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. With two pools, or any number of identical pools, there exists an equilibrium that constitutes a tragedy of the commons where the pools attack one another and all 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.
Marc Solanas, Julio Hernandez-Castro, Debojyoti Dutta
More users and companies make use of cloud services every day. They all expect a perfect performance and any issue to remain transparent to them. This last statement is very challenging to perform. A user's activities in our cloud can affect the overall performance of our servers, having an impact on other resources. We can consider these kind of activities as fraudulent. They can be either illegal activities, such as launching a DDoS attack or just activities which are undesired by the cloud provider, such as Bitcoin mining, which uses substantial power, reduces the life of the hardware and can possibly slow down other user's activities. This article discusses a method to detect such activities by using non-intrusive, privacy-friendly data: billing data. We use OpenStack as an example with data provided by Telemetry, the component in charge of measuring resource usage for billing purposes. Results will be shown proving the efficiency of this method and ways to improve it will be provided as well as its advantages and disadvantages.
Marazaenal Adipta, M.Pd . Made Artana, M.Pd. . Anjuman Zukhri
Penelitian ini bertujuan untuk mengetahui (1) pelaksanaan otonomi daerah di Kabupaten Lombok Tengah Nusa Tenggara Barat (NTB) tahun 2010-2013, (2) kemampuan keuangan daerah dalam pelaksanaan otonomi daerah di Kabupaten Lombok Tengah Nusa Tenggara Barat (NTB) tahun 2010-2013, dan (3) konstribusi Pendapatan Asli Daerah terhadap Anggaran Pendapatan dan Belanja Daerah tahun 2010-2013 dalam menunjang pelaksanaan Otonomi Daerah di Kabupaten Lombok Tengah. Penelitian ini merupakan penelitian deskriptif kualitatif dan kuantitatif. Data dikumpulkan dengan metode dokumentasi dan wawancara yang dianalisis menggunakan rasio keuangan daerah. Hasil penelitian menunjukkan bahwa (1) Pelaksanaan otonomi daerah di Kabupaten Lombok Tengah NTB tahun 2010-2013 dijalankan sesuai dengan peraturan yang berlaku dan disesuaikan dengan kondisi real masyarakat. (2) Kemampuan keuangan daerah dalam pelaksanaan otonomi daerah di Kabupaten Lombok Tengah Nusa Tenggara Barat (NTB) tahun 2010-2013 rata-rata berada dalam katagori yang kecil sehingga dapat dikatakan Kabupaten Lombok Tengah belum mampu untuk melaksanakan otonomi daerah jika dilihat dari kemampuan keuangan daerah, dari hasil perhitungan rasio keuangan daerah antara lain rasio kemandirian keuangan daerah, rasio derajat desentralisasi fiskal, rasio indeks kemampuan rutin, rasio keserasian, dan rasio pertumbuhan, hanya rasio pertumbuhan yang menggambarkan Kabupaten Lombok Tengah sedikit mampu dalam menjalankan otonomi daerah, dan (3) Kontribusi Pendapatan Asli Daerah terhadap Anggaran Pendapatan dan Belanja Daerah tahun 2010-2013 dalam menunjang pelaksanaan otonomi daerah di Kabupaten Lombok Tengah masih kecil.
Kata Kunci : pelaksanaan otonomi daerah, kemampuan keuangan daerah, PAD This study aims to determine (1) the implementation of regional autonomy in Central Lombok West Nusa Tenggara (NTB) 2010-2013, (2) the ability of local finance in the implementation of regional autonomy in Central Lombok West Nusa Tenggara (NTB) 2010-2013 , and (3) the contribution of the Local Revenue and Expenditure Budget 2010-2013 in supporting the implementation of regional autonomy in Central Lombok. This research is descriptive qualitative and quantitative. Data collected by the method of documentation and interviews were analyzed using financial ratios area. The results showed that (1) The implementation of regional autonomy in Central Lombok NTB 2010-2013 carried out in accordance with the applicable rules and adapted to the real conditions of society. (2) the financial ability of the region in the implementation of regional autonomy in Central Lombok West Nusa Tenggara (NTB) 2010-2013 average are in the category of small so it can be said of Central Lombok district has not been able to implement regional autonomy when viewed from the local financial capacity , from the calculation of financial ratios among other areas of local financial independence ratio, the ratio of the degree of fiscal decentralization, routine capability index ratio, the ratio of harmony, and the ratio of growth, the growth rate only describe Central Lombok bit capable in carrying out regional autonomy, and (3) Contributions to the local Revenue and Expenditure Budget 2010-2013 year in supporting the implementation of regional autonomy in Central Lombok is still small.
