Blockchain Papers

Follow blockchain research across journals, conferences, and preprint repositories.

12,736 papersLast indexed Aug 16, 2026
Search papers

Paper index

12,736 results ¡ page 529 of 531

Clear filters
Jan 1, 2014·˜The œindependent review
81 cites
Cryptocurrency and the Problem of Intermediation

Cameron Harwick

Though Bitcoin currently enjoys a healthy niche, the aspirations of many in the project are grander: to supplant the existing regime of fiat currencies with cryptocurrencies, and to do so outside of normal political channels. Its primary practical obstacle is its purchasing power volatility, arising from a rigid money stock in the face of wide swings in demand. Nevertheless, the historical example of gold, another (much more successful) money commodity with a more or less rigid supply, illuminates the institutional prerequisites for purchasing power stability, economic efficiency, and sustained growth – namely a market of financial intermediaries whose liabilities denominated in the base money themselves circulate as media of exchange. This paper discusses potential benefits and hurdles to establishing financial intermediation in cryptocurrency, as well as the possibility of managing the money supply to create a stable purchasing power cryptocurrency without the need for intermediation at all. Such schemes ultimately require an existing market of intermediaries in order to provide any benefits, the emergence of which governments are for the moment well-positioned to prevent.

Open access
3 source records
Blockchain Technology Applications and Security
Global Financial Crisis and Policies
Banking stability, regulation, efficiency
Original source
Jan 1, 2014¡SSRN Electronic Journal
116 cites
Competition in the Cryptocurrency Market

Hanna Hałaburda, Neil Gandal

We analyze how network effects affect competition in the nascent cryptocurrency market. We do so by examining the changes over time in exchange rate data among cryptocurrencies. Specifically, we look at two aspects: (1) competition among different currencies, and (2) competition among exchanges where those currencies are traded. Our data suggest that the winner-take-all effect is dominant early in the market. During this period, when Bitcoin becomes more valuable against the U.S. dollar, it also becomes more valuable against other cryptocurrencies. This trend is reversed in the later period. The data in the later period are consistent with the use of cryptocurrencies as financial assets (popularized by Bitcoin), and not consistent with "winner-take-all" dynamics.

Open access
4 source records
Blockchain Technology Applications and Security
Digital Platforms and Economics
Game Theory and Applications
Original source
Jan 1, 2014¡Cato Journal
107 cites
The Market for Cryptocurrencies

