Blockchain Papers

Dmitri Kosten

No abstract is available for this record.

Robert Kurek

No abstract is available for this record.

Kinga Kądziołka

No abstract is available for this record.

Michael B. Abramowicz

No abstract is available for this record.

Jason Paul Cruz, Yuichi Kaji

The role-based access control (RBAC) is a natural and versatile model of the access control principle. In the real world, it is common that an organization provides a service to a user who owns a certain role that was issued by a different organization. However, such a trans-organizational RBAC is not common in a computer network because it is difficult to establish both the security that prohibits malicious impersonation of roles and the flexibility that allows small organizations/individual users to fully control their own roles. This study proposes a system that makes use of Bitcoin technology to realize a trans-organizational RBAC mechanism. Bitcoin, the first decentralized digital currency, is a payment network that has become a platform for innovative ideas. Bitcoin’s technology, including its protocol, cryptography, and open-source nature, has built a good reputation and has been applied in other applications, such as trusted timestamping. The proposed system uses Bitcoin technology as a versatile infrastructure to represent the trust and endorsement relationship that are essential in RBAC and to realize a challenge-response authentication protocol that verifies a user's ownership of roles.

Joshua Elkington

Bitcoin is a decentralized peer-to-peer payment system that has the potential to disrupt the financial industry. In order for the Bitcoin network to function properly, people within the network need to follow the protocol and contribute computing power. However, selfish strategies can be used to disproportionately increase one’s payoff relative to their computational power. Three approaches are used to analyze selfish mining strategies in the Bitcoin network in order to determine when this strategy will dominate.

Divya Rana, Syed Md Faisal Ali Khan, Arvind Arahant, Jitender Kumar Chaudhary

This study investigates the concept of green cryptocurrencies as a potential solution to mitigate the ecological footprint associated with traditional cryptocurrencies. It explores their viability as a sustainable alternative to traditional currencies. The rising popularity of cryptocurrencies has brought about concerns regarding their environmental impact, particularly due to the energy-intensive nature of mining and transactions.In conclusion, the importance of exploring sustainable alternatives to traditional cryptocurrencies emphasizes the potential of green cryptocurrencies to address environmental concerns.It discusses the growing awareness within the cryptocurrency community and the general public regarding the urgent need to address these issues. Green cryptocurrencies employ alternative consensus mechanisms, such as Proof-of-Stake (PoS) or energy-efficient algorithms, and utilize renewable energy sources for mining and transactions.

Paul McCullum

Bitcoin, a virtual currency created in 2009 by an individual or group using the alias Satoshi Nakamoto, is based on a decentralized peer-to-peer system. Transactions are made with no intermediary. There are no banks involved, little to no transaction fees, and transactions are almost instantaneous. Transactions are verified by network nodes, and the network uses a public ledger called the block chain to record transactions. There is no central repository or administrator. Treasury categorizes it as a decentralized virtual currency. As public acceptance increases, so too does the number of merchants willing to accept bitcoin as a form of payment. But even though the public is slowly embracing bitcoin as a form of payment (thus giving it characteristics of a currency), public officials continue to struggle with the question of whether bitcoin is a currency — and therefore subject to appropriate currency regulations — or if it is simply property, making transactions in bitcoin more akin to barter.

Ittay Eyal

An open distributed system can be secured by requiring participants to present proof of work and rewarding them for participation. The Bitcoin digital currency introduced this mechanism, which is adopted by almost all contemporary digital currencies and related services. A natural process leads participants of such systems to form pools, where members aggregate their power and share the rewards. Experience with Bitcoin shows that the largest pools are often open, allowing anyone to join. It has long been known that a member can sabotage an open pool by seemingly joining it but never sharing its proofs of work. The pool shares its revenue with the attacker, and so each of its participants earns less. We define and analyze a game where pools use some of their participants to infiltrate other pools and perform such an attack. With any number of pools, no-pool-attacks is not a Nash equilibrium. We study the special cases where either two pools or any number of identical pools play the game and the rest of the participants are uninvolved. In both of these cases there exists an equilibrium that constitutes a “tragedy of the commons” where the participating pools attack one another and earn less than they would have if none had attacked. For two pools, the decision whether or not to attack is the miner’s dilemma, an instance of the iterative prisoner’s dilemma. The game is played daily by the active Bitcoin pools, which apparently choose not to attack. If this balance breaks, the revenue of open pools might diminish, making them unattractive to participants.

Kristian Đokić, Mirjana Radman Funarić, Katarina Potnik Galić

No abstract is available for this record.