Kata Kunci : pelaksanaan otonomi daerah, kemampuan keuangan daerah, PAD This study aims to determine (1) the implementation of regional autonomy in Central Lombok West Nusa Tenggara (NTB) 2010-2013, (2) the ability of local finance in the implementation of regional autonomy in Central Lombok West Nusa Tenggara (NTB) 2010-2013 , and (3) the contribution of the Local Revenue and Expenditure Budget 2010-2013 in supporting the implementation of regional autonomy in Central Lombok. This research is descriptive qualitative and quantitative. Data collected by the method of documentation and interviews were analyzed using financial ratios area. The results showed that (1) The implementation of regional autonomy in Central Lombok NTB 2010-2013 carried out in accordance with the applicable rules and adapted to the real conditions of society. (2) the financial ability of the region in the implementation of regional autonomy in Central Lombok West Nusa Tenggara (NTB) 2010-2013 average are in the category of small so it can be said of Central Lombok district has not been able to implement regional autonomy when viewed from the local financial capacity , from the calculation of financial ratios among other areas of local financial independence ratio, the ratio of the degree of fiscal decentralization, routine capability index ratio, the ratio of harmony, and the ratio of growth, the growth rate only describe Central Lombok bit capable in carrying out regional autonomy, and (3) Contributions to the local Revenue and Expenditure Budget 2010-2013 year in supporting the implementation of regional autonomy in Central Lombok is still small.
keyword : the implementation of regional autonomy, local financial capacity, PAD
keyword : the implementation of regional autonomy, local financial capacity, PAD
Enas Al Kawasmi, Edin ArnautoviÄ, Davor SvetinoviÄ
ABSTRACT This paper presents a systemâofâsystems architecture model for a Decentralized Carbon Emissions Trading Infrastructure (DâCETI) with focus on privacy and system security goals. The structure and behavior are implemented as a solution to the problem of trading carbon emissions anonymously among the trading agents. Privacy and security of the trading agents and their carbon credits are the main requirements behind the architecture of DâCETI. The decentralized structure of multiple systems and distributed behavior are the two main features of DâCETI that distinguish it from the traditional carbon trading schemes and protocols. DâCETI is based on Bitcoin, a peerâtoâpeer digital currency with no central authority, and Open Transactions, a system that simplifies the use of cryptography in financial transactions. The architecture of DâCETI is evaluated and compared with the architecture of five other carbon emissions trading platforms.
Decentralization in the country has been developing gradually over the last 20 years. These changes in the way public administration make the study of public finance, distribution and use of resources is a source of knowledge of the actual reality of the departments and municipalities. The breaking point between centralization and decentralization is the enactment of the Constitution of 91. Subsequent legislation sought a controlled decentralization of resources transferred from the nation to the territories. This is where the General System of Units hard to regulate the use and form of distribution of transfers. These scarce resources should be used to respond to unmet basic needs of citizens. When these demands are not answered effectively ungovernable problems experienced by the country's poorest municipalities are generated.
In order to increase the utilization of renewable energy sources and to reduce the need of generator-provided ancillary services and inefficient peaking generation, buildings are progressively transforming into smarter electricity consumers and active participants in power system operations. In this work, an R-C thermodynamic model of building that strongly relates to the power consumption of heating ventilation air-conditioning system (HVAC) is firstly introduced. To offer the aggregated flexible HVAC power to the grid as regulating power, we propose a building-aggregator-grid contract framework and formulate a robust model predictive control (MPC) algorithm which both maximizes the profit of aggregator and minimizes the payment of each participating building to optimally declare power flexibility. Lastly, simulation results on a group of real and hypothetical buildings validate the feasibility of the proposed method.