Lawrence H. White

Cryptocurrencies like Biteoin are transferable digital assets, secured by cryptography. To date, all of them have been created by private individuals, organizations, or firms. Unlike bank account balances, they are not anyone's liability. They are not redeemable for any government fiat money such as Federal Reserve Notes or for any commodity money such as silver or gold coins. The cryptocurrency is thus a of competing private irredeemable monies (or would-be monies). Friedrich A. Hayek (1978a) and other economists over the last 40 years could only imagine how competition among issuers of private irredeemable monies would work. Today we have an actual study. In what follows I will discuss the main economic features of the market. I also discuss whether the is purely a bubble. As an introduction the topic, I offer the following comic verse about the contrast between Biteoin and the physical gold coins of the past: In the past, money's value was judged with our teeth; We bit coins confirm they were real. Now a Bitcoin's just data, no gold underneath. That's okay if it buys you a meal. (1) The Size and Composition of the Cryptocurrency Market Bitcoin rightly gets the lion's share of media attention, but it is not alone in the for cryptocurrencies. The authoritative website CoinMarketCap.com tracks the U.S. dollar price and total market (price per unit multiplied by number of units outstanding) for each of more than 500 traded cryptocurrencies. Bitcoin is the largest by far. On a recent day (March 9, 2015), the site showed Bitcoin trading at $291 per unit, with a cap of $4.05 billion. The second and third largest cryptocurrencies, Ripple and Litecoin, had caps respectively 8.5 percent and 1.8 percent as large. The entire set of non-Bitcoin cryptocurrencies (known as altcoins) had a cap of roughly $619 million, or 15 percent of Bitcoin's. Stated differently, Bitcoin had roughly 87 percent of the market, altcoins 13 percent. In percentage terms, altcoins do a higher share of Bitcoin's business than Bitcoin does of the Federal Reserve Note's business (currently $1.35 trillion in circulation). In trading volume the percentage share of altcoins (led by litecoin and Ripple) has been similar. The cryptocurrency has grown about fourfold in cap over the last 22 months, with altcoins growing faster than Bitcoin. This is seen by comparing recent data the oldest snapshot of the CoinMarketCap site available via the Internet Archive Wayback Machine, which reports data for May 9, 2013. On that date, Bitcoin had a price of $112 per unit, and a cap of $1.2 billion. The two largest altcoins at that time, Litecoin and Peercoin (aka PPCoin), had caps respectively 4.7 percent and 0.4 percent as large. Only 13 altcoins were listed. Jointly their cap was about 6 percent of Bitcoin's, giving Bitcoin 95 percent of the market. Since then, the share of altcoins has doubled, and their cap has grown ninefold. Trading volumes then were not reported. At $4.05 billion, the cap of Bitcoin, as of March 2015, was slightly smaller than the dollar value of the September 2014 monetary bases of the Lithuanian litas ($5.8 billion) and the Guatemalan quetzal ($5.5 billion), but larger than those of the Costa Rican colon ($3.3 billion) and the Serbia dinar ($3.3 billion). (2) The August 2014 figures from the Central Bank of the Bahamas do not provide the monetary base, but count Bahamian dollar currency in circulation at $210 million, less than two-thirds of Ripple's recent cap of around $344 million. Medium of Exchange, Store of Value, and Medium of Remittance Functions The retail use of Bitcoin as a medium of exchange for goods and services is small date, but is growing. In December 2014, Microsoft began accepting bitcoin payments to buy content such as games and videos on Xbox game consoles, add apps and services Windows phones or buy Microsoft software (BBC 2014). …

Open access
2 source records
Blockchain Technology Applications and Security
Digital Platforms and Economics
Economic theories and models
Original source
Jan 1, 2014¡SSRN Electronic Journal
57 cites
The Economics of Bitcoin Transaction Fees

Nicolas Houy

We study the economics of Bitcoin transaction fees in a simple static partial equilibrium model with the specificity that the system security is directly linked to the total computational power of miners. We show that any situation with a fixed fee is equivalent to another situation with a limited block size. In both cases, we give the optimal value of the transaction fee or of the block size. We also show that making the block size a non binding constraint and, in the same time, letting the fee be fixed as the outcome of a decentralized competitive market cannot guarantee the very existence of Bitcoin in the long-term.

Open access
2 source records
Blockchain Technology Applications and Security
Economic theories and models
Auction Theory and Applications
Original source
Jan 1, 2014¡SSRN Electronic Journal
69 cites
Bitcoin: Technical Background and Data Analysis

Anton Badev, Matthew Chen

This paper provides the necessary technical background to understand basic Bitcoin operations and documents a set of empirical regularities related to Bitcoin usage. We present the micro-structure of the Bitcoin transaction process and highlight the use of cryptography for the purposes of transaction security and distributed maintenance of a ledger. Using publicly available transaction-level data, we examine patterns of general usage together with usage by Satoshi Dice, the largest online gambling service using Bitcoin as the method of payment. Our analysis suggests that less than 50 percent of all bitcoins in circulation are used in transactions. About half of these transactions involve less than U.S.$100 equivalent, and for the period for which we have data for Satoshi Dice, most of these small-value transactions were related to the online gambling service. Relatively less frequent large value transactions drive the average transaction value to levels above U.S.$40,00 0 equivalent value, and are not likely to involve payments for goods and services. Bitcoin exchange rates exhibit somewhat complicated dynamics. In the past 24 months, the USD-BTC exchange rate increased more than 50-fold. The daily variance of the USD-BTC exchange rate remained remarkably stable for this same period, once the variance calculations account for the changing exchange rate level. We also document that the exchange rates between bitcoin and other major currencies are not well aligned. We interpret this as lack of depth of the exchange markets and as costly exchange rather than as unexploited arbitrage opportunities. Finally, we examine the economic incentives for the participants in the distributed implementation of the Bitcoin scheme.

