This thesis illustrates forensic research work on Bitcoin, an innovative Internet based global transaction system that attracts ascending popularity during the recent few years. As an open, public and scalable distributed payment system, Bitcoin brings forward significant economic and technological impact to our world. Meanwhile, a new notion of virtual currency, "Bitcoin" comes into existence such that Bitcoin currency can be "mined" from all over world complying with specific algorithms. Mined bit "coins" has practical monetary values that turn the Bitcoin system into a digital currency circulation system. Due to Bitcoin's decentralized semantics, Bitcoin transaction and currency are not subject to control and censorship from any single authority. Therefore, Bitcoin brings out various security concerns about its application as a long-term reliable system.\nThe research in the thesis focuses on forensic study on Bitcoin. It covers experimental study on the Bitcoin network as a peer-to-peer system and a graph-based forensic approach against Bitcoin's transaction data. Major contributions include network data evaluation and transaction history analysis. In case of forensic investigation is needed against criminal incidents such as fraud, false transactions and money theft, which are commonly seen in commonly used digital payment systems, the research provides a guidance of efficient information collection and framework of evidence data processing and extraction
The present study addresses one of the most problematic phenomena: Bitcoin price. We explore the Granger causality for two relationships (Bitcoin price and transactions; Bitcoin price and investorsâ attractiveness) from a frequency domain perspective using Breitung and Candelonâs (2006) approach. Intuitively, this research gauges empirically the causal links between these variables unconditionally on the one hand and conditionally to the Chinese stock market and the processing power of Bitcoin network on the other hand. The observed outcomes reveal some differences with respect to the frequencies involved, highlighting the complexity of assessing what Bitcoin looks like and the difficulty to gain clearer insights into this nascent crypto-currency. Beyond the nuances of short-, medium- and long-run frequencies, this paper confirms the extremely speculative nature of Bitcoin without neglecting its usefulness in economic reasons (trade transactions). The consideration of the Chinese market index and the hash rate has led to solid and unambiguous findings connecting further Bitcoin to speculation.
Abstract. We construct a 3-move public coin special honest verifier zero-knowledge proof, a so-called Sigma-protocol, for a list of commitments having at least one commit-ment that opens to 0. It is not required for the prover to know openings of the other commitments. The proof system is efficient, in particular in terms of communication requiring only the transmission of a logarithmic number of commitments. We use our proof system to instantiate both ring signatures and zerocoin, a novel mech-anism for bitcoin privacy. We use our Sigma-protocol as a (linkable) ad-hoc group identi-fication scheme where the users have public keys that are commitments and demonstrate knowledge of an opening for one of the commitments to unlinkably identify themselves (once) as belonging to the group. Applying the Fiat-Shamir transform on the group identification scheme gives rise to ring signatures, applying it to the linkable group iden-tification scheme gives rise to zerocoin. Our ring signatures are very small compared to other ring signature schemes and we only assume the users â secret keys to be the discrete logarithms of single group elements so the setup is quite realistic. Similarly, compared with the original zerocoin protocol we rely on a weak cryptographic assumption and do not require a trusted setup. A third application of our Sigma protocol is an efficient proof of membership of a secret committed value u belonging to a public list L = {λ1,..., λN}.
This working paper presents a simple model for the macroeconomic behavior of bitcoin based on the economic equation of exchange. According to this model, the value of bitcoin is determined largely by the willingness of bitcoin holders to save bitcoin and not by its transactional use. This model therefore predicts that increased use of bitcoin will not cause its value to rise, but that the value of bitcoin in terms of fiat currency will be almost solely determined by the willingness of bitcoin holders to pull bitcoin out of circulation. This model suggests that bitcoin will not fall victim to a liquidity trap as suggested by some economists.
When processing transactions in a block, a miner increases his reward but also decreases his probability to earn any reward because the time needed for his block to reach consensus depends on its size. We show that this leads to a game situation between miners. We analytically solve this game for two miners. Then, we show that miners do not play a Nash equilibrium in the current Bitcoin mining environment, instead, they should not process any transaction. Finally, we show that the situation where no transaction is ever processed would stop being a Nash equilibrium if the transaction fee was multiplied or, equivalently, the fixed reward divided by a factor of about 12.
