Blockchain Papers

Maria Cristina Ștefan, Constanța Popescu, Corneliu Ştefan

No abstract is available for this record.

Liu Guang-jun

China's fiscal decentralization reform has gone through a strange process of unitive-segregative-unitive,it has had been institutionalized starting from the 1980s,Although the whole fiscal reform is a gradual process,the tax sharing reform in 1994 implemented by the central government is distinctively different from former reforms such as fiscal sharing and fiscal contracting,the boundary is fixed in finance power and finance affair.As viewed from the institutional transition of fiscal decentralization,there are many problems:central authority and local authority can game constantly,obvious path-dependence in institutional transition;randomness and order is reversed in decentralization;the contradiction between fiscal decentralization and administration centralization of state power;transfer payment do not standardize and so on.Therefore,the system of fiscal decentralization should be innovative from many aspects in china.

Clément Carbonnier

This article presents a model of optimal decentralization of economic governance. It focuses on the provision of public input for private production. It considers that the decision power is given to a local government if it has the full right to decide new investments and new taxes to finance it. Three economic forces act on this optimal decentralization of the decision. First is the centripetal force which consists in the increasing accuracy and relevance of public investments when decided more locally. The second and third are the centrifugal forces of the administrative costs on the one hand and of the fiscal competition among decentralized jurisdictions on the other. Formal proofs of the existence and uniqueness of solutions are given under special hypotheses and in general. Numerical analysis is also done to understand the impact on the optimal decentralization level of the different model parameters.

Veronika Eretová

The thesis "The use of maps to depict real estate tax coefficient" deals with maps as an alternative instrument of depicting data and information. Its objective is to demonstrate maps as a possible and appropriate tool to present information on management of municipalities. At first, the thesis is focused on creation of maps and their advantages of the depiction of information. The second part of the thesis deals with the importance of decentralization of government and the sense of municipalities. The thesis also debates income of municipalities, especially the real estate tax and its local coefficient, which is an important component of financial independence of municipalities. The thesis also examines the influence of depicting information in maps on the transparency of public finance. Finally, the use of maps is presented on two examples -- depiction of municipalities applying local real estate tax coefficient and testing the theory of yard stick competition by depicting information of neighbouring municipalities applying local real estate tax coefficient.

Harry Kalodner, Miles Carlsten, Paul Ellenbogen, Joseph Bonneau · 5 authors

Secure decentralized namespaces have recently become possible due to cryptocurrency technology. They enable a censorship-resistant domainname system outside the control of any single entity, among other applications. Namecoin, a fork of Bitcoin, is the most prominent example. We initiate the study of decentralized namespaces and the market for names in such systems. Our extensive empirical analysis of Namecoin reveals a system in disrepair. Indeed, our methodology for detecting “squatted” and otherwise inactive domains reveals that among Namecoin’s roughly 120,000 registered domain names, a mere 28 are not squatted and have nontrivial content. Further, we develop techniques for detecting transfers of domains in the Namecoin block chain and provide evidence that the market for domains is thin-tononexistent. We argue that the state of the art in mechanism design for decentralized namespace markets is lacking. We propose a model of utility of different names to different participants, and articulate desiderata of a decentralized namespace in terms of this utility function. We use this model to explore the design space of mechanisms and analyze the trade-offs.

