Blockchain Papers

Charles Cuvelliez

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Eirik Stokke, Tarje Størksen Otre

I denne utredningen ønsker vi å belyse det økonomisk innovative fenomenet bitcoin. Målet med oppgaven er å få klarhet i hva bitcoin er, og med grunnlag i dette undersøke om det er en boble. I første del av utredningen presenterer vi det tekniske som ligger bak og ser på hvordan det fungerer i det økonomiske markedet. Med bakgrunn i fremlagte teorier om valuta, råvare, betalingssystemer og svindler, analyserer vi hvilken definisjon bitcoin passer best innunder. Analysen viser oss at bitcoin ser ut til å hovedsakelig fungere som spekuleringsobjekt, men at det i fremtiden kan være som betalingssystem. Dette begrunnes i lave transaksjonskostnader, noe som muliggjør mikrotransaksjoner.\nI den andre delen av utredningen forsøker vi å besvare hovedproblemstillingen vår, hvorvidt bitcoin er en boble. Vi presenterer relevant bobleteori, herunder teorier om rasjonelle og irrasjonelle bobler. Volatilitetsberegninger viser oss at bitcoin har en daglig historisk volatilitet i tidsrommet 1.januar 2012 – 26.mars 2014 på 8,5%. Vi har videre beregnet korrelasjonen mellom bitcoin sin prisutvikling og antall søk i Google til å være 0,96. Beregningene er benyttet til å analysere bitcoin opp mot bobleteori. Analysen viser oss tendenser til at det investeres i bitcoin i håp om en prisøkning i morgen, og at prisen samsvarer med publisiteten. Dette er klare indikasjoner på at markedsprisen ikke reflekterer aktivumets fundamentale faktorer. Basert på analysen fremlegger vi også våre egne beregninger på minste fundamentale verdi til bitcoin, en verdi på $252,74.\nVåre analyser og funn sett opp mot relevant bobleteori tyder på at bitcoin er en boble. Fundamental verdi er ikke gjenspeilet i prisen, man kjøper i håp om gevinst i morgen og prisen korrelerer sterkt med publisiteten.\nØkonometrisk testing er gjennomført i SPSS, mens øvrig databehandling er gjennomført i Excel.

Simanti Bandyopadhyay

TWith the help of the available literature, the paper attempts to assess critically the main problems of municipal finances in India and to bring out the challenges that the municipalities face with respect to revenue generation and expenditure management. The main findings suggest that the urban local bodies in India are confronted with lack of proper decentralization of functions and finances, inadequate revenue generation, expenditure shortfalls leading to poor service delivery. It also analyses the suggestions and recommendations that have been offered in the literature to cope with these critical challenges relating to urban finance.

Stephen L. Reed

A hard-fork reconfiguration of the peer to peer Bitcoin network is described that substitutes tamper-evident logs and proof-of-stake consensus for proof-of-work consensus. The block creation rewards and transaction fees are reallocated to establish and staff a secure financial data network capable of handling the world's transactions with subsecond response time. The new system pays dividends to stake-offering bitcoin holders. In contrast to Satoshi Nakamoto's mesh network consisting of competing peers, this system uses an enterprise class network that is efficient, robust, and scalable, consisting of cooperating peers. The network backbone nodes host trustless nomadic agents. Thousands of distributed full nodes are paid to replicate a singleton blockchain built upon every 10 minutes by a nomadic mint agent whose actions are verified by its peers. This arrangement enables immediate acknowledgment to an issuing node that its transaction has been accepted. Less effort means that subsidized transaction costs will be lower. Network reconfiguration enables the processing of numerous microtransactions. Stake-weighted distributed consensus is achieved when necessary with less than one-half arbitrarily faulty nodes. Important invariants of the Satoshi Social Contract between core developers and users are maintained: The reward schedule, the blockchain format, the fixed number of bitcoins, and the decentralized, trustless protocol are untouched. The system remains a global distributed database, with additions to the database by consent of the majority, based on a set of transparent rules they follow.