The proliferation of technology emphasized new forms of payment. During the last years, current literature highlighted the role of virtual currency, the channels of payment through digital coins and the importance of assimilation of such platforms. Bitcoin or BTC is known as a digital coin, issued for the first time in 2009 and based on a peer to peer system. The difference from other forms of payment is that BTC is not controlled by any institution or central authority. BTC transactions have grown rapidly, âasking" for regulation measures or legal approval of governments. Although BTC has become very popular, the market is poor and unfortunately of no confidence. There is a lack of regulation which can determine a number of risks associated with criminal financing activities. However, the legal status of Bitcoin is present in many European countries like Belgium, Bulgaria, Denmark, Finland, Germany, Lithuania, Norway, Poland, Slovenia, Switzerland or Turkey. Also, this type of currency has experienced a rapid evolution among coffee shops and restaurants.
Robleh Ali, John Barrdear, Roger Clews, James Southgate
Modern electronic payment systems rely on trusted, central third parties to process payments securely. Recent developments have seen the creation of digital currencies like Bitcoin, which combine new currencies with decentralised payment systems. Although the monetary aspects of digital currencies have attracted considerable attention, the distributed ledger underlying their payment systems is a significant innovation. As with money held as bank deposits, most financial assets today exist as purely digital records. This opens up the possibility for distributed ledgers to transform the financial system more generally.
A private initiative that has created a virtual currency and a payment system based on cryptography and decentralized management, Bitcoin is considered not only an interesting, but also a disruptive technical innovation by many observers. A number of regulatory and supervisory bodies have issued assessments of the phenomenon, contributing to an emerging international discussion. Does Bitcoinâs claim to provide useful monetary and payment services hold up when checked against principles of monetary theory and the economics of payment systems? We find that while Bitcoin does not rival the established money and payment systems in their traditional domains, a complementary function is conceivable in niches. Using the Bitcoin network poses several risks to customers, however. Since this network and financial services related to bitcoins are not regulated, costumers must take appropriate technical measures to protect their bitcoin holdings. In case of error and fraud, payments are difficult to reverse. Furthermore, the significant exchange rate fluctuations could pose a grave risk to bitcoin ownersâ wealth and discourage widespread use for monetary purposes. In a nutshell, at present, bitcoins can be regarded as speculative assets, and the Bitcoin network might inspire further innovation in payment systems and other applications.
Bitcoin is a crypto currency, a distributed peer-to-peer financial system. Well actually it is an electronic system which manages the provisional ownership of a strictly fixed supply of abstract fungible units which really works as a distributed property register or a digital notary service. This is not so different than managing the ownership of shares in traditional financial markets. Modern financial institutions increasingly just do NOT trust each other, they build co-operative robust and decentralized and increasingly transparent, electronic systems which are and able to both serve the diverse objectives of participants (e.g. traders) and uphold certain security policies. Is Bitcoin actually so brilliant to be called the Internet of money as it is sometimes claimed? Not quite. Consider just the question of speed. Super low latency transactions are a norm in the financial industry, and even ordinary people have access to super fast bank transfers and real-time credit card transactions. Bitcoin remains rather the horse carriage of money. In this paper we look at the question of fast transaction acceptance in bitcoin and other crypto currencies. We claim that bitcoin needs to change in order to be able to satisfy the most basic needs of modern users.
During 2013, the U.S. Treasury Department evoked the first use of the 2001 Patriot Act to exclude virtual currency provider Liberty Reserve from the U.S. financial system. This article will discuss: the regulation of virtual currencies; cybercrimes and payment systems; darknets, Tor and the âdeep webâ; Bitcoin; Liberty Reserve; Silk Road and Mt. Gox. Virtual currencies have quickly become a reality, gaining significant traction in a very short period of time, and are evolving rapidly. Virtual currencies present particularly difficult law enforcement challenges because of their: ability to transcend national borders in the fraction of a second; unique jurisdictional issues; and anonymity due to encryption. Due primarily to their anonymous characteristic, virtual currencies have been linked to numerous types of crimes, including facilitating marketplaces for: assassins; attacks on businesses; child exploitation (including pornography); corporate espionage; counterfeit currencies; drugs; fake IDs and passports; high yield investment schemes (Ponzi schemes and other financial frauds); sexual exploitation; stolen credit cards and credit card numbers; and weapons. Innovation in the pace of development of new currencies and technologies continue to create ongoing challenges for responsible users of technology and regulators alike. While technological advances create great opportunities to improve the health, living conditions, and general wellbeing of mankind; new technologies also create great challenges for nation states.