Financing Agreement (Additional Financing for the Second Decentralized City Management Project) between the Republic of Benin and the International Development Association (with schedules, appendix and International Development Association General Conditions for Credits and Grants, dated 1 July 2005, as amended through 15 October 2006). Cotonou, 12 September 2008
A major challenge for investment treaty designers and adjudicators is to separate opportunistic behavior by host states that should be sanctioned under international law from bona fide public policy measures that should not. This article suggests that international investment agreements ( iia s) need to be both âsmarterâ and more âflexibleâ to better make that distinction. It draws on economic contract theory as a basic framework, and political economy theory for fine-tuning.
The rationale for considering decentralization in anti-poverty programs is that it might have positive effects on the economic development. Decentralization brings the government closer to the people. Local officials are better informed on the local needs, and are thus more capable of providing the optimal mix of local policies. While the SMEs subsector constitute close to 80% of employment, it only contributes to about twenty percent (20%) of the Gross Domestic Product (GDP) in 2011 in Kenya. This implies dismal subsector performance despite its potential contribution to employment, income and equity as was asserted in the ILO report in 1972. The performance of the SMEs in Kenya is linked to several constraints among which the regulatory and institutional framework is alleged to be one of the factors. SMEs in Kenya are threatened for survival as a competitive enterprise. The purpose of the study was to establish the effect of devolution on small and medium enterprises performance in Kenya. The study adopted a descriptive survey research design. The target population of this study composed of representatives of the various industries including the matatu, dairy, supermarkets, jua kali and small manufacturing companies in Nairobi and its environs. The target population of this study was therefore 1015. The study used stratified random sampling method to select 10% of the respondents who formed a sampling frame of 102 respondents. Data was collected using questionnaires. Data was analyzed using descriptive statistics done with the help of software program SPSS version 21 and presented using frequency tables. In addition, multivariate regression model was applied to determine the relative importance of each of the two variables with respect to SME performance. The study revealed that that fees and levies, affect the performance of Small and Medium Enterprises in Kenya to a moderate extent. The study concluded that fees and levies, cess and rates by the county government affect the performance of Small and Medium Enterprises in Kenya. The study also concluded that SME financing mechanism, fair trading practices, capacity development, mechanism for value addition and increase in supply, distribution and access to goods and services affect the performance of Small and Medium Enterprises affect the performance of SMEs in Kenya. The recommends that the county government should use the finances collected from fees and levies, cess and rates in proper and controlled manner with a goal of improving the working environment for the SMEs in Kenya. The study also recommends that the county government should put in strict measures to ensure that there is no corruption in the fees and levies, cess and rates collection process to ensure that the amount collected do not go to the hands of few individuals and that a substantial amount can be received to support the plans and policies of the county government. The study suggested that a similar study should be carried out in other counties to find out whether it will yield the same results. The study focused on SMEs, another study should be carried out to find out the effect of devolution on large companies.
We show that the behaviour of Bitcoin has interesting similarities to stock\nand precious metal markets, such as gold and silver. We report that whilst\nLitecoin, the second largest cryptocurrency, closely follows Bitcoin's\nbehaviour, it does not show all the reported properties of Bitcoin. Agreements\nbetween apparently disparate complexity measures have been found, and it is\nshown that statistical, information-theoretic, algorithmic and fractal measures\nhave different but interesting capabilities of clustering families of markets\nby type. The report is particularly interesting because of the range and novel\nuse of some measures of complexity to characterize price behaviour, because of\nthe IRS designation of Bitcoin as an investment property and not a currency,\nand the announcement of the Canadian government's own electronic currency\nMintChip.\n
Digital signature schemes are a foundational cryptographic building block in certification and the projection of trust. Based on a signature scheme on committed graphs, we propose a framework of certification and proof methods to sign topology graphs and to prove properties of their certificates in zero-knowledge. This framework allows an issuer, such as an auditing system, to sign the topology representation of an infrastructure. The prover, such as an infrastructure provider, can then convince a verifier of topology properties including connectivity and isolation without disclosing the blueprint of the topology itself. By that, we can certify the structure of critical systems while still maintaining confidentiality. We offer zero-knowledge proofs of knowledge for a general specification language of security goals for virtualized infrastructures such that high-level security goals can be proven over topology certificates. We offer an efficient and practical construction, built upon the Camenisch-Lysyanskaya signature scheme, honest-verifier proofs and the strong RSA assumption.