Mohammad Sadeq Dousti, Rasool Jalili

Abstract—Many cryptographic primitives, such as pseudorandom generators, encryption schemes, and zero-knowledge proofs, center around the notion of approximability. For instance, a pseudorandom generator is an expanding function which on a random seed, approximates the uniform distribution. In this paper, we classify different notions of computational approximability in the literature, and provide several new types of approximability. More specifically, we identify two hierarchies of computational approximability: The first hierarchy ranges from strong approximability—which is the most common type in the cryptography—to the weak approximability—as defined by Dwork et al. (FOCS 1999). We define semi-strong, mild, and semi-weak types as well. The second hierarchy, termed K-approximability, is inspired by the ε-approximability of Dwork et al. (STOC 1998). K-approximability has the same levels as the first hierarchy, ranging from strong K-approximability to weak K-approximability. While both hierarchies are general and can be used to define various cryptographic constructs with different levels of security, they are best illustrated in the context of zero-knowledge protocols. Assuming the existence of (trapdoor) one-way permutations, and exploiting the random oracle model, we present a separation between two definitions of zero knowledge: one based on strong K-approximability, and the other based on semi-strong K-approximability. Especially, we present a protocol which is zero knowledge only in the latter sense. The protocol is interesting in its own right, and can be used for efficient identification. Next, we show that our model for zero knowledge was not closed under sequential composition, and change the model to resolve this issue. After proving a composition theorem, we finally provide a version of the identification protocol which satisfies the requirements of the new model. Some techniques provided in this paper are of independent interest, such as proving a composition theorem in the presence of both simulator and knowledge extractor.

Bao Li

A generic way to construct a deniable group key establishment protocol from an unauthenticated group key es-tablishment protocol was proposed.The construction could be seen as a compiler.By using Schnorr's zero-knowledge identification scheme,this compiler could transform an unauthenticated group key establishment to a deniable group key establishment protocol with only additional two round communications and one round verification.It is very efficient and practical.The security and deniability proof is in the Random Oracle model.A concrete transforming example of the con-struction was also presented.

Ka-Ho Mok, Xiaozhou Xu

The economic transition in China since the late 1970s has led to not only drastic social transformations but also rapid advancements in science and technology, as well as the revolution in information and communications technology. In order to enhance the global competence of the Chinese population in coping with the challenges of the knowledge-based economy, the higher education sector has been going through restructuring along the lines of marketization, privatization, and decentralization. Responding to the globalization challenges, the Chinese government has opened up the education market by allowing private/ minban higher education institutions and even overseas universities to offer academic programs in the mainland. Hence, we have witnessed the proliferation of education providers, the diversification of education financing, and the increase in private—public partnership in education provision since the policy of educational decentralization was introduced in the mid-1980s. After China’s accession to the World Trade Organization (WTO), the Chinese government has allowed overseas universities in collaboration with local universities to co-launch higher education programs. In this policy context, we set out in this chapter to examine the current developments of transnational higher education in China. More specifically, we focus on how students in Zhejiang province enrolling in these overseas programs evaluate their learning experiences. We also identify and discuss major issues arising from the onset of transnational education in China. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Patrizia Battilani

Numerous studies have been made of regional differences in income and level of development in Italy, and these studies basically differ in the responses they give to the question of whether the said differences were already of a substantial nature prior to Unification, or whether in fact they have widened since then. The present essay is going to examine this problem by focusing on the local administrative system adopted after Italian Unification, in order to ascertain the existence of a different approach to public intervention at the local level, and thus to the existence of disparities in local public spending. The paper offers an analysis of the actual working of the post-Unification administrative system in Italy, in terms both of the powers attributed to Italy’s municipalities and provinces, and of the degree of autonomy they had in deciding on funding methods. This analysis aims to ascertain whether the chosen strategy could have been maintained in a state characterized by strong regional differences, and to establish the kind of impact such a strategy had on the regional differences themselves. The main conclusion is that in absence of any sort of automatic transfer from the more industrialized regions to the poor ones, the adoption of a decentralized tax system for the financing of local public expenditure contributed to the deepening of regional divide. As a consequence at the beginning of the 19th century the central government started to subsidize the poorest regions and little by little move towards a more centralized fiscal system.

Marina Zaharioaie, Irina Bosie

Development of public services is the effect of applying administrative reforms involving the banks and financial contribution. Decentralization strengthening and modernization of administrative structures and public services is supported by the World Bank, International Monetary Fund and the European Union, supplement the financial resources to facilitate development. To attract financing funds, local governments often resort to loans from the banks that manage the funds targeted. Money is used to supplement the income of local governments who needs loans for financing European projects. Empirical research on this way will make disclosures regarding the various types of banks involved in this process.