Pavel Ciaian, Miroslava Rajčániová, d’Artis Kancs

This is the first article that studies BitCoin price formation by considering both the traditional determinants of currency price, e.g., market forces of supply and demand, and digital currencies specific factors, e.g., BitCoin attractiveness for investors and users. The conceptual framework is based on the Barro (1979) model, from which we derive testable hypotheses. Using daily data for five years (2009–2015) and applying time-series analytical mechanisms, we find that market forces and BitCoin attractiveness for investors and users have a significant impact on BitCoin price but with variation over time. Our estimates do not support previous findings that macro-financial developments are driving BitCoin price in the long run.

Fuchun Guo, Yi Mu, Willy Susilo

In this paper, we propose a novel cryptographic notion called subset membership encryption (SME), and provide a very efficient SME scheme. Given a system parameter generated by an encryptor (Alice), a decryptor (Bob) generates a randomized privacy-preserved attribute token P(G) from a set of attributes G. A message is encrypted using an attribute set A chosen by Alice and P(G) provided by Bob. It requires that A is a subset of G for Bob to decrypt the message. We propose a very efficient SME scheme, where both the size of P(G) and ciphertext are short and independent of G and A. In particular, it has three useful and practical applications to oblivious transfer as follows. 1) k-Out-of-n Oblivious Transfer (OT): SME can be naturally applied to a two-round OT, which features a great communication efficiency especially for the receiver, where the receiver only sends two group elements to the message sender. 2) Priced Oblivious Transfer (POT): Our POT protocol allows a buyer to purchase any number of items in each transaction and hide selected items, price and balance from the vendor. In comparison with previous POT protocols, our protocol is more flexible and eliminates the restriction that a buyer can only purchase one item in a transaction. Our POT scheme is very efficient since it does not require any zero-knowledge proof or homomorphic encryption. 3) Restricted Priced Oblivious Transfer (RPOT): We introduce a novel POT named RPOT where a vendor can set restrictions on items or prices in POT. For example, a seller could offer a discounted price to those buyers who have purchased some specific items previously from the same seller.

Mattijs Lambooij

Bitcoins are increasingly being used in commercial transactions. Thinking about the tax consequences thereof is, however, still in its infancy. This article discusses the current state of play and reports on some guidance already provided by tax authorities. The key issue to consider seems to be the VAT treatment of bitcoin transactions between two entrepreneurs.

Samantha Xu

Consider the radial nonlinear wave equation $-\partial_t^2 u + Δu = u^3$, $u :\mathbb{R}_t \times \mathbb{R}_x^3 \to \mathbb{R}$, $u(t,x) = u(t,|x|)$. In this paper, we construct a Gibbs measure for this system and prove its invariance under the flow of the NLW. In particular, we are in the infinite volume setting. For the finite volume analogue, specifically on the unit ball with zero boundary values, an invariant Gibbs measure was constructed by Burq, Tvetkov, and de Suzzoni as a Borel measure on super-critical Sobolev spaces. In this paper, we advocate that the finite volume Gibbs measure be considered on a space of weighted Hölder continuous functions. The measure is supported on this space and the NLW is locally well-posed there, a counter-point to the Sobolev super-criticality noted by Burq and Tzvetkov. Furthermore, the flow of the NLW leaves this measure invariant. We use a multi-time Feynman--Kac formula to construct the infinite volume limit measure by computing the asymptotics of the fundamental solution of an appropriate parabolic PDE. We use finite speed of propagation and results from descriptive set theory to establish invariance of the infinite volume measure. To the best of our knowledge, this paper provides the first construction and proof of invariance of a Gibbs measure in infinite volume outside of the 1D case.

Björn Ingi Björnsson

No abstract is available for this record.

Martina Halásková, Renata Halásková

Successful decentralisation joins public finances and fiscal authority with the responsibility for providing services with functions of local government. The paper deals with decentralisation of public administration in EU countries, focusing on fiscal decentralisation and local government expenditures, allocated for financing the requirements of local and regional sector. Attention is paid to theoretical aspects, reform tendencies, approaches and measuring fiscal decentralisation, but also to the role of local budgets when providing for public services. The research proper is concentrated on the extent of expenditure decentralisation in EU countries over the years 2001-2012 and on mutual relations of local government expenditures, seen as % of general government expenditures, and as % of GDP.