Алексей Чурилов

Bitcoins and their use are a very actual issue, especially with high popularity and high cost of Bitcoins. Number of Bitcoin’s transactions increasing day to day. But many individuals and business owners do not understand what is Bitcoin, how it works and how could it be used in business. This article discusses the nature of Bitcoin, a decentralized, anonymous and largely unregulated virtual currency, its legal status and use in business. The article includes examination of both advantages and disadvantages of Bitcoin and international regulation of legal status and taxation of this currency.

J Wonglimpiyarat

This paper is concerned with the new Darwinism of the payment system. The researcher discusses the payment system to understand if Bitcoin would replace our cash-based society. The analysis is based on the technology S-curve and Schumpeter’s model of economic development. At present, there are problems hindering Bitcoin innovation to achieve a wide adoption as the innovation is not well received by the government central banks around the world. It is interesting to see that the swing of S-curves is not strong enough to cause a paradigm shift according to the Schumpeterian concept of creative destruction. The results have shown parallel S-curve trajectories of electronic money innovations signifying a move from a cash-based economy towards a less cash society. The study provides useful implications to support the diffusion of Bitcoin innovation.

Ramesh Subramanian, Theo Chino

This paper focuses on the evolution of cryptocurrencies. It traces the history of early cryptography, the ‘cypherpunk’ movement, and how the work of some cyber libertarians and cryptographers enabled the emergence of popular cryptocurrencies. The paper then focuses on Bitcoin. It delves into the technology behind the Bitcoin architecture and shows how exactly this technology works. The paper then does an analysis of security and regulatory considerations that affect the growth of Bitcoin-based businesses. The paper concludes with some suggestions for future work in the area.

Nicolas T. Courtois, Pinar Emirdag, Zhouyixing Wang

In this paper we study the question of centralisation in bitcoin digital currency. In theory bitcoin has been designed to be a totally decentralized distributed system. Satoshi Nakamoto has very clearly postulated that each node should be collecting recent transactions and trying to create new blocks (Satoshi08). In bitcoin transactions are aggregated in block in order to authenticate them and form an official ledger and history of bitcoin transactions. In practice as soon as expensive ASIC bitcoin miners have replaced general-purpose hardware, production of bitcoins and the validation of transactions has concentrated in the hands of a smaller group of people. Then at some moment in early 2012 an important decision was taken: the Stratum protocol was designed (Palatinus12) which took a deliberate decision to move the power of selecting which transactions are included in blocks from miners to pool managers. The growing difficulty of mining and large standard deviation in this process (Rosenfeld13; CourtoisBahack14) made that majority of miners naturally shifted to pooled mining. At this moment bitcoin ceased being a decentralized democratic system. In this paper we survey the question of a 51% attacks and show that there is a large variety of plausible attack scenarios. In particular we study one particularly subversive attack scenario which depends on non-trivial internal details of the bitcoin hashing process. How does it compare with the current mining practices? We have study the Stratum protocol in four popular real-life mining configurations. Our analysis shows that pools could very easily cheat the majority of people. However the most subversive versions of the attack are NOT facilitated and could potentially be detected.

Filipe Drebes Scarinci

Os mais diversos sistemas monetários foram experimentados pela socidade até chegarmos no modelo atual e há poucos indícios de que este deva ser o último e definitivo. Existe uma insatisfação com o sistema vigente e com o grande poder que as autoridades monetárias adquiriram nos últimos anos. Novos modelos vêm surgindo nas mais diversas áreas, e uma das alternativas que se desenha para o arranjo financeiro é o Bitcoin, um sistema monetário completamente descentralizado, que se utiliza da tecnologia pessoa-a-pessoa para transformar o modo como os indivíduos se relacionam. O trabalho se propõe a analisar a origem, as características, o funcionamento e as inovações trazidas pelo sistema Bitcoin, comparando a criptomoeda às outras moedas tradicionais estudadas na literatura econômica. Em especial, trata de analisar a factibilidade do Bitcoin enquanto moeda.

Ignacio Más, David Lee Kuo Chuen

No abstract is available for this record.

Benedikt C. Eikmanns, Philipp Sandner

Despite a high volatility and the recent fall in price, more and more merchants and consumers adopt Bitcoin. The virtual currency might be standing at its critical point to reach the early majority of adopters. This paper examines whether an application called ChangeTip has the potential to catalyze the breakthrough of Bitcoin. We assume a strong linkage between the diffusion of ChangeTip and Bitcoin so that we can directly deduce the impact of this application on Bitcoin. Results from a conducted online survey of 210 potential early adopters indicate that the diffusion of ChangeTip has the potential to advance the diffusion of Bitcoin to mainstream markets. We found that performance expectancy is the key driver for the intention to recommend ChangeTip. Also, effort expectancy, social influence and facilitating conditions are important factors for recommending ChangeTip. Concerning the intention to use ChangeTip in the future, performance expectancy and social influence are the main drivers. Furthermore, facilitating conditions are important for using ChangeTip. In addition, an analysis of the non-user of Bitcoin and ChangeTip was conducted. Theoretical and practical implications of these results are discussed.