Vivek Reddy Sama

Cryptographic protocols that are established as secure in the Universally Composable (UC) model of security provide strong security assurances even when run in complex environments. Unfortunately, in order to achieve such strong security properties, UC protocols are often impractical, and most non-trivial two-party protocols cannot be secure in the UC model without some sort of external capability (or setup assumption) being introduced. Recent work by Hofheinz et al provided an important breakthrough in designing realistic universally composable two party protocols, in which they use trusted, tamper proof hardware as a special type of helping functionality which they call a catalyst. Hofheinz et al. use government issued signature cards as a catalyst to design universally composable protocols for zero-knowledge proofs and commitments, but did not give a complete security proof for either protocol. In this thesis, we consider another form of security hardware, Trusted Platform Modules (TPMs), which are more widespread than signature cards and are currently shipped as a part of almost every business laptop or desktop. Trusted Module Platforms are tamper evident devices which support cryptographic functionalities including digital signatures, but have a different key management model from signature cards. In this thesis we consider TPMs as catalysts and describe a universally composable zero knowledge protocol using Trusted Platform Modules. We also present a complete security proof for both the Hofheinz's universally composable zero knowledge protocol from signature cards and our universally composable zero knowledge protocol using TPMs as a catalyst.

Zhenfu Cao, Zongyang Zhang, Yunlei Zhao

A zero-knowledge protocol allows a prover to convince a verifier of the correctness of a statement without disclosing any other information to the verifier. It is a basic tool and widely used in many other cryptographic applications. However, when stand-alone zero-knowledge protocols are used in complex environments, e.g., the Internet, the basic properties may not be sufficient. This is why researchers considered security of zero-knowledge protocols under concurrent composition and manin-the-middle attacks. Moreover, it is very likely that an adversary might break computers that run the protocol and get internal information of the parties. It is thus necessary to take account of the security of zero-knowledge protocols when adaptive corruptions are allowed. Previous adaptively secure zero-knowledge protocols work either in a stand-alone setting, or in a concurrent setting with trusted setup assumptions. In this paper, we study adaptive security of zero-knowledge protocols under both concurrent self composition and man-in-the-middle attacks in the plain model (i.e., without any set-up assumptions). We provide a construction of adaptively secure concurrent non-malleable zero-knowledge proof/argument for every language in NP.

Víctor Becerril‐Montekio, Guadalupe Medina, Rosana Aquino

This paper describes the Brazilian health system, which includes a public sector covering almost 75% of the population and an expanding private sector offering health services to the rest of the population. The public sector is organized around the Sistema Unico de Saude (SUS) and it is financed with general taxes and social contributions collected by the three levels of government (federal, state and municipal). SUS provides health care through a decentralized network of clinics, hospitals and other establishments, as well as through contracts with private providers. SUS is also responsible for the coordination of the public sector. The private sector includes a system of insurance schemes known as Supplementary Health which is financed by employers and/or households: group medicine (companies and households), medical cooperatives, the so called Self-Administered Plans (companies) and individual insurance plans. The private sector also includes clinics, hospitals and laboratories offering services on out-of-pocket basis mostly used by the high-income population. This paper also describes the resources of the system, the stewardship activities developed by the Ministry of Health and other actors, and the most recent policy innovations implemented in Brazil, including the programs saude da Familia and Mais Saude.

Elena A. Blagorodova

<p>Successful cultural politics in Russia may be carried out on the basis of its management decentralization principle. Regional and municipal culture development is not possible without common national cultural aims and priorities. The state should play an essential role, however<br />regional cultures should be given self-development possibilities. Culture management decentralization should not get reduced to the financing issues. Decentralization priority aim should be improvement in efficiency of both cultural organizations and governmental authorities of the<br />federal and local levels.</p>

Ronald Cramer

No abstract is available for this record.