Shawna Grosskopf, Kathy Hayes, Lori L. Taylor

Abstract In this paper we explore some of the policy issues related to the provision of primary and secondary education in the United States from an economic standpoint. We begin with stylized facts and a brief reference to the uniquely decentralized financing and delivery of public education in the United States, and the resulting issues of equity and quality that arise. As a reference point we review the basic efficiency and equity arguments for public financing and the provision of public goods in general, and education specifically, both of which suggest that current practices are unlikely to be efficient or equitable. These are issues that have motivated a number of policy avenues—the accountability movement, including No Child Left Behind, as well as recent efforts to establish higher and uniform standards for our public schools. We then turn to the sizable body of literature assessing school performance. We include an empirical example of this approach for Texas primary and secondary schools, with a focus on the many challenging issues involved with modeling and assessing educational performance. Our application demonstrates that research findings are highly sensitive to modeling choices, suggesting that a mixed methods approach is most likely to lead to effective education reforms.

Nicolas T. Courtois

In this paper we revisit some major orthodoxies which lie at the heart of the bitcoin crypto currency and its numerous clones. In particular we look at The Longest Chain Rule, the monetary supply policies and the exact mechanisms which implement them. We claim that these built-in properties are not as brilliant as they are sometimes claimed. A closer examination reveals that they are closer to being... engineering mistakes which other crypto currencies have copied rather blindly. More precisely we show that the capacity of current crypto currencies to resist double spending attacks is poor and most current crypto currencies are highly vulnerable. Satoshi did not implement a timestamp for bitcoin transactions and the bitcoin software does not attempt to monitor double spending events. As a result major attacks involving hundreds of millions of dollars can occur and would not even be recorded. Hundreds of millions have been invested to pay for ASIC hashing infrastructure yet insufficient attention was paid to network neutrality and to insure that the protection layer it promises is effective and cannot be abused. In this paper we develop a theory of Programmed Self-Destruction of crypto currencies. We observe that most crypto currencies have mandated abrupt and sudden transitions. These affect their hash rate and therefore their protection against double spending attacks which we do not limit the to the notion of 51% attacks which is highly misleading. In addition we show that smaller bitcoin competitors are substantially more vulnerable. In addition to small hash rate, many bitcoin competitors mandate incredibly important adjustments in miner reward. We exhibit examples of 'alt-coins' which validate our theory and for which the process of programmed decline and rapid self-destruction has clearly already started.

Hal Hodson

No abstract is available for this record.

Gihong Kim

The purpose of this paper is to analyze the characteristics of Bitcoin, focusing on the function of money. This paper includes, first of all, a comparison of various theoretical discussions made by economists on Bitcoin, defined as peer-to-peer electronic cash system. Secondly, this paper includes an analysis regarding the four unique incidents, which represent the four salient features of Bitcoin, occurred in Bitcoin’s history. The conclusion of this paper can be summarized as follows: Taking all discussions into consideration, it seems to be uncertain for Bitcoin to be regarded, at least at this moment, as new money because of its high price volatility. But, it should be emphasized that Bitcoin has played well as a medium of exchange. In spite of this uncertainty, Bitcoin’s contribution toward network money is not small at all. The most important contribution is that the technology behind Bitcoin could support a revolution the way people own and pay things. Second, Bitcoin is the first, global, single currency which can be accepted worldwide in real world as well as cyber world.

Aytek Erdil

No abstract is available for this record.

Mihail Mihaylov, Sergio Jurado, Narcís Avellana, Kristof Van Moffaert · 6 authors

In this paper we introduce a new decentralized digital currency, called NRGcoin. Prosumers in the smart grid trade locally produced renewable energy using NRGcoins, the value of which is determined on an open currency exchange market. Similar to Bitcoins, this currency offers numerous advantages over fiat currency, but unlike Bitcoins it is generated by injecting energy into the grid, rather than spending energy on computational power. In addition, we propose a novel trading paradigm for buying and selling green energy in the smart grid. Our mechanism achieves demand response by providing incentives to prosumers to balance their production and consumption out of their own self-interest. We study the advantages of our proposed currency over traditional money and environmental instruments, and explore its benefits for all parties in the smart grid.