Gianluca Miscione, Donncha Kavanagh

No abstract is available for this record.

Liam Morris

Cash in the real world allows for parties to exchange currency without the need to go through some sort of central authority. One person, Alice, can simply hand cash over to another person, Bob. In this transaction the only two people that have knowledge of this exchange are Alice and Bob. Until recently there was no electronic equivalent to this exchange. In 1982 David Chaum proposed a system of anonymous electronic cash based on blind signatures, and in 1990 founded DigiCash as an electronic cash company. There were a few banks that implemented electronic cash systems, but these banks and DigiCash ultimately went bankrupt in 1997 and 1998 despite the enthusiasm surrounding anonymous electronic cash. Between 1998 and 2008 there were no successful implementations of electronic cash that offer a decentralized, anonymous, and untraceable system.\nIn 2008 a paper was published by Satoshi Nakamoto on the cryptocurrency known as Bitcoin. A cryptocurrency is a form of electronic cash backed by mathematical and cryptographic constructs, unlike traditional currency which was historically backed by gold or silver. Cryptocurrencies have seen rising popularity in recent years due to their decentralized, distributed, peer-to-peer protocols. Part of this rising popularity is also attributable to the supposed anonymity of these protocols; however, due to the public transaction history required for these protocols and the fact that transactions are pseudonymous and not purely anonymous, this supposed anonymity does not exist. While the systems may achieve the goal of decentralized currency it does not achieve the goal of untraceability. In this thesis we analyze the technical implementations of Bitcoin and other cryptocurrencies to determine the level of anonymity provided by these protocols. We also analyze proposed improvements for their feasibility.

J.A. Bergstra

Six assertions concerning the status of Bitcoin are formulated and defended: (i) Bitcoin is not and will not become a currency-like informational commodity, (ii) currency-like informational commodities that aren’t currencies must be frauds, (ii) specific BTC amounts may become monetized and thus may be turned into financial assets, (iii) currently no BTC amounts are monetized in any currency area and therefore none are financial assets, (iv) by means of burocratic steps only some BTC volumes can be turned in to an informational currency within a given currency area, modified client software is not required for that step, (v) if a specific amount of BTC qualifies as currency, it also qualifies as money, (vi) moneyness of Bitcoin, or rather of a specific occurrence of an amount of BTC, should be questioned only after one has agreed positively on its status as a financial asset, and negatively on its status as an amount of currency. Factions in the Bitcoin promoting movement are viewed from a perspective of organizational multi-threading. Different factions of the Bitcoin movement may wish to see status issues about Bitcoin settled in different ways. Overall consistency in these matters should not be expected from the union of factions in the Bitcoin movement.

Daniel Folkinshteyn, Mark M. Lennon, Tim Reilly

No abstract is available for this record.

Nirupama Devi Bhaskar, Lam Pak Nian, David Lee Kuo Chuen

No abstract is available for this record.

Hanna Hałaburda, Miklós Sárváry

No abstract is available for this record.

Nick Vogel

Bitcoin’s popularity increased as its value increased and people became excited about the prospect of a trustless, decentralized currency that could be used on the Internet. Within the last two years, however, people and organizations began exploiting the potential of the block chain that powers the bitcoin network. These people realized that the block chain—a transparent public ledger that cannot be altered—can be used for more than digital currency. One such organization calls itself Ethereum and its developers plan to use block chains to allow decentralized autonomous applications to operate free of government censorship or corruption. While such a network would have a profound effect on society—allowing trustless voting, uncensored social networking and the like—its impact on copyrights could be devastating. This paper argues that the emerging, decentralized Internet (also known as Web 3.0) will be the straw that breaks the copyright owner’s back. This paper argues that, with block chain technology and decentralized applications, those buying and selling unauthorized copies of copyrighted material cannot be subject to court injunctions; making enforcement of copyrights nearly impossible on a decentralized Internet. This paper then proposes that copyright holders get out in front of the problem by embracing a decentralized Internet. This can only be done by drastically reducing the price of copyright licenses. In other words, by offering cheap licenses at the dawn of Web 3.0, copyright holders can instill a sense that it’s better to be safe than sorry when it comes to the ongoing struggle between technology and copyrights.