Sean Foley, Jonathan R. Karlsen, TÄlis J. PutniĹĹĄ
Cryptocurrencies are among the largest unregulated markets in the world. We find that approximately one-quarter of bitcoin users are involved in illegal activity. We estimate that around $76 billion of illegal activity per year involve bitcoin (46% of bitcoin transactions), which is close to the scale of the U.S. and European markets for illegal drugs. The illegal share of bitcoin activity declines with mainstream interest in bitcoin and with the emergence of more opaque cryptocurrencies. The techniques developed in this paper have applications in cryptocurrency surveillance. Our findings suggest that cryptocurrencies are transforming the black markets by enabling âblack e-commerce.â Received June 1, 2017; editorial decision December 8, 2018 by Editor Andrew Karolyi. Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online.
David Rozas, Antonio Tenorio-FornĂŠs, Silvia DĂaz-Molina, Samer Hassan
Blockchain technologies have generated enthusiasm, yet their potential to enable new forms of governance remains largely unexplored. Two confronting standpoints dominate the emergent debate around blockchain-based governance: discourses characterized by the presence of techno-determinist and market-driven values, which tend to ignore the complexity of social organization; and critical accounts of such discourses which, while contributing to identifying limitations, consider the role of traditional centralized institutions as inherently necessary to enable democratic forms of governance. In this article, we draw on Ostromâs principles for self-governance of communities to explore the transformative potential of blockchain beyond such standpoints. We approach blockchain through the identification and conceptualization of six affordances that this technology may provide to communities: tokenization, self-enforcement and formalization of rules, autonomous automatization, decentralization of power over the infrastructure, increasing transparency, and codification of trust. For each affordance, we carry out a detailed analysis situating each in the context of Ostromâs principles, considering both the potentials of algorithmic governance and the importance of incorporating communitiesâ social practices into blockchain-based tools to foster forms of self-governance. The relationships found between these affordances and Ostromâs principles allow us to provide a perspective focused on blockchain-based commons governance.
Off-chain transaction channels represent one of the leading techniques to scale the transaction throughput in cryptocurrencies. However, the economic effect of transaction channels on the system has not been explored much until now. We study the economics of Bitcoin transaction channels, and present a framework for an economic analysis of the lightning network and its effect on transaction fees on the blockchain. Our framework allows us to reason about different patterns of demand for transactions and different topologies of the lightning network, and to derive the resulting fees for transacting both on and off the blockchain. Our initial results indicate that while the lightning network does allow for a substantially higher number of transactions to pass through the system, it does not necessarily provide higher fees to miners, and as a result may in fact lead to lower participation in mining within the system.
Driven by advances in data analytics, machine learning, and smart devices, financial technology is changing the way Canadians interact with the financial sector. The evolving landscape is further influenced by cryptocurrencies: non-fiat, decentralized digital payment systems, like Bitcoin, that operate outside the formal financial sector. While Bitcoin has garnered attention for facilitating criminal activity, including money laundering, terrorism financing, digital ransomware, weapons trafficking, and tax evasion, it is Bitcoin's underlying protocol, the blockchain, that represents an innovation capable of transforming financial services and challenging existing security, financial, and public safety regulations and policies. Canada's challenge is to find the right balance between oversight and innovation. Our paper examines these competing interests: we provide an overview of blockchain technologies, illustrate their potential in Canada and abroad, and examine the government's role in fostering innovation while concurrently bolstering regulations, maintaining public safety, and securing the integrity of financial systems.