José Eduardo Gómez-González, Julián Andrés Parra-Polanía

In the present paper we remark that the absence of an intrinsic or fundamental value represents a problem for the stability of the bitcoin’s price as an asset. In addition, we consider some …nancial stability concerns that derive from the hypothesis that the bitcoin will survive as an asset subject to high speculation.

Florian Kerschbaum, Martín Beck, Dagmar Schönfeld

Privacy is of the utmost importance in genomic matching. Therefore a number of privacy-preserving protocols have been presented using secure computation. Nevertheless, none of these protocols prevents inferences from the result. Goodrich has shown that this resulting information is sufficient for an effective attack on genome databases. In this paper we present an approach that can detect and mitigate such an attack on encrypted messages while still preserving the privacy of both parties. Note that randomization, e.g.~using differential privacy, will almost certainly destroy the utility of the matching result. We combine two known cryptographic primitives -- secure computation of the edit distance and fuzzy commitments -- in order to prevent submission of similar genome sequences. Particularly, we contribute an efficient zero-knowledge proof that the same input has been used in both primitives. We show that using our approach it is feasible to preserve privacy in genome matching and also detect and mitigate Goodrich's attack.

Nayha Acharya

Canadian courts use simple probability reasoning inconsistently in personal injury litigation, subjecting litigants to irregular legal principles and potentially improper compensation. Turning to foundational principles of tort litigation, I suggest a new framework for the availability of simple probability that would promote greater coherence. Simple probability reasoning is understood as an alternative standard of proof that enables compensation for a loss proportional to the likelihood that the loss will occur. Accordingly, the availability of simple probability is thought to depend on which types of facts (past vs. future vs. hypothetical facts) are amenable to balance of probabilities proof versus simple probability. This is the ‘type of fact’ framework, but it is not applied consistently. Part 1 argues that the inconsistency is rooted in the mischaracterization of simple probability reasoning as a standard of proof. It is better conceived of as a method of enabling chances, in their own right, to become legally relevant facts. Understood this way, simple probability is available only where chances are relevant to the legal determination at stake. I apply this characterization in Part 2, concluding that while simple probability reasoning is irrelevant to liability determinations, it is crucial in appropriately assessing damages.

Ndiamé Diop, Fitria Fitrani, Yue Man Lee, Arvind Nair · 18 authors

Within the next two decades Indonesia aspires to generate prosperity, avoid a middle-income trap and leave no one behind as it tries to catch up with high-income economies. These are ambitious goals. Realizing them requires sustained high growth and job creation, as well as reduced inequality. Can Indonesia achieve them? This report argues that the country has the potential to rise and become more prosperous and equitable. But the risk of 'floating in the middle' is real. Which pathway the economy will take depends on: (i) the adoption of a growth strategy that unleashes the productivity potential of the economy; and (ii) consistent implementation of a few, long-standing, high-priority structural reforms to boost growth and share prosperity more widely. Indonesia is fortunate to have options in financing these reforms without threatening its long-term fiscal outlook. The difficulties lie in getting the reforms implemented in a complex institutional and decentralized framework. But Indonesia cannot afford hard to not try harder. The costs of complacency, and the rewards for action, are too high.

Xiaobo Lü

Elites often use social policies to garner political support and ensure regime survival, but social policies are not a silver bullet. Using two waves of Chinese national surveys, I find that a recent policy of abolishing school fees has significantly increased citizens’ demand for greater government responsibility in financing compulsory education. I argue that policy awareness, rather than policy benefits, drives citizens’ demand. Finally, I show that policy awareness has enhanced citizens’ trust in China's central government, but not in local governments. This asymmetry in regime support has two sources—the decentralization of education provision and biased media reporting—which induce citizens to credit the central government for good policy outcomes. Given that citizens’ responses are primarily influenced by policy awareness that is promoted by the state media, this study casts doubt on the use of social policies to sustain long-term political support.

