, partially anonymous, and largely unregulated digital currency that has become particularly popular in the last few years. This Comment argues that the International Monetary Fund, the institution responsible for coordinating the stability of foreign exchange rates, is ill-equipped to handle the widespread use of digital currencies in the foreign currency exchange market It highlights the inability of the Fund to intervene in the event of a speculative attack on a currency by Bitcoin users. This Comment concludes by suggesting two interpretations of the Fund's incorporating document, the Articles of Agreement, that would allow it to intervene in the event of such an attack.
This paper investigates the semiotics of Bitcoin, an electronic cash system that uses decentralized networking to enable irreversible payments. For enthusiasts, Bitcoin provides an alternative to currencies and payment systems that are seen to threaten users' privacy, limit personal liberty, and undermine the value of money through state and corporate oversight. Bitcoin's promise lies in its apparent capacity to resolve these concerns not through regulatory institutions or interpersonal trust, but through its cryptographic protocols. We characterize this semiotics as a “practical materialism” and suggest it replays debates about privacy, labor, and value.
A virtual currency can be defined as a type of unregulated, digital money, which is issued and usually controlled by its developers, and used and accepted among the members of a specific virtual community. The recent developments in widely spread internet and data mining activities, highlighted the issue of accepting and using virtual currencies for different purposes, including, buying commodities or services, saving, as well as converting into real currencies, such as US dollars, euro or other currencies. One of the most controversial and the most advanced virtual currency scheme to date is the one so-called Bitcoin, designed and implemented by the Japanese programmer Satoshi Nakamoto in 2009. Although the use of Bitcoin might have positive impact on financial innovation and the provision of additional payment alternatives to consumers, it also might increase the risks in financial payments, exchange rates of real currencies, as well as increase the possibility of money laundering, using them for illegal deeds. Therefore , the purpose of this paper to clarify the main characteristic of Bitcoin, and analyze its positive aspects as well as the threats that may occur to the modern world economy , in case the usage of this money , significantly increases .
In January 2009 the Japanese software-designer SATOSHI NAKAMOTO invented a virtual currency named Bitcoin and released software for managing transactions in the new money.It consists solely of bits and bytes, but we cannot see it as a coin or banknote on the market.There is no cover in terms of gold or stocks, for example -in fact, nothing but the source code of the software which consists of thirty-one thousand lines of code.NAKAMOTO wanted to create a currency immune to potentially predatory bankers and politicians and so the currency and the mechanism to acquire Bitcoin were controlled entirely by software.The payment system is completely decentralised and so contains no central organisation which monitors transactions.Many people use this new currency to pay for services or products on the Internet, since it is no less safe than traditional payment systems.In this paper I will first introduce the basic parameters and functions of the alternative currency, and will deal especially with security and privacy issues relating to the virtual money.After that I will examine the value of Bitcoin on the online market, especially answering questions such as how we can acquire it.After this the legal background will be presented and suggestions made for its possible regulation, whilst its likely role in criminal behaviour is suggested.The paper was written in order to stimulate interest in this special, new currency, its working mechanisms, advantages and possible dangers, and because it represents a unique paradigm-shift, not simply in cyberspace, but in real-world payment systems also.
I employ vector autoregression to identify whether Bitcoin exchange volume shocks increase subsequent real Bitcoin transaction activity outside exchanges. This type of examination is not possible with traditional currency pairs on account of their lack of a perfect ledger mechanism like that of cryptocurrency systems. I find that increased exchange activity has asymmetric effects across user types, with exchange volume innovations tending to stifle the top 100 most popular user wallets than the remaining 2.9 million wallets, many of which are associated with gambling. If you suspect that the exchange activity is for anything other than speculative "hoarding'', the evidence should be found in the transactions between users, and its transmission is very weak. A very persistent response in the exchanges to news innovations was found and is a significant concern from a market manipulation standpoint. Dynamic multipliers were utilized to assess the degree to which money supply increases were distributed across wallet types via transactions. As the money supply increases, I find that the top 100 wallets tend to benefit in the form of increased transactions, while the effect for the millions of remaining wallets remains ambiguous.