Bitcoin, a peer-to-peer payment system and digital currency, is often involved in illicit activities such as scamming, ransomware attacks, illegal goods trading, and thievery. At the time of writing, the Bitcoin ecosystem has not yet been mapped and as such there is no estimate of the share of illicit activities. This paper provides the first estimation of the portion of cyber-criminal entities in the Bitcoin ecosystem. Our dataset consists of 854 observations categorised into 12 classes (out of which 5 are cybercrime-related) and a total of 100,000 uncategorised observations. The dataset was obtained from the data provider who applied three types of clustering of Bitcoin transactions to categorise entities: co-spend, intelligence-based, and behaviour-based. Thirteen supervised learning classifiers were then tested, of which four prevailed with a cross-validation accuracy of 77.38%, 76.47%, 78.46%, 80.76% respectively. From the top four classifiers, Bagging and Gradient Boosting classifiers were selected based on their weighted average and per class precision on the cybercrime-related categories. Both models were used to classify 100,000 uncategorised entities, showing that the share of cybercrime-related is 29.81% according to Bagging, and 10.95% according to Gradient Boosting with number of entities as the metric. With regard to the number of addresses and current coins held by this type of entities, the results are: 5.79% and 10.02% according to Bagging; and 3.16% and 1.45% according to Gradient Boosting.
Large stream of literature studies interconnectedness among various assets that are relevant in current global markets. Transmission of shocks between cryptocurrencies and traditional asset classes is, however, not understood at all, but should not be ignored due to increasing influence of cryptocurrencies in recent years. In this paper, we study how shocks between the most liquid representatives of the traditional asset classes including commodities, foreign exchange, stocks, financials, and cryptocurrencies are being transmitted. Generally, we document very low level of connectedness between the main cryptocurrency and other studied assets. The only exception is gold which receives substantial amount of shocks from cryptocurrency market. Our findings are important since we show that cryptocurrencies play role in global markets, and the results could also be useful in portfolio diversification schemes. Moreover, we find significant positive asymmetry in spillovers between the studied assets, which is in contradiction to previous studies conducted on assets from a single asset class.
This chapter examines the emergence of the digital financial inclusion paradigm, including the role of new communicative technologies in facilitating inclusive innovation practices. It examines the âmobile money revolutionâ in East Africa, exploring in particular the central role of local practices of money management and user innovations in the success of that digital finance initiative. Building on the analysis of the impact of mobile money, the chapter considers emerging practices of person-to-person payments based on block-chain technologies in developing economies. It examines the conceptually novel approaches to sending and receiving migrant remittances made possible by the blockchain technology, which include new digital forms of money, novel payment infrastructures, and new types of remittance actors such as fintech start-ups and other non-bank financial service providers. The chapter demonstrates that the social meaning attached to actual financial practice helps to illuminate the broader impact of the digital financial technologies as they move through the material and human infrastructures.
Purpose The purpose of this paper is to determine if Bitcoin transactions could be de-anonymised by analysing the Bitcoin blockchain and transactions conducted through the blockchain. In addition, graph analysis and the use of modern social media technology were examined to determine how they may help reveal the identity of Bitcoin users. A review of machine learning techniques and heuristics was carried out to learn how certain behaviours from the Bitcoin network could be augmented with social media technology and other data to identify illicit transactions. Design/methodology/approach A number of experiments were conducted and time was spend observing the network to ascertain how Bitcoin transactions work, how the Bitcoin protocol operates over the network and what Bitcoin artefacts can be examined from a digital forensics perspective. Packet sniffing software, Wireshark, was used to see whether the identity of a user is revealed when they set up a wallet via an online wallet service. In addition, a block parser was used to analyse the Bitcoin client synchronisation and reveal information on the behaviour of a Bitcoin node when it joins the network and synchronises to the latest blockchain. The final experiment involved setting up and witnessing a transaction using the Bitcoin Client API. These experiments and observations were then used to design a proof of concept and functional software architecture for searching, indexing and analyzing publicly available data flowing from the blockchain and other big data sources. Findings Using heuristics and graph analysis techniques show us that it is possible to build up a picture of behaviour of Bitcoin addresses and transactions, then utilise existing typologies of illicit behaviour to collect, process and exploit potential red flag indicators. Augmenting Bitcoin data, big data and social media may be used to reveal potentially illicit financial transaction going through the Bitcoin blockchain and machine learning applied to the data sets to rank and cluster suspicious transactions. Originality/value The development of a functional software architecture that, in theory, could be used to detect suspicious illicit transactions on the Bitcoin network.
