Blockchain Papers

C.W. Jameson

No abstract is available for this record.

Hassan Kaghazchi, Hongxin Li, Michael Ulrich

No abstract is available for this record.

Gary B. Lamont

Abstract : Embedding desired behaviors in autonomous vehicles is a difficult problem at best and in general probably impossible to completely resolve in complex dynamic environments. Future technology demands the deployment of small autonomous vehicles or agents with large-scale decentralized swarming capabilities and associated behaviors. Various techniques inspired by biological self-organized systems as found in forging insects and flocking birds, revolve around control approaches that have simple localized rule sets that generate some of the desired emergent behaviors. To computationally develop such a system,an underlying organizational structure or framework is required to control agent rule execution. Thus, autonomous self-organization features are identified and coalesced into an entangled-hierarchical framework. The use of this self-organizing multi-objective evolutionary algorithmic approach dynamically determines the proper weighting and control parameters providing highly dynamic swarming behavior. The system is extensively evaluated with swarms of heterogeneous vehicles in a distributed simulation system with animated graphics. Statistical measurements and observations indicate that bio-inspired techniques integrated with an entangled self-organizing framework can provide desired dynamic swarming behaviors in complex dynamic environments.

Michael Backes, Matteo Maffei, Dominique Unruh

We devise an abstraction of zero-knowledge protocols that is accessible to a fully mechanized analysis. The abstraction is formalized within the applied pi-calculus using a novel equational theory that abstractly characterizes the cryptographic semantics of zero-knowledge proofs. We present an encoding from the equational theory into a convergent rewriting system that is suitable for the automated protocol verifier ProVerif. The encoding is sound and fully automated. We successfully used ProVerif to obtain the first mechanized analysis of (a simplified variant of) the Direct Anonymous Attestation (DAA) protocol. This required us to devise novel abstractions of sophisticated cryptographic security definitions based on interactive games. The analysis reported a novel attack on DAA that was overlooked in its existing cryptographic security proof. We propose a revised variant of DAA that we successfully prove secure using ProVerif.

Agostino Forestiero, Carlo Mastroianni, Giandomenico Spezzano

This article presents So-Grid, a set of bio-inspired algorithms tailored to the decentralized construction of a Grid information system that features adaptive and self-organization characteristics. Such algorithms exploit the properties of swarm systems, in which a number of entities/agents perform simple operations at the local level, but together engender an advanced form of swarm intelligence at the global level. In particular, So-Grid provides two main functionalities: logical reorganization of resources, inspired by the behavior of some species of ants and termites that move and collect items within their environment, and resource discovery, inspired by the mechanisms through which ants searching for food sources are able to follow the pheromone traces left by other ants. These functionalities are correlated, since an intelligent dissemination can facilitate discovery. In the Grid environment, a number of ant-like agents autonomously travel the Grid through P2P interconnections and use biased probability functions to: (i) replicate resource descriptors in order to favor resource discovery; (ii) collect resource descriptors with similar characteristics in nearby Grid hosts; (iii) foster the dissemination of descriptors corresponding to fresh (recently updated) resources and to resources having high quality of service (QoS) characteristics. Simulation analysis shows that the So-Grid replication algorithm is capable of reducing the entropy of the system and efficiently disseminating content. Moreover, as descriptors are progressively reorganized and replicated, the So-Grid discovery algorithm allows users to reach Grid hosts that store information about a larger number of useful resources in a shorter amount of time. The proposed approach features characteristics, including self-organization, scalability and adaptivity, which make it useful for a dynamic and partially unreliable distributed system.

Mohammad Alia, Azman Bin S amsudin

We proposed a new zero-knowledge proof of identity protocol based on Mandelbrot and Julia Fractal sets. The Fractal based zero-knowledge protocol was possible because of the intrinsic connection between the Mandelbrot and Julia Fractal sets. In the proposed protocol, the private key was used as an input parameter for Mandelbrot Fractal function to generate the corresponding public key. Julia Fractal function was then used to calculate the verified value based on the existing private key and the received public key. The proposed protocol was designed to be resistant against attacks. Fractal based zero-knowledge protocol was an attractive alternative to the traditional number theory zero-knowledge protocol.

Dan Hoornweg, Philip Lam, M. Saifullah Chaudhry

China recently surpassed the U.S. as the world's largest municipal solid waste (MSW) generator. In 2004 the urban areas of China generated about 190,000,000 tons of MSW and by 2030 this amount is projected to be at least 480,000,000 tons. No country has ever experienced as large, or as rapid, an increase in waste generation. Management of this waste has enormous domestic and international implications. This report provides a general sector background and identifies critical solid waste management issues - although it does not address the areas of hazardous waste, medical waste, sewage sludge, or waste pickers. However it does discuss waste quantities; information availability (quantity and waste cost); the decision-making process used to derive policy and strategically plan for technology selection, private sector involvement, cost recovery, inadequate public access, and participation in the planning process; facility operations; financing; institutional arrangements including inadequate decentralization of collection and transfer services and municipal capacity; private sector participation, and carbon financing.