Bitcoins are scarce digital commodities that enable parties to transmit messages over a network that serves as a universal public ledger. Bitcoins fall within the definition of âcommodityâ under the Commodity Exchange Act (CEA) such that derivatives contracts that reference bitcoins are subject to regulation by the Commodity Futures Trading Commission. Like other derivatives, Bitcoin derivatives would likely not be subject to the full scope of regulation under the CEA to the extent such derivatives involve physical delivery (as opposed to cash settlement) or are nonfungible and not independently traded. In addition, Bitcoin swaps are currently too illiquid to be subject to mandatory clearing. A growing number of firms are offering Bitcoin derivatives, most of which are for retail traders. In addition to traditional derivatives that reference bitcoins, the Bitcoin (block chain) protocol can potentially enable automated derivatives contracts that securely trade, clear, and settle without the use of trusted intermediaries. The CFTC should consider an exemption for block chain derivatives that meet its policy objectives as a result of the rules that the underlying code applies to the transactions.
This paper discusses the potential and limitations of Bitcoin as a digital currency. Bitcoin as a digital asset has been extensively discussed from the viewpoints of engineering and security design. But there are few economic analyses of Bitcoin as a currency. Bitcoin was designed as a payments vehicle and as a store of value (or speculation). It has no use bar as money or currency. Despite recent enthusiasm for Bitcoin, it seems very unlikely that currencies provided by central banks are at risk of being replaced, primarily because of the market price instability of Bitcoin (i.e. the exchange rate against the major currencies). We diagnose the instability of market price of Bitcoin as being a symptom of the lack of flexibility in the Bitcoin supply schedule â a predetermined algorithm in which the proof of work is the major driving force. This paper explores the problem of instability from the viewpoint of economics and suggests a new monetary policy rule (i.e. monetary policy without a central bank) for stabilizing the values of Bitcoin and other cryptocurrencies.
The Bitcoin Market Potential Index conceptualizes and ranks the potential utility of bitcoin across 178 countries to show where the cryptocurrency has the greatest relative potential for adoption. The index utilizes a data set with 40 variables from the following areas: technology penetration, international remittances, inflation, informal economy, financial repression, financial crises (historical), and bitcoin penetration. Standardized and re-scaled country level data both indicate that Argentina and Sub-Saharan Africa are the country and region, respectively, where bitcoin has the greatest potential for adoption. It is argued that regulation could have an important effect on bitcoin adoption but that it should be excluded as an index variable for now due to insufficient data and uncertainty over its short-term directional impact and longer-term consequences.
Bitcoins are digital gold. They are a purely electronic commodity traded for speculative purposes as well as in exchange for goods and services. Just like physical gold, the relative price of bitcoins denominated in different currencies implies a nominal exchange rate. This is a departure from previous literature which treats bitcoin prices themselves as nominal exchange rates. I argue that treating prices as exchange rates is inappropriate as one would not consider the price of physical gold to be an exchange rate. Therefore, this paper characterizes the behavior of nominal exchange rates implied by relative bitcoin prices. I show that the implied nominal exchange rate is highly cointegrated with the nominal exchange rate determined in conventional foreign currency exchange markets. I also show that the direction of causality flows from the conventional markets to the bitcoin market and not vice-versa which can explain much of the volatility in bitcoin prices.
In this paper we discuss Bitcoin, the leader among the existing cryptocurrencies, to analyse its trends, success factors, current challenges and probable solutions to make it even better. In the introduction section, we discuss the history and working mechanism of Bitcoin. In the background section, we develop the ideas that evolved in the process of making a stable cryptocurrency. We also analyze the survey matrices of the present day cryptocurrencies. This survey clearly shows that Bitcoin is the clear winner among its kind. Section 3 is about the success factors of Bitcoin and the proceeding sections are a discussion about current challenges which pose as hurdles in making Bitcoin a better currency in the digital world. We finally discuss the balance between anonymity and reduced trust in the cryptocurrency world, before concluding the survey.
We present a thorough empirical analysis of market impact on the Bitcoin/USD exchange market using a complete dataset that allows us to reconstruct more than one million metaorders. We empirically confirm the "square-root law'' for market impact, which holds on four decades in spite of the quasi-absence of statistical arbitrage and market marking strategies. We show that the square-root impact holds during the whole trajectory of a metaorder and not only for the final execution price. We also attempt to decompose the order flow into an "informed'' and "uninformed'' component, the latter leading to an almost complete long-term decay of impact. This study sheds light on the hypotheses and predictions of several market impact models recently proposed in the literature and promotes heterogeneous agent models as promising candidates to explain price impact on the Bitcoin market -- and, we believe, on other markets as well.