Ramiro Daniel Camino, Radu State, Leandro Montero, Petko Valtchev
Banks and financial institutions around the world must comply with several policies for the prevention of money laundering and in order to combat the financing of terrorism. Nowadays, there is a raise in the popularity of novel financial technologies such as digital currencies, social trading platforms and distributed ledger payments, but there is a lack of approaches to enforce the aforementioned regulations accordingly. Software tools are developed to detect suspicious transactions usually based on knowledge from experts in the domain, but as new criminal tactics emerge, detection mechanisms must be updated. Suspicious activity examples are scarce or nonexistent, hindering the use of supervised machine learning methods. In this paper, we describe a methodology for analyzing financial information without the use of ground truth. A user suspicion ranking is generated in order to facilitate human expert validation using an ensemble of anomaly detection algorithms. We apply our procedure over two case studies: one related to bank fund movements from a private company and the other concerning Ripple network transactions. We illustrate how both examples share interesting similarities and that the resulting user ranking leads to suspicious findings, showing that anomaly detection is a must in both traditional and modern payment systems.
Bitcoinsâ technology brings a new level of innovation to business and communication across the world. However, the advantages of a virtual currency payment system face the threat from criminal activities occurring over a pseudonymous network where there is virtually no current regulation to cover illegal transactions. The current situation in Georgia is as follows: the second Bitcoinâs processing datacenter has opened in Georgia. While the virtual money is new even in developed countries, more unusual it is for Georgia, where local economists are more skeptical toward cryptocurrency. Therefore, they believe that electronic money is not controlled by any central bank that gives a lot of opportunities for illegal transactions. According to the Georgian experts, bitcoin is a very risky currency that can be used for money laundering, as it is completely uncontrolled. However, the Georgian central bank system claims that bitcoins are not dangerous, and the lack of awareness gives rise to talk about money laundering. The biggest challenge seems to be regulation of Bitcoin without hindering the potential for growth. While there is usually certainly a chance that Bitcoin could fail or be pushed out of existence by a more innovative technology, policymakers must be careful not to hinder a technology that could change the way global economy functions.
Bitcoin is an emerging financial technology that is gaining a lot of popularity all over the world and starting to change the way people make financial transaction. In Indonesia however, bitcoin is more famous for its negative issue, such as money laundering, rather than its usage in financial transaction. One interesting fact to observe is the absence of regulations that explicitly governs the usage of bitcoins. This paper analyzes the factors influencing Indonesian authorities in defining regulations for bitcoins and how the existing regulations left open some opportunities for a bad guy to perform money laundering with the help of bitcoins. A qualitative approach is used in this research for data collection and analysis. Interview with two experts representing bitcoin exchange company and legal consultant was conducted in data collection. The outcome of this research is to find out vulnerabilities in bitcoin that allows money laundering and give suggestions on how to prevent money laundering with bitcoin from the perspective of regulations and bitcoin company in Indonesia.
When Bitcoin was first introduced to the world in 2008 by an enigmatic programmer going by the pseudonym Satoshi Nakamoto, it was billed as the world's first decentralized virtual currency. Offering the first credible incarnation of a digital currency, Bitcoin was based on the principal of peer to peer transactions involving a complex public address and a private key that only the owner of the coin would know. This paper will seek to investigate how the usage and value of Bitcoin is affected by current events in the cyber environment. Is an advancement in the digital security of Bitcoin reflected by the value of the currency and conversely does a major security breech have a negative effect? By analyzing statistical data of the market value of Bitcoin at specific points where the currency has fluctuated dramatically, it is believed that trends can be found. This paper proposes that based on the data analyzed, the current integrity of the Bitcoin security is trusted by general users and the value and usage of the currency is growing. All the major fluctuations of the currency can be linked to significant events within the digital security environment however these fluctuations are beginning to decrease in frequency and severity. Bitcoin is still a volatile currency but this paper concludes that this is a result of security flaws in Bitcoin services as opposed to the Bitcoin protocol itself.