This manuscript builds on my existing research program that (a) broadly seeks to analyze laws, regulations, instruments, and policy levers that inhibit a market’s ability to recognize an asset’s intrinsic value, whether in terms of financial, social, or human capital, and (b) explores and advances interdisciplinary corporate governance theories by employing a heterodox economic analytic to derive its proposal to the paradox of an unregulated virtual currency market (Bitcoins) and an overly regulated crowdfunding market (Kickstarter). The manuscript functions not only as an homage to Charles MacKay’s legendary 1841 book, Extraordinary Popular Delusions and the Madness of Crowds, which described the human, social, and economic psychology of financial bubbles — particularly the Dutch tulip bulb bubble — but also as an offering of problems and proposals that crowdfunded and Kickstarted entrepreneurial businesses, including those funded by Bitcoin currencies, present for a wide swath of societal stakeholders. To describe the problem, this manuscript (i) describes behavioral finance, (ii) details the new entrepreneurial business possibilities that virtual currencies and crowdfunded entities can explore, (iii) describes how current rules and regulations represent unnecessary constraints to traditional equity-based funding models and concerning governance models of entrepreneurial enterprises, and (iv) questions why one form of capital deployment (currencies) may provide equity-like returns and unique governance, while the other form of investing (crowdfunding), provides only soft-dollar-like returns and no governance for middle-class investors. While both virtual currencies and crowdfunding represent risks, including economic bubble risk, this Article believes that a heterodox economic analysis demonstrates unnecessary constraints on entrepreneurial businesses imposed by extant regulation, regulators, and law and policymakers. To assuage these paradoxic problems for emerging business enterprises, this Article proposes a minarchist heterodox solution of modest statutory language that requires market-based solutions that employ needed risk reduction strategies while redeploying necessary capital to private startup business enterprises. This proposal thus benefits the middle class entrepreneurs, suppliers of capital, and job seekers harmed by the current regulatory regime, while permitting for an expansion of the U.S. and global economies.
An innovative software technology known as Bitcoin makes it easier for software to operate with some degree of financial autonomy. In a meaningful sense, it is now possible for software to conduct business on its own account, without using the traditional financial system as an intermediary and without a financial existence tied to an existing natural or legal person. This Essay explores this possibility and suggests that legally autonomous entities, such as a limited liability company (LLC) with no members, are a useful legal structure for factually autonomous systems.
This paper will discuss and evaluate the design features of Bitcoin in relation to the libertarian and metallist philosophies that have shaped the cryptocurrency. Bitcoin has failed to be perfectly decentralized or particularly anonymous. Furthermore, its hyperdeflationary design features have made Bitcoin a currency dependent on outside, more stable currencies (e.g., the U.S. dollar), which serve as units of account. Finally, despite the view of money taken by its creators, this supposedly stateless currency is far from apolitical in nature. Although its creators tend to espouse apolitical accounts of money, Bitcoin has been from the beginning a political project -- an evolving, distributed constitutional project, with many goals, visions, and factions. Furthermore, depending on the shape of these political goals, Bitcoin advocates may or may not have a vested interest in creating mechanisms to stabilize the currency and make it a viable unit of account. This paper was written for Christine Desan's seminar, "The Constitutional Law of Money," at Harvard Law School.
Virtual currencies are online payment systems that may function as real currencies but are not issued or backed by central governments. As demonstrated by recent events, virtual currencies present regulators with significant challenges. On May 23, 2013, the U.S. federal government brought an indictment against the operators of Liberty Reserve, a popular virtual currency, charging the operators with money laundering and operating an unlicensed money-transmitting business. The same month, the Government Accountability Office ("GAO") made public a report exploring the potential tax-compliance risks associated with virtual currencies and economies. Legislators have also taken particular interest in one type of virtual currency-Bitcoin. On August 13, 2013, the U.S. Senate Committee on Homeland Security announced plans to start an inquiry aimed at establishing a regulatory framework for Bitcoin. This short Essay describes the mechanisms by which "cryptocurrencies"-a subcategory of virtual currencies-could replace tax havens as the weapon-of-choice for tax-evaders. I argue that it is reasonable to expect this shift to occur in the foreseeable future due to the contemporary convergence of two unrelated, yet parallel, processes. The first process is the increasing popularity of cryptocurrencies, of which Bitcoin is the most widely recognized example. Unlike other virtual currencies that are associated with the existence of a virtual economy-usually in computer games-cryptocurrencies "function as a unique currency with [their] own free-floating exchange." Over the past three years, Bitcoin gradually gained the confidence of consumers, retailers, and service providers, and it is now effectively functioning as a currency in the real world. In fact, in August 2013, Bitcoin was officially recognized as a legal form of tender in Germany. Only two weeks earlier, a federal judge ruled that for purposes of U.S. securities regulation, Bitcoin is indeed "money."
Cryptocurrencies are digital alternatives to traditional government‐issued paper monies. Given the current state of technology and skepticism regarding the future purchasing power of existing monies, why have cryptocurrencies failed to gain widespread acceptance? I offer an explanation based on network effects and switching costs. In order to articulate the problem that agents considering cryptocurrencies face, I employ a simple model developed by Dowd and Greenaway (1993) (Dowd, K., and D. Greenaway. “Currency Competition, Network Externalities, and Switching Costs: Towards an Alternative View of Optimum Currency Areas.” The Economic Journal , 103(420), 1993, 1180–89). The model demonstrates that agents may fail to adopt an alternative currency when network effects and switching costs are present, even if all agents agree that the prevailing currency is inferior. The limited success of bitcoin—almost certainly the most popular cryptocurrency to date—serves to illustrate. After briefly surveying episodes of successful monetary transition, I conclude that cryptocurrencies like bitcoin are unlikely to generate widespread acceptance in the absence of either significant monetary instability or government support. ( JEL E40, E41, E42, E49)