Open access
4 source records
Blockchain Technology Applications and Security
Caching and Content Delivery
Spam and Phishing Detection
Original source
Jan 1, 2014·New York Law School’s Digital Commons (New York Law School)
54 cites
Bitcoin Financial Regulation

Jerry Brito, Houman B. Shadab, Andrea Castillo

The next major wave of Bitcoin regulation will likely be aimed at financial instruments, including securities and derivatives, as well as prediction markets and even gambling. While there are many easily regulated intermediaries when it comes to traditional securities and derivatives, emerging bitcoin-denominated instruments rely much less on traditional intermediaries such as banks and securities exchanges. Additionally, the block chain technology that Bitcoin introduced for the first time makes completely decentralized markets and exchanges possible, thus eliminating the need for intermediaries in complex financial transactions. In this Article we survey the type of financial instruments and transactions that will most likely be of interest to regulators, including traditional securities and derivatives, new bitcoin-denominated instruments, and completely decentralized markets and exchanges. We find that Bitcoin derivatives would likely not be subject to the full scope of regulation under the Commodity Exchange Act to the extent that such derivatives involve physical delivery (as opposed to cash settlement) or are non-fungible and not independently traded. We also find that some laws, including those aimed at online gambling, do not contemplate a payment method like Bitcoin, thus placing many transactions in a legal gray area. Following the approach to virtual currencies taken by the Financial Crimes Enforcement Network, we argue that other financial regulators should consider exempting or excluding certain financial transactions denominated in Bitcoin from the full scope of their regulations, much like private securities offerings and forward contracts are treated. We also suggest that to the extent that regulation and enforcement becomes more costly than its benefits, policymakers should consider and pursue strategies consistent with that new reality, such as efforts to encourage resilience and adaptation by existing institutions.

Open access
2 source records
Banking stability, regulation, efficiency
Blockchain Technology Applications and Security
FinTech, Crowdfunding, Digital Finance
Original source
Jan 1, 2014¡SSRN Electronic Journal
75 cites
Can Bitcoin Become a Major Currency?

William J. Luther, Lawrence H. White

At present, bitcoin is held mostly as a speculative vehicle, little used to pay for goods and services. Its value has been unstable, which impedes bitcoin’s wider use as a payment medium. We explain why the value of bitcoin has been so unstable. Then, we discuss entrepreneurial efforts that might enable bitcoin to become a more commonly accepted payment medium.

Open access
2 source records
Economic theories and models
Economic Theory and Policy
Monetary Policy and Economic Impact
Original source
Jan 1, 2014¡RePEc: Research Papers in Economics
100 cites
The issue of competing currencies. Case study – Bitcoin

Angela Rogojanu, Liana Badea

The complexity and interdependence of the economies of various geographical and political entities have one generic binder - money. The economic history of the last century, replicated in the first decade of our century, can be “written” with money. Indeed, money, a multiple discovery of the civilization in its historical way, was and still is the guardian of hope for prosperity. The disputes about money clearly indicate the need, opportunity and the possibility of monetary competition, which would provide, from the point of view of entrepreneurs, the most suitable production of money based on expectations of their economic preferences. Increasingly more, theorists, practitioners and analysts bring to the fore the issue of simultaneously using the official currency and the digital one. Thus, the issue of the public debate regarding the private money is still of interest. Based on these considerations, this paper aims to highlight how the digital currency Bitcoin can meet the challenges of the economic environment, taking into account both the opportunities and the threats to which it is subject, and the records emphasized by the history of economic thought and adapted to the current reality.