With recent alarm and focus on Bitcoin , many researchers tried to come up with studies that are related to Bitcoin. This paper tries to do the same but with a focus on the area of Islamic finance. We try to relate Bitcoin and Islamic index to find if there is any relation between these two assets and to find which will stand out if they are put in one portfolio. Since both assets are deemed to be of high risk in nature, it is an interesting topic to be investigated especially if they are put together. This analysis was carried out using the standard time-series approach of cointegration, VECM and VDC. The empirical results evidenced that Bitcoin and Islamic index are theoretically related as they are cointegrated. Another interesting finding in this study unveiled that Islamic index will be more influential than Bitcoin if they are put in one portfolio.
Rune Tevasvold Aune, Adam Krellenstein, Maureen OâHara, Ouziel Slama
This article examines information leakage when trading in distributed ledgers. We show how the lack of time priority in the period between the publication of a transaction and its validation by miners or designated participants can expose a transactionâs footprint to the market, resulting in potential front-running and manipulation. We propose a cryptographic approach for solving information leakage problems in distributed ledgers that relies on using a hash (or fingerprint) to secure time priority, followed by a second communication that reveals more features of the underlying market transactionâin effect using a transactionâs fingerprint to hide its footprint. Solving the information leakage problem greatly expands the potential applications of private distributed ledger technology to include trading. <b>TOPICS:</b>Quantitative methods, exchanges/markets/clearinghouses
Present paper explains role of the Bitcoin and its involvement in economic activity worldwide, using practical examples of real business models, reflects the modern views of legislators and judicial bodies on local (selective countries legislation and court practice) and international level (European Union legislation and international court practice), which are formed after Bitcoinâs fast widespread in 2012. Current research examines in details various definition of the Bitcoin, used by legislators to place Bitcoin in already existing legal frames â virtual money, property, commodity or financial instruments, which has significant importance to legislators worldwide to regulate business activity related to Bitcoin: licensing of institutions issuing Bitcoin, if it is defined as virtual money; Bitcoinâs place in stock market, if it is defined as security or financial instrument; or transfer of property rights, if Bitcoin is defined as commodity or property. Moreover this paper underlines importance of amendments acceptance, based on certain Bitcoinâs definition, to prevent money laundering, financial support providing to terrorism, to straighten financial market and consumer protection procedures.
We investigate how distributed denial-of-service (DDoS) attacks and other disruptions affect the Bitcoin ecosystem. In particular, we investigate the impact of shocks on trading activity at the leading Mt. Gox exchange between April 2011 and November 2013. We find that following DDoS attacks on Mt. Gox, the number of large trades on the exchange fell sharply. In particular, the distribution of the daily trading volume becomes less skewed (fewer big trades) and had smaller kurtosis on days following DDoS attacks. The results are robust to alternative specifications, as well as to restricting the data to activity prior to March 2013, i.e., the period before the first large appreciation in the price of and attention paid to Bitcoin.