Richard Sinnott, David Chadwick, T. Doherty, David Martín · 8 authors

Grids allow for collaborative e-Research to be undertaken, often across institutional and national boundaries. Typically this is through the establishment of virtual organizations (VOs) where policies on access and usage of resources across partner sites are defined and subsequently enforced. For many VOs, these agreements have been lightweight and erred on the side of flexibility with minimal constraints on the kinds of jobs a user is allowed to run or the amount of resources that can be consumed. For many new domains such as e-Health, such flexibility is simply not tenable. Instead, precise definitions of what jobs can be run, and what data can be accessed by who need to be defined and enforced by sites. The role based access control model (KBAC) provides a well researched paradigm for controlling access to large scale dynamic VOs. However, the standard RBAC model assumes a single domain with centralised role management. When RBAC is applied to VOs, it does not specify how or where roles should be defined or made known to the distributed resource sites (who are always deemed to be autonomous to make access control decisions). Two main possibilities exist based on either a centralized or decentralized approach to VO role management. We present the advantages and disadvantages of the centralized and decentralized role models and describe how we have implemented them in a range of security focused e-Research domains at the National e-Science Centre (NeSC) at the University of Glasgow.

Tasos Papadimitriou

Popular demands for democracy frequently transcend the liberal representative model towards more radical conceptions that include greater insistence on personal autonomy, and direct participation in decision-making processes. This paper looks at the direct action protests against the G8 summit that took place in the summer of 2005 in Scotland, casting a critical eye on the concept and practice of autonomism, its transformative potential and its ability to build a movement capable of challenging the existing order of things. It argues that despite representing a truly remarkable experiment in alternative ways of relating, organizing and acting, the protests failed to have any impact on the summit, something which exemplifies the fact that the relevance of decentralized networks of small autonomous collectivities is very often confined within the ‘activist ghetto’, tenuously engaged with the wider society and blighted by a selfindulging fetishization of organizational and other principles. [Article copies available for a fee from The Transformative Studies Institute. E-mail address: Website: http://www.transformativestudies.org ©2008 by The Transformative Studies Institute. All rights reserved.]

Eleonora Cavagnero

No abstract is available for this record.

International Monetary Fund

This paper focuses on the IMF’s training program as part of the Medium–Term Strategy (MTS) for capacity building in member countries.1 It updates Executive Directors on the current features of the program, reviews the efforts that have been made in recent years to strengthen the curriculum and to enhance value for money, and considers options for boosting external financing of training through charging and increased donor contributions. The paper also provides background for addressing the following issues: — Are the objectives of IMF training fully consistent with the broader objectives of the institution? And are these training objectives being met? — Is Fund training efficiently organized—i.e., is the current degree of decentralization sensible? — Are adequate evaluation and feedback mechanisms in place? —In the absence of market signals and with a large unsatisfied demand, how can we determine the “right” volume of training and how can we assess its worth?

Josh Gupta‐Kagan

Millions of American children are raised primarily by people other than their parents, mostly by grandparents and other kin, and millions more are raised by third parties for some period of their childhood. In most such situations, informal arrangements negotiated by family members and kinship networks effectively provide care for these children. Many cases, however, require some formal legal arrangement; third party custody orders are needed to obtain necessary services and benefits for children whose parents are absent, and to protect children in the rare but still significant instances in which a parent is abusive or neglectful.\nStates currently have widely varying means of adjudicating child custody disputes between parents and third parties. One Supreme Court case, Troxel v. Granville, addresses contests between parents and third parties. While Troxel ruled for the parent in that particular case, it neither represents a strong parents’ rights opinion nor does it provide states with clear guidance on how to shape third party custody statutes. This Article argues that states should enact child custody statutes according to three primary points. First, due to the wide range of situations in which a third party custody order may be necessary, states should permit a broad set of individuals to seek custody. Concerns that broad standing provisions would lead to a flood of meritless lawsuits are not borne out by actual data in states that have had nearly unlimited standing. Second, recognizing the constitutional primacy of the parent-child relationship, states should hold third parties to a high substantive standard, and require them to prove that parental custody would harm the child in some way. Any lesser standard — such as the best interests of the child standard applied in some states — insufficiently protects relationships between parents and children. Third, recognizing that the core parental right of the “care, custody and control” of a child is at stake, states should generally hold third parties to a clear and convincing burden of proof. Most states apply a preponderance burden or have not specified a burden. One exception should apply: When a third party has acted as a parent for a significant time and a child’s birth parent has not done so, then that parent’s constitutional rights are diminished, society’s interest in maintaining the long-term bond between the child and third party is enhanced, and a lower burden of proof should apply.