Open access
Blockchain Technology Applications and Security
Market Dynamics and Volatility
Economic theories and models
Original source
Jan 1, 2014¡SSRN Electronic Journal
65 cites
Bitcoin Myths and Facts

Campbell R. Harvey

I will address eight common claims about bitcoin: 1. Physical bitcoins exist; 2. The founder of bitcoin is a person called Satoshi Nakamoto; 3. Bitcoin is mainly used for criminal activity; 4. A lack of security plagues bitcoin; 5. Mining is a waste of energy; 6. Bitcoin too small today to be an important economic force; 7. Bitcoin is currently too volatile to be viable; 8. Bitcoin is just another currency. For additional details beyond "Bitcoin Myths and Facts," I have another paper/slidedeck called "Cryptofinance" that goes deeper into the mechanics of cryptocurrencies. It is available at http://ssrn.com/abstract=2438299 .

Open access
2 source records
Crime, Illicit Activities, and Governance
Economic theories and models
Blockchain Technology Applications and Security
Original source
Jan 1, 2014
79 cites
Exploring the Bitcoin Network

Annika Baumann, Benjamin Fabian, Matthias Lischke

Bitcoin is a peer-to-peer (P2P) payment network running on a cryptographic protocol. Nodes of Bitcoin communicate to each other by broadcasting digitally signed messages to the network. Transactions are listed in a distributed, decentralized, public database referred to as the block, using a proof of work to reach consensus. The term “Bitcoin network” refers to a set of nodes running the P2P protocol. The structure of the Bitcoin network is minimal with a decentralized network of volunteers. This chapter presents the overall process of Bitcoin networks including transactions, digital signatures, relay networks, and Bitcoin script.

Open access
2 source records
Blockchain Technology Applications and Security
Original source
Jan 1, 2014¡SSRN Electronic Journal
55 cites
The Bitcoin Mining Game

Nicolas Houy

No abstract is available for this record.

Open access
Blockchain Technology Applications and Security
Crime, Illicit Activities, and Governance
Original source
Jan 1, 2014¡Applied Economics Letters
239 cites
Characteristics of Bitcoin users: an analysis of Google search data

Aaron Yelowitz, Matthew W. Wilson

The anonymity of Bitcoin prevents analysis of its users. We collect Google Trends data to examine determinants of interest in Bitcoin. Based on anecdotal evidence regarding Bitcoin users, we construct proxies for four possible clientele: computer programming enthusiasts, speculative investors, Libertarians and criminals. Computer programming and illegal activity search terms are positively correlated with Bitcoin interest, while Libertarian and investment terms are not.

Open access
3 source records
Crime, Illicit Activities, and Governance
Data-Driven Disease Surveillance
Cybercrime and Law Enforcement Studies
Original source
Jan 1, 2014¡Economic Inquiry
160 cites
THE POLITICAL ECONOMY OF BITCOIN

Joshua R. Hendrickson, Thomas L. Hogan, William J. Luther

The recent proliferation of bitcoin has been a boon for users but might pose problems for governments. Indeed, some governments have already taken steps to ban or discourage the use of bitcoin. In a model with endogenous matching and random consumption preferences, we find multiple monetary equilibria including one in which bitcoin coexists with official currency. We then identify the conditions under which government transactions policy might deter the use of bitcoin. We show that such a policy becomes more difficult if some users strictly prefer bitcoin because they can avoid other users holding the official currency in the matching process. ( JEL C78, E41, E42, E50)

Open access
2 source records
Economic theories and models
Consumer Market Behavior and Pricing
Blockchain Technology Applications and Security
Original source
Jan 1, 2014¡SSRN Electronic Journal
365 cites
Price Fluctuations and the Use of Bitcoin: An Empirical Inquiry

Michał Polasik, Anna Piotrowska, Tomasz Piotr Wisniewski, Radosław Kotkowski · 5 authors