This paper explores the recent development of digital currenciesâcurrencies which are creatures of the Internet, self-authenticating, and usable worldwide by members of the general public to engage in the same types of direct, one-to-one transactions that daily occur using government-issued currencies. At present, the most developed digital currency measured by market capitalization is Bitcoin, which will be used as a proxy for the general phenomenon. Not surprisingly, as Bitcoinâs circulation and visibility has increased, so have the number of practical and legal issues surrounding its use. Some of these will be explored in this paper, with a view to considering the utility and viability of such currencies for widespread, global use.
Beim Bitcoin handelt es sich um eine dezentrale virtuelle Wahrung in einem Peer-to-Peer Netzwerk. Die digitalen Munzen wurden 2008 durch Satoshi Nakamoto erfunden und seit 2009 in Umlauf gebracht. Das angestrebte Ziel des Bitcoin sind Transaktionen zum Erwerb virtueller und realer Guter ohne das Einwirken von Finanzintermediaren. Dadurch konnen Transaktionskosten minimiert werden. Das Vertrauen in solche dritte Parteien wird dabei durch ein mathematisches Konzept ersetzt und durch das Bitcoinnetzwerk und all seine Nutzer sichergestellt. Obwohl die digitalen Munzen eigentlich als Tauschmittel konzipiert wurden, ist der aktuelle Anwendungsbereich noch sehr gering. Die Kursentwicklung hingegen erfuhr seit Anfang 2013 mehrere Berg- und Talfahrten auf den Handelsplattformen fur den Bitcoin. Wahrend sich viele wissenschaftliche Arbeiten mit den technischen Aspekten im Bereich der Informatik befassen, klafft im okonomischen Kontext noch eine grose Lucke. Was macht ein Zahlungsmittel eigentlich aus und wie ist der Bitcoin im volkswirtschaftlichen Sinne einzuordnen? Mit diesen Fragestellungen wird sich in dieser Ausarbeitung auseinandergesetzt. Als Vergleichsgrose wurden dabei, auf Basis sorgfaltig ausgewahlter Literatur, die Aspekte realer Wahrungen nach ihren Funktionen, Eigenschaften und Formen untersucht. Anschliesend wurden die technischen Grundlagen der virtuellen Wahrung dargelegt, um ebenfalls den Bitcoin darauf anzuwenden. Dabei hat sich gezeigt, dass die digitalen Munzen als virtuelle Wahrung, gegenuber realen Wahrungen, noch deutliche Defizite aufweisen. Eine besonders gravierende Schwachstelle stellt dabei die hohe Volatilitat des Kurses dar. Sie sorgt dafur, dass der Bitcoin mit einer solchen Instabilitat nicht die Wertaufbewahrungsfunktion gewahrleisten kann. Da dies ein ausschlaggebendes Kriterium zur Erfullung der Geldfunktionen darstellt, kann der Bitcoin ebenfalls nicht die Rolle als Zahlungsmittel erfullen, wie es bei den realen Wahrungen der Fall ist.
This paper provides the first experimental evaluation of the participatory budgeting model showing that it increased public participation in the process of public decision making, increased local tax revenues collection, channeled larger fractions of public budgets to services stated as top priorities by citizens, and increased satisfaction levels with public services. These effects, however, were found only when the model was implemented in already-mature administratively and politically decentralized local governments. The findings highlight the importance of initial conditions with respect to the decentralization context for the success of participatory governance.