Ho‐fung Hung

This paper assesses the sources of potential instability of China's political economy by expositing the limits of the post-Mao regime of capital accumulation in historical and comparative perspectives. It argues that the new spatial and socio-political orders under this regime, while propelling China's economic miracle, also contribute to the internalization of the global overaccumulation crisis, which has been haunting the world capitalist system since the late 1960s, into China's national economy. Whereas decentralization of regulatory authority of the state accelerates overinvestment among local economic agents, breakdown of the Maoist social compact and the subsequent class polarization foster underconsumption. The resulting structural imbalance of the economy leads to the risk of falling profit across key sectors and China's over-reliance on the export market, the expansion of which has hinged much on the debt-financed and unsustainable consumption spree in the US. A full-fledged overaccumulation crisis within China in the form of extensive bankruptcy of enterprise, surging unemployment and financial turmoil will certainly trigger extensive global repercussions, given China's weight in the global economy. This crisis, nonetheless, is not inevitable, and can plausibly be averted through a recentralization of the state's economic regulatory functions and income redistribution. No matter whether and how such a crisis unfolds, nonetheless, it is not likely to stop the shift of the center of gravity of global capitalism to Asia in the long run.

Atsushi Tero, Kenji Yumiki, Ryo Kobayashi, Tetsu Saigusa · 5 authors

No abstract is available for this record.

Nurtanio Agus Purwanto

Previously mandated devolution of autonomy as part of the authorities, educational autonomy in fact have been outlined clearly where there is the role of central government and local governments, especially counties/cities in management education. In some cases the implementation was not running smoothly. It is caused by various perceptions, different way of looking at, as well as the varied interests as well. Implementation of the autonomy of education who now began to raise issues, among others, relating to teacher management, and decentralized management of facilities. An example is not being completion of the management of classrooms, where each year is always a problem. Based on data from the Ministry of National Education in the year 2009/2010 at the elementary level than 808,872 public elementary school classrooms, only 476,209 rooms in good condition. Knowingly education finance all educational levels when treated by the government alone of course is very heavy. The good news is the role of the community in providing educational facilities is increasing from year to year. Data from the Ministry of National Education in 2003/2003 at the elementary level there are 10,223 private schools, while in 2009/2010 rose to 12,689 private elementary school. Behind it was the number of primary schools decreased, because closed, merged or other causes so that the lower the provision of classrooms for the community. The increasing role of the community through private schools was encouraging, but if the public school diminishing public access would not be able to obtain an affordable education will be increasingly difficult as the choice of education in private schools would be problematic, especially costs for certain groups. Keywords: Journey, Education Policy

Vipul Goyal, Payman Mohassel, Adam Smith

No abstract is available for this record.

Jens Groth, Amit Sahai

Non-interactive zero-knowledge proofs and non-interactive witness-indistinguishable proofs have played a significant role in the theory of cryptography. However, lack of efficiency has prevented them from being used in practice. One of the roots of this inefficiency is that non-interactive zero-knowledge proofs have been constructed for general NP-complete languages such as Circuit Satisfiability, causing an expensive blowup in the size of the statement when reducing it to a circuit. The contribution of this paper is a general methodology for constructing very simple and efficient non-interactive zero-knowledge proofs and non-interactive witness-indistinguishable proofs that work directly for groups with a bilinear map, without needing a reduction to Circuit Satisfiability. Groups with bilinear maps have enjoyed tremendous success in the field of cryptography in recent years and have been used to construct a plethora of protocols. This paper provides non-interactive witness-indistinguishable proofs and non-interactive zero-knowledge proofs that can be used in connection with these protocols. Our goal is to spread the use of non-interactive cryptographic proofs from mainly theoretical purposes to the large class of practical cryptographic protocols based on bilinear groups.

Jens Groth, Yuval Ishai

No abstract is available for this record.