Over recent years, interest has been growing in Bitcoin, an innovation that has the potential to play an important role in e-commerce and beyond. The aim of our paper is to provide a comprehensive empirical study of the payment and investment features of Bitcoin, and their implications for the conduct of e-commerce. Since network externality theory suggests that the value of a network and its take-up are interlinked, we investigate both adoption and price formation. We discover that its returns are driven primarily by Bitcoin’s popularity, the sentiment expressed in newspaper reports on cryptocurrency, and total number of transactions. The paper also reports on the first global survey of merchants who have adopted this technology, and we model the share of sales paid for with this alternative currency, using both ordinary and Tobit regressions. Our analysis examines how country-, customer-, and company-specific characteristics interact with the proportion of sales attributed to Bitcoin. We find that company features, use of other payment methods, customers’ knowledge about Bitcoin, and the size of both the official and unofficial economy are significant determinants. The results will be of interest to traders who seek to understand factors driving prices and will help to inform vendors as to the most favorable circumstances for adopting the currency for online transactions.

Open access
2 source records
Blockchain Technology Applications and Security
Digital Platforms and Economics
Auction Theory and Applications
Original source
Jan 1, 2014¡Publication Server of Goethe University Frankfurt am Main (Goethe University Frankfurt)
460 cites
BITCOIN - ASSET OR CURRENCY? REVEALING USERS' HIDDEN INTENTIONS

Florian Glaser, Kai Zimmermann, Martin Haferkorn, Moritz Weber ¡ 5 authors

Digital currencies are a globally spreading phenomenon that is frequntly and also prominently addressed by media, venture capitalists, financial and governmental institutions alike. As exchange prices for Bitcoin have reached multiple peaks within 2013, we pose a prevailing and yet academically unaddressed qustion: What are users' intentions when changing their domestic into a digital currency? In particular, this paper aims at giving empirical insights on whether users´ interest regarding digital currencies is driven by its appeal as an asset or as a currency. Based on our evaluation, we find strong indications that especially uninformed users approaching digital currencies are not primarily interested in an alternative transaction system but seek to participate in an alternative investment vehicle.

Open access
Blockchain Technology Applications and Security
Economic theories and models
Complex Systems and Time Series Analysis
Original source
Jan 1, 2014¡IACR Cryptology ePrint Archive
1,905 cites
Zerocash: Decentralized Anonymous Payments from Bitcoin.

Eli Ben‐Sasson, Alessandro Chiesa, Christina Garman, Matthew Green · 7 authors

Bit coin is the first digital currency to see widespread adoption. While payments are conducted between pseudonyms, Bit coin cannot offer strong privacy guarantees: payment transactions are recorded in a public decentralized ledger, from which much information can be deduced. Zero coin (Miers et al., IEEE S&P 2013) tackles some of these privacy issues by unlinking transactions from the payment's origin. Yet, it still reveals payments' destinations and amounts, and is limited in functionality. In this paper, we construct a full-fledged ledger-based digital currency with strong privacy guarantees. Our results leverage recent advances in zero-knowledge Succinct Non-interactive Arguments of Knowledge (zk-SNARKs). First, we formulate and construct decentralized anonymous payment schemes (DAP schemes). A DAP scheme enables users to directly pay each other privately: the corresponding transaction hides the payment's origin, destination, and transferred amount. We provide formal definitions and proofs of the construction's security. Second, we build Zero cash, a practical instantiation of our DAP scheme construction. In Zero cash, transactions are less than 1 kB and take under 6 ms to verify - orders of magnitude more efficient than the less-anonymous Zero coin and competitive with plain Bit coin.