Zeev Dvir, Dan Gutfreund, Guy N. Rothblum, Salil Vadhan

Abstract: We investigate the complexity of the following computational problem: Polynomial Entropy Approximation (PEA): Given a low-degree polynomial mapping p: Fn → Fm, where F is a finite field, approximate the output entropy H(p(Un)), where Un is the uniform distribution on Fn and H may be any of several entropy measures. We show: • Approximating the Shannon entropy of degree 3 polynomials p: Fn 2 → Fm 2 over F2 to within an additive constant (or even n.9) is complete for SZKPL, the class of problems having statistical zero-knowledge proofs where the honest verifier and its simulator are computable in logarithmic space. (SZKPL contains most of the natural problems known to be in the full class SZKP.) • For prime fields F = F2 and homogeneous quadratic polynomials p: Fn → Fm, there is a probabilistic polynomial-time algorithm that distinguishes the case that p(Un) has entropy smaller than k from the case that p(Un) has min-entropy (or even Renyi entropy) greater than (2 + o(1))k. • For degree d polynomials p: Fn 2 → Fm 2, there is a polynomial-time algorithm that distinguishes the case that p(Un) has max-entropy smaller than k (where the max-entropy of a random variable is the logarithm of its support size) from the case that p(Un) has max-entropy at least (1 + o(1)) · kd (for fixed d and large k).

Sehzada Salihbasic

The functions of the health system, according to the key objectives and relationships within the sub-systems that are available to the policy makers and managers in the Health Care system in Bosnia and Herzegovina - B&H, have been elaborated in detail, with the analytical overview of relevant indicators, thus confirming the limitations of the health promotion in B&H. The ability to overcome the expressed problems is in the startup of process for structural adjustment of the health sector, reform of the health care system and its financing. The reform in health system implies fundamental changes that need to take place, in B&H, as a state in health policy and institutions in the health care system, in order to improve the functioning of health systems with the aim of ensuring better health of the population. Reform implies the existence of documents with clearly formulated health policy objectives, for which the state stands, and for which a consensus was reached on the national level with all key actors in the political structure: public promotion of the basic principles for carrying out the reform, its implementation within a reasonable time frame, the corresponding effects for providers and customer satisfaction, as well as improving health services' efficacy (i.e. micro and macro) and the quality of healthcare. In this article, we elaborated the criteria for the classification of health systems, whereby the scientifically-based and empirical analysis is conducted on the health system in B&H and elaborated the key levers of the system. Leveraged organizational arrangements relating to the economic and political environment, organization and management functions, in connection with the services of finance, funds, customers and service providers, from which it follows the framework of state legislation related to health policy and health institutions at the state level are responsible for finance, planning, the organization, payment, regulation and conduct. If we start from the administrative criteria for the classification of "health sub-systems" in B&H, it is difficult to fit them in a pluralistic, decentralized or monistic, because in the system for each organization, there should be health policy at the state level, which is in the most countries represents the Ministry of Health.

Jeff Naruchitparames, Mehmet Hadi Gunes, Cansın Yaman Evrenosoglu

This paper focuses on deployment of smart meters in the power distribution systems to enhance the operation infrastructure. An important challenge in establishing a communication paradigm between the utilities and the customers is that customers are susceptible to privacy concerns. In this paper, we present a model to ensure the privacy and integrity of communicating parties within the smart grid by using smart meters as a gateway between intra- and inter-network communications. In particular, we utilize the smart meter as a firewall to manage incoming and outgoing traffic and mediate household devices based on the instructions from the electric utility. Moreover, third parties are introduced in our model such as service providers so that they can monitor and manage the contracted customers by using the existing communication infrastructure.

Inger K. Holmström

No abstract is available for this record.

Zheng Fang

This empirical study found that there is a significant impact between several corporate internal governance mechanisms,such as equity balance,the proportion of independent directors and the transparency of information and the cost of equity financing for listed companies in China,while for state-owned listed companies,the separation of chairman and CEO and board size are significant factors.Because of the awakening of self-protection of investors,more attention began to be paid to restrict the behavior of large shareholders through the shareholder governance mechanisms;Meanwhile,investors tend to use the means of decentralization,taking into account the actual situation in China.