Dario Catalano, Mario Di Raimondo, Dario Fiore, Mariagrazia Messina

Zero knowledge sets (ZKS), introduced by Micali, Rabin, and Kilian in 2003, allow a prover to commit to a secret set$S$in a way such that it can later prove, non interactively, statements of the form$x\in S$(or$x\notin S$), without revealing any further information (on top of what explicitly revealed by the inclusion/exclusion statements above) on$S$, not even its size. Later, Chaseabstracted away the Micali, Rabin, and Kilian's construction by introducing an elegant new variant of commitments that they called (trapdoor) mercurial commitments. Using this primitive, it was shown how to construct zero knowledge sets from a variety of assumptions (both general and number theoretic). This paper introduces the notion of trapdoor$q$-mercurial commitments (${\ssr qTMC}$s), a notion of mercurial commitment that allows the sender to commit to an ordered sequence of exactly$q$messages, rather than to a single one. Following the previous work, it is shown how to construct ZKS from${\ssr qTMC}$s and collision resistant hash functions. Then, it is presented an efficient realization of${\ssr qTMC}$s that is secure under the so called Strong Diffie Hellman (SDH) assumption, a number theoretic conjecture recently introduced by Boneh and Boyen. Using such scheme as basic building block, it is obtained a construction of ZKS that allows for proofs that are much shorter with respect to the best previously known implementations. In particular, for an appropriate choice of the parameters, our proofs are up to 33% shorter for the case of proofs of membership, and up to 73% shorter for the case of proofs of nonmembership. Experimental tests confirm practical time performances.

Benin

The project development objectives of the Additional Financing for Second Decentralized City Management Project of Benin remain unchanged: to increase access to infrastructure and basic services for residents of Benin's primary cities (Cotonou, Porto- Novo, and Parakou) and selected secondary cities (Abomey-Calavi, Lokossa, and Kandi). The additional financing would scale up the project impact in terms of the number of people gaining access to roads and being protected from periodic flooding. It is within this framework that the Project will help strengthen the infrastructure of roads and storm-drainage in the cities of Cotonou, Porto-Novo and Parakou. The realization and implementation of selected works in this program could have negative effects on the cultural and human affairs. These impacts are traditionally the subject of a management plan for environmental and social impacts. However, when these impacts lead to involuntary displacement of persons, a special procedure is scheduled to limit these impacts and to minimize or compensate for the property losses and activities incurred by these populations.

Aydin Behnad, Taraneh Eghlidos

A Publicly Veriable Secret Sharing (PVSS) scheme, as introduced by Stadler, has a feature where anyone, besides the participants, can verify the validity of the shares distributed by the dealer. Schoenmakers added a new feature, by providing a proof of correctness of the shares released by the players in the reconstruction process. This protocol is claimed to be an improvement on Stadler's and Fujisaki-Okamoto's, both in eciency and in the type of intractability assumptions. However, Young-Yung improved Schoenmakers' PVSS, using a Discrete-Log instead of a Decision Die-Hellman. In this paper, a new PVSS is presented, having an intrinsic dierence with its predecessors, that is, the participants can prove the validity of their given shares, implicitly, proving their membership by a zero-knowledge protocol. This feature prevents cheaters from participating in the reconstruction process to gain valid shares. Hence, the new proposed PVSS is more secure than previous ones. Besides, the dealer only sends the amount of commitments limited to the threshold value, regardless of the number of shareholders; this leads to a more dynamic protocol.

Alfredo Espitia Beltran, Karen Ortega, Eduardo Romero, Iván Jaramillo

The main objective of this project was to design, develop and validate a digital signature in a security device for telemedicine applications. Medical domain requires high security conditions for archiving since the information to be protected contains images, diagnosis, personal information of the patients and physicians involved in the telemedicine process. The developed strategy consists in a USB device which allows proper authentication in the information system using a conventional public-private key scheme, through a zero knowledge proof algorithm that guarantees the privacy of the personal password. Once the user is accepted, the device also makes possible the generation of the digital signature required for generated documents.

Liu Quan, Zheng Chen, Zhou Zude

A new buyer-seller watermarking protocol is proposed by applying a double encryption method and a novel mechanism of embedding a buyer's watermark. The protocol can effectively prevent against collusion attacks and the man in the middle attack if the third party is not trusted. Also, based on the proposed scheme for the first-hand transaction, a new buyer-reseller watermarking protocol and a formal multi-party watermarking protocol are also proposed. The proposed buyer-resell watermarking protocol only needs the original seller to provide transfer certificate and encryption-decryption service to support the second-hand transaction, and the multi-party watermarking protocol with distributed certificate authorities can overcome the difficulty in the combination of multicast mechanism with multiple unique watermarks and allow a seller to multicast the watermarked digital contents and key transaction information to n buyers. Furthermore, the idea of zero knowledge proof is also applied into the proposed scheme to allow the seller to take an effective control on the task performed by the third party.

Ngot Phu Bui, Young-Tack Park, TaeChoong Chung

No abstract is available for this record.