Open access
2 source records
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Cryptography and Data Security
Original source
Dec 25, 2013¡arXiv (Cornell University)
75 cites
Cryptocurrency Mining Games with Economic Discount and Decreasing Rewards

Marcelo Arenas, Juan L. Reutter, Etienne Toussaint, Martín Ugarte ¡ 6 authors

In the consensus protocols used in most cryptocurrencies, participants called miners must find valid blocks of transactions and append them to a shared tree-like data structure. Ideally, the rules of the protocol should ensure that miners maximize their gains if they follow a default strategy, which consists on appending blocks only to the longest branch of the tree, called the blockchain. Our goal is to understand under which circumstances are miners encouraged to follow the default strategy. Unfortunately, most of the existing models work with simplified payoff functions, without considering the possibility that rewards decrease over time because of the game rules (like in Bitcoin), nor integrating the fact that a miner naturally prefers to be paid earlier than later (the economic concept of discount). In order to integrate these factors, we consider a more general model where issues such as economic discount and decreasing rewards can be set as parameters of an infinite stochastic game. In this model, we study the limit situation in which a miner does not receive a full reward for a block if it stops being in the blockchain. We show that if rewards are not decreasing, then miners do not have incentives to create new branches, no matter how high their computational power is. On the other hand, when working with decreasing rewards similar to those in Bitcoin, we show that miners have an incentive to create such branches. Nevertheless, this incentive only occurs when a miner controls a proportion of the computational power which is close to half of the computational power of the entire network.

Open access
2 source records
Blockchain Technology Applications and Security
Cryptography and Data Security
Security and Verification in Computing
Original source
Dec 11, 2013¡arXiv (Cornell University)
22 cites
How to deal with malleability of BitCoin transactions

Marcin Andrychowicz, Stefan Dziembowski, Daniel Malinowski, Łukasz Mazurek

BitCoin transactions are malleable in a sense that given a transaction an adversary can easily construct an equivalent transaction which has a different hash. This can pose a serious problem in some BitCoin distributed contracts in which changing a transaction's hash may result in the protocol disruption and a financial loss. The problem mostly concerns protocols, which use a "refund" transaction to withdraw a deposit in a case of the protocol interruption. In this short note, we show a general technique for creating malleability-resilient "refund" transactions, which does not require any modification of the BitCoin protocol. Applying our technique to our previous paper "Fair Two-Party Computations via the BitCoin Deposits" (Cryptology ePrint Archive, 2013) allows to achieve fairness in any Two-Party Computation using the BitCoin protocol in its current version.

Open access
2 source records
cs.CR
Cryptography and Data Security
Blockchain Technology Applications and Security
Original source
Dec 5, 2013¡ORCA Online Research @Cardiff (Cardiff University)
0 cites
Bitcoin—Libertarian dream or environmental hazard?

Richard Maxwell, Toby Miller

Bitcoin is the latest fantasy object of utopian thinkers far and wide. Angry with the banks? It sidesteps them. Fed up with governments? They can’t regulate it. Annoyed by corporations? Bitcoin transcends them. Worried about fraud? Bitcoin uses the latest cryptography. Keen to make a buck (so to speak) by participating in a boom? Come on down and plug in.

Open access
Blockchain Technology Applications and Security
Original source
Dec 4, 2013¡Scientific Reports
858 cites
BitCoin meets Google Trends and Wikipedia: Quantifying the relationship between phenomena of the Internet era

Ladislav KriĹĄtoufek

Digital currencies have emerged as a new fascinating phenomenon in the financial markets. Recent events on the most popular of the digital currencies--BitCoin--have risen crucial questions about behavior of its exchange rates and they offer a field to study dynamics of the market which consists practically only of speculative traders with no fundamentalists as there is no fundamental value to the currency. In the paper, we connect two phenomena of the latest years--digital currencies, namely BitCoin, and search queries on Google Trends and Wikipedia--and study their relationship. We show that not only are the search queries and the prices connected but there also exists a pronounced asymmetry between the effect of an increased interest in the currency while being above or below its trend value.