Purpose The purpose of this paper is to critically analyse research surrounding the anonymity of online transactions using Bitcoin and report on the feasibility of law enforcement bodies tracing illicit transactions back to a userâs real-life identity. Design/methodology/approach The design of this paper follows on from the approach taken by Reid and Harrigan (2013) in determining whether identifying information may be collated with external sources of data to identify individual users. In addition to conducting a detailed literature review surrounding the anonymity of users, and the potential ability to track transactions through the blockchain, four Bitcoin exchange services are examined to ascertain whether information provided at the sign-up stage is sufficiently verified and reliable. By doing so, this research tests the ability for law enforcement to reasonably rely upon this information when attempting to prosecute individuals. Additionally, by submitting fake information for verification, the plausibility of these services accepting fraudulent or illegitimate information is also tested. Findings It may be possible to identify and prosecute bad actors through the analysis of transaction histories by tracing them back to an interaction with a Bitcoin exchange. However, the compliance and implementation of anti-money laundering legislation and customer identification security standards are insufficiently used within some exchange services, resulting in more technologically adept, or well-funded, criminals being able to circumvent identification controls and continue to transact without revealing their identities. The introduction of and compliance with know-your customer and customer due diligence legislation is required before law enforcement bodies may be able to accurately rely on information provided to a Bitcoin exchange. This paper highlights the need for research to be undertaken to examine the ways in which criminals are circumventing identity controls and, consequently, financing their illicit activities. Originality/value By ascertaining the types of information submitted by users when exchanging real currency for virtual currency, and seeing whether this information may be accepted despite being fraudulent in nature, this paper elucidates the reliability of information that law enforcement bodies may be able to access when tracing transactions back to an individual actor.
Neil Gandal, JT Hamrick, Tyler Moore, Tali Oberman
To its proponents, the cryptocurrency Bitcoin offers the potential to disrupt payment systems and traditional currencies. It has also been subject to security breaches and wild price fluctuations. This paper identifies and analyzes the impact of suspicious trading activity on the Mt. Gox Bitcoin currency exchange, in which approximately 600, 000 bitcoins (BTC) valued at $188 million were fraudulently acquired. During both periods, the USD-BTC exchange rate rose by an average of four percent on days when suspicious trades took place, compared to a slight decline on days without suspicious activity. Based on rigorous analysis with extensive robustness checks, the paper demonstrates that the suspicious trading activity likely caused the unprecedented spike in the USD-BTC exchange rate in late 2013, when the rate jumped from around $150 to more than $1, 000 in two months.
Since its creation in 2009, the electronic currency Bitcoin has generated volumes of online debate in the business press. While there have been plenty of economic arguments situating it as a financial bubble about to collapse including from Nobel Prize winning economists, its price value has proven to be more durable than many have predicted. To explain this durability, Karpikâs conception of market singularities is used to understand the Bitcoin phenomenon by outlining the beliefs that maintain Bitcoinâs status as a volatile financial asset. Market singularities are markets for particular kinds of goods and services that are of uncertain and incommensurable value. Singularities markets have communities of followers and a distinctive belief system that ascribes value to a particular product, service, or asset. Developing Karpikâs conception, the paper explores the libertarian political belief system that surrounds Bitcoinâs status as a financial asset. I also outline some political tensions within the electronic currency community concerning governance and centralisation.
Abstract Stratum, the de-facto mining communication protocol used by blockchain based cryptocurrency systems, enables miners to reliably and efficiently fetch jobs from mining pool servers. In this paper we exploit Stratumâs lack of encryption to develop passive and active attacks on Bitcoinâs mining protocol, with important implications on the privacy, security and even safety of mining equipment owners. We introduce StraTap and ISP Log attacks, that infer miner earnings if given access to miner communications, or even their logs. We develop BiteCoin, an active attack that hijacks shares submitted by miners, and their associated payouts. We build BiteCoin on WireGhost, a tool we developed to hijack and surreptitiously maintain Stratum connections. Our attacks reveal that securing Stratum through pervasive encryption is not only undesirable (due to large overheads), but also ineffective: an adversary can predict miner earnings even when given access to only packet timestamps. Instead, we devise Bedrock, a minimalistic Stratum extension that protects the privacy and security of mining participants. We introduce and leverage the mining cookie concept, a secret that each miner shares with the pool and includes in its puzzle computations, and that prevents attackers from reconstructing or hijacking the puzzles. We have implemented our attacks and collected 138MB of Stratum protocol traffic from mining equipment in the US and Venezuela. We show that Bedrock is resilient to active attacks even when an adversary breaks the crypto constructs it uses. Bedrock imposes a daily overhead of 12.03s on a single pool server that handles mining traffic from 16,000 miners.