Decrits is a cryptocurrency in development that makes use of a novel consensus algorithm that does not require proof-of-work. This paper describes how the Decrits Consensus Algorithm (DCA) is as trustless as a proof-of-work algorithm while offering superior transaction security at virtually no cost.
Jelle van den Hooff, M. Frans Kaashoek, Nickolai Zeldovich
VerSum allows lightweight clients to outsource expensive computations over large and frequently changing data structures, such as the Bitcoin or Namecoin blockchains, or a Certificate Transparency log. VerSum clients ensure that the output is correct by comparing the outputs from multiple servers. VerSum assumes that at least one server is honest, and crucially, when servers disagree, VerSum uses an efficient conflict resolution protocol to determine which server(s) made a mistake and thus obtain the correct output.
This study was carried out to examine marketing of dried fish in Kwara State, Nigeria. The study used a combination of information discussions and questionnaires to collect data from 70 dried fish marketers in 2012. Data collected were analyzed with descriptive statistics, gross margin analysis and Gini coefficient analysis. The study revealed that dried fish marketing was dominated by active literate population that were most females and majority of the marketers finance their business through personal savings. Dried fish marketing channel in the study area was both centralized and decentralized. The profitability analysis suggests that dried fish marketing is a profitable venture in the study area. However, the marketing system was not efficient, indicating that the necessary marketing functions were not properly performed. Therefore, Government policies should be directed towards reducing labour cost, transportation charges, fish lost as waste and provision of credit by banks for the traders to expand their business.Key words: Dried fish, marketing, profitability analysis, marketing channel.
Most current digital currency schemes and associated ledgers are either centralized or completely distributed similar to the design adopted by Bitcoin. Centralized schemes enable accountability, but leave the privacy of users' identities and transactions in the hands of one organization. Distributed schemes can ensure better privacy but provide little accountability. In this paper we design a privacy-preserving proactively-secure distributed ledger and associated transaction protocols that can be used to implement an accountable digital currency that inherits the ledger's privacy and security features. One of the main technical challenges that we address is dealing with the increase in ledger size over time, an unavoidable aspect as the currency spreads and the ledger is required to be maintained for a long time in the future. We accomplish this by reducing the distributed (secret-shared) storage footprint and the required bandwidth and computation for proactively refreshing the ledger to ensure long-term confidentiality and security. In the full version, we provide performance analysis of some of the subprotocols to estimate the time required to perform transactions and the proactive refreshing of the ledger.
We study a model of incentivizing correct computations in a variety of cryptographic tasks. For each of these tasks we propose a formal model and design protocols satisfying our model's constraints in a hybrid model where parties have access to special ideal functionalities that enable monetary transactions. We summarize our results:
George Bissias, A. Pinar Ozisik, Brian Neil Levine, Marc Liberatore
A fundamental limitation of Bitcoin and its variants is that the movement of coin between addresses can be observed by examining the public block chain. This record enables adversaries to link addresses to individuals, and to identify multiple addresses as belonging to a single participant. Users can try to hide this information by mixing, where a participant exchanges the funds in an address coin-for-coin with another participant and address. In this paper, we describe the weaknesses of extant mixing protocols, and analyze their vulnerability to Sybil-based denial-of-service and inference attacks. As a solution, we propose Xim, a two-party mixing protocol that is compatible with Bitcoin and related virtual currencies. It is the first decentralized protocol to simultaneously address Sybil attackers, denial-of-service attacks, and timing-based inference attacks. Xim is a multi-round protocol with tunably high success rates. It includes a decentralized system for anonymously finding mix partners based on ads placed in the block chain. No outside party can confirm or find evidence of participants that pair up. We show that Xim's design increases attacker costs linearly with the total number of participants, and that its probabilistic approach to mixing mitigates Sybil-based denial-of-service attack effects. We evaluate protocol delays based on our measurements of the Bitcoin network.