Open access
2 source records
Media Influence and Politics
Consumer Market Behavior and Pricing
Spam and Phishing Detection
Original source
Dec 3, 2013
1 cites
Botnets and Crypto Currency - Effects of Botnets on the Bitcoin Ecosystem

Hitesh Dharmdasani

Nearly every aspect of a hacked computer and a users online life can be and has been commoditized. Recent trends into crypto currencies have made the former even more true as cyber criminals are now committing crime for monetary benefit and not just to out smart each other. In this study, I look more closely at Bitcoin, a de-centralized crypto currency which has become increasingly popular in the last six months. This study focuses on the analysis of the bitcoin economy, the involvement of malware and botnets and its effect to the currency.

Open access
Blockchain Technology Applications and Security
Original source
Nov 13, 2013¡SSRN Electronic Journal
26 cites
Trust, Identity, and Disclosure: Are Bitcoin Exchanges the Next Virtual Havens for Money Laundering and Tax Evasion?

Sarah Michelle Gruber

This Note discusses the relationship of Bitcoins, a cyber-currency, to the Bank Secrecy Act and discusses money laundering and tax evasion. This Note highlights the use and potentially problematic implications of Bitcoins in commerce and discusses their current regulation by the government, both within the United States and internationally, to guard against these threats. This Note addresses the regulation of Bitcoin exchanges, the exchanges' vulnerability to cyber-attacks, and the value of trust to the users of Bitcoin exchanges. This Note concludes that well known exchanges that operate both within and outside the United States generally self-regulate in order to gain the trust of their users despite the cyber-attacks on exchanges in the past. This Note also addresses the tax-reporting implications of foreign Bitcoin exchanges, looking by analogy at attempts to gain information from known tax havens.This Note argues that, given the applicability of the BSA to Bitcoin exchanges, the Bitcoin system poses serious questions relating to money laundering and tax reporting, mostly with regard to the less trustworthy exchanges known for their illegal activity. Some Bitcoin exchanges and e-wallets may also have the potential to become the next tax havens. Many exchanges voluntarily implement measures amounting to self-regulation in attempts to appear more trustworthy to wary consumers or in attempts to avoid criminal or civil sanctions. Whether this self-regulation is sufficient to achieve the goals of preventing money laundering and other criminal activity is debatable. Exchanges that have no need to appear trustworthy, however, still pose the same risks of money laundering and other illegal activity contemplated by the FBI. Moreover, ways exist in which criminals can work around the current regulatory scheme to achieve criminal goals; in that respect, the current regulatory scheme is ineffective to prevent the targeted criminal activity. This Note recommends a supplemental regulatory scheme that would target the areas that current regulation fails to address in combating money laundering, tax evasion, and other criminal activity.

Open access
Crime, Illicit Activities, and Governance
Blockchain Technology Applications and Security
FinTech, Crowdfunding, Digital Finance
Original source
Nov 1, 2013¡arXiv (Cornell University)
1,402 cites
Majority is not Enough: Bitcoin Mining is Vulnerable

Ittay Eyal, Emin GĂźn Sirer

The Bitcoin cryptocurrency records its transactions in a public log called the blockchain. Its security rests critically on the distributed protocol that maintains the blockchain, run by participants called miners. Conventional wisdom asserts that the protocol is incentive-compatible and secure against colluding minority groups, i.e., it incentivizes miners to follow the protocol as prescribed. We show that the Bitcoin protocol is not incentive-compatible. We present an attack with which colluding miners obtain a revenue larger than their fair share. This attack can have significant consequences for Bitcoin: Rational miners will prefer to join the selfish miners, and the colluding group will increase in size until it becomes a majority. At this point, the Bitcoin system ceases to be a decentralized currency. Selfish mining is feasible for any group size of colluding miners. We propose a practical modification to the Bitcoin protocol that protects against selfish mining pools that command less than 1/4 of the resources. This threshold is lower than the wrongly assumed 1/2 bound, but better than the current reality where a group of any size can compromise the system.

Open access
3 source records
Blockchain Technology Applications and Security
Cryptography and Data Security
Internet Traffic Analysis and Secure E-voting
Original source