John Nix

[Associate Editor's note: In the September 2008 edition of Voice Research and Technology, I introduced a topic called Quantifying Tessitura in a Song. It was more of a teaser than a complete work. My good friend John Nix completed a real study, including dosimetry on a singer who performed a Mozart composition (different from Il mio tesoro intanto, which I used for my test case)-Ingo R. Titze.]INTRODUCTIONSelecting appropriate repertoire is a primary responsibility for a singing teacher. Astute repertoire selection can help address the technical and musical development of a singer, as well as advance a singer's career in the case of those who are working professionals. Traditionally, repertoire is assigned on an individual basis by carefully considering the singer's age, gender, technical challenges, personality, musicianship, and developmental level, then cross referencing that singer assessment with an evaluation of the vocal, musical, linguistic, and expressive challenges of potential repertoire.1 A number of print2 and web3 resources exist to assist teachers in choosing potential new literature.In the past, the selection process has depended upon the acquired ability of the singing teacher both to evaluate his or her students and to make judgments about vocal repertoire based upon personal knowledge and close examination of the literature. In recent years, however, the voice range profile (VRP) and voice dosimetry have begun to show promise as objective tools that could assist teachers with the selection process.Several articles have suggested ways in which the VRP could be used or improved upon for determining the voice classification of performers or for guiding repertoire choices. Emerich, Titze, Svec, Popolo, and Logan compared laboratory VRPs for eight professional actors with speech range profiles of the actors during a dramatic scene recorded in a laboratory and on stage in performance.4 At times, the actors exceeded their VRP thresholds when in either of the performance conditions. The study highlighted both the utility of the VRP when comparing laboratory values with actual performance voice usage and the shortcomings of the VRP in predicting what repertoire might exceed a performer's capabilities given the emotional content of live performance. Lamarche, Ternstrom, and Hertegârd also looked at the VRP as compared to the performance of repertoire, combining a commercial VRP program with a response button that subjects pressed during moments of difficult production.5 The subjects, all female professionally trained singers, performed three tasks, including the singing of their best aria, using performance-acceptable quality. Subjects also rated how well the button pressings reflected their experiences and usual vocal challenges; this rating included a viewing of a visual graph of the button responses. The investigators' coupling of objective data from the VRP tasks with (a) the singer's self-assessment captured mid-task and (b) the postperformance evaluation of the data and the responses shows significant promise as a means for enhancing singing teachers' guidance of their students. Lamarche, Ternstrom, and Pabon continued testing improvements of the VRP for singers by examining whether VRPs for singers should be limited to physiological measures (without considering performance quality elements), or whether performance abilities should also be measured in some fashion.6 After testing thirty female subjects, all professionally active singers, they concluded that examining the voice as it is used in performance has clinical importance, and that both types of VRPs should be used for assessing singers. Finally, Herbst, Duus, Jers, and Svec compared the maximum phonation frequency range (MPFR) of amateur choir singers (as gathered during a VRP) with the required pitch range (RPR) for their chosen voice part within a choir, based upon part ranges specified in a commonly used music reference. …

Antonella Nocco, Gianmarco I.P. Ottaviano, Matteo Salto

We provide novel insights on the decentralization of optimal outcomes under monopolistic competition with nonseparable utility, variable demand elasticity, and endogenous firm heterogeneity. Relative to the unconstrained optimum, equilibrium firm selection is too weak, average firm size is too small, low-cost firms are too small, and high-cost firms are too large. The unconstrained optimum can be decentralized through differentiated production subsidies to producers financed through lump-sum taxes on entrants and consumers. When differentiated subsidies and transfers from entrants are not viable, the constrained optimum can be decentralized through a common production subsidy financed by a lump-sum tax on consumers.

Nesrine Kaaniche, Ethmane El Moustaine, Maryline Laurent

Recent technological advances have given rise to the popularity and success of cloud storage. However, the prospect of outsourcing an increasing amount of data to a third party and the abstract nature of the cloud foster the proliferation of security and privacy challenges, namely, the remote data possession checking. This paper addresses this critical security concern, when storing sensitive data in a cloud storage service, and the need for users to trust commercial cloud providers. It proposes a deterministic Proof of Data Possession (PDP) scheme based on Interactive Proof System(IPS) and an original usage of the GPS scheme. Our approach has several advantages. First, it supports public verifiability which releases data owners from the burden of a periodical verification. Second, it provides constant communication complexity, where the exchanged messages between the storage server and the client are composed of constant number of group elements. Third, our solution is efficient and provably secure, as it is resistant to the fraudulence of the prover and the leakage of verified data.