Lise Debout

The collection of household waste is the only sector that is the full responsibility of municipalities in Jordan. Lise Debout gives a highly original analysis, dealing with the emergence of public-private partnerships and the role of NGOs and private contractors. The author explains that the public service of collecting household waste is an element of the relationship between citizens and government, then she describes the scope of the Jordanian government in the process of privatization and decentralization of this little-studied sector, which leads her to address the issue of state sovereignty. With 255kg to 310kg per capita per year, or about 1.46 million tons per year, the amount of waste produced in Jordan is higher than the average in low-income countries, by virtue of its high rate of urbanization, but 56% of this waste is organic. Under the 1955 Municipalities Act, the collection of household waste is the responsibility of municipalities, along with the financing thereof. It is the only public utility that is their full responsibility. The service is managed by the Department of the Environment and Public Health within municipalities. However, there is a conflict with the new Ministry of the Environment.Institutional reforms have been limited lest they undermine national stability. Thus the autonomy of municipalities is a risk factor for the Jordanian government, as shown by the amalgamation reforms which provided for the autonomy of senior municipalities, but which has not been implemented in Irbid or Zarqa. This is also why programs of municipal development and decentralization are doomed to failure. The Jordanian State wishes to maintain its sovereignty while its people are reluctant to accept privatization measures which are seen as interference by foreign powers.

Brijesh Mainali

The availability of abundant renewable resources, lack of fossil fuels and difficult geographical terrain for grid line extensions contribute to the advantages of renewable based decentralized rural electrification in Ne-pal. Solar home system (SHS) and micro-hydro are the most commonly adopted off-grid renewable energy technologies in the country. This dis-sertation examines the market of renewable energy based rural electrifi-cation within prevailing policy and programmes framework. The study verifies whether the market has been able to serve the poor in Nepal. It also captures the perception of various stakeholders (e.g. private sup-ply/installation companies, NGOs, financial institutions and the donor‘s programme) regarding the business, financing issues and the role of gov-ernment policy on the market development. In addition, the study dis-cusses and analyses renewable based rural electrification supply models, the economics behind rural electrification, market drivers and market distribution in the rural areas of Nepal. The financial mix in the off-grid rural electrification is generally charac-terized by subsidy, equity and credit. The study shows that awareness about renewable energy technologies and willingness to pay for electricity access has increased considerably. However, there is a huge financial gap between the cost of electrification and affordability among the poor. The distribution analysis shows there is significant increment in the extensive growth but decrease in the intensive growth rate of rural electrification thus indicating market expansion with uneven penetration among the ru-ral people. Solar PV technology is still not in the reach of the economic poor. Access to credit and cumbersome subsidy delivery mechanisms have been perceived as the major factors affecting the expansion of rural electrification by the stakeholders, requiring innovation in the credit and subsidy delivery system so that a larger rural population can be given ac-cess to electrification.

Marcela Cristini, Ramiro Moya, Guillermo Bermúdez

In the last three decades, the supply of housing in Argentina has not kept pace with demand. This study analyzes the main drivers of Argentina's housing market and relates them to the macroeconomic environment in order to advance a policy agenda for housing policy reform. The demand for housing was calculated and tenure choice was analyzed. Structural characteristics affecting Argentina's housing market include the high concentration of the urban population in a few large metropolitan areas, te association of urban poverty with the housing deficit, and overcrowding. The mortgage market lost its appeal following the 2001-02 crisis due to widespread breaches of contract legitimized through protective legislation (still in place), insufficient long-term financing, and high inflation. The housing deficit could be eliminated in five to eight years if well-coordinated policy initiatives to develop the mortgage market and provide low-income housing were adopted under a decentralized, demand-driven, subsidized program.

T Yugang, Ye Chenghao

This paper explores the mechanism of China's tax growth within a framework of intergovernmental competition.Tax Competition takes place through endogenous tax collecting efficiency.Horizontal competition tends to lower the effective equilibrium tax rate,while vertical competition has the reverse effect.Since the 1993 tax reform,concentration of tax revenue to upper-level governments and regulation of local public finance imposed by the central government,have led to stronger vertical effects and relatively weaker horizontal effects.The paper offers us not only a new perspective to understand China's fiscal decentralization,but also an efficiency principle to design optimal tax sharing system.