1,720,960 research outputs found

    Robust decentralized authentication for public keys and geographic location:

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    Authentication has traditionally been done either in a decentralized manner with human assistance or automatically through a centralized security infrastructure. In the security infrastructure approach, a central trusted authority takes on the responsibility of authenticating participants within its domain of control. While the security infrastructure approach works well in traditional organizations, it does not address the needs of open membership systems. We propose automatic decentralized authentication mechanisms for peer-to-peer systems, email systems, and ad-hoc networks. Our byzantine fault tolerant public-key authentication protocol (BPKA) provides decentralized authentication to peer-to-peer systems with honest majority. Authentication is done over an insecure asynchronous network without using trusted third parties or human input. We also authenticate public keys in the email environment through our social-group key authentication protocol (SGKA). The protocol provides end-to-end authentication at the email client without using infrastructure or centralized authorities. Finally, location authentication in ad-hoc networks is proposed through our geographical secure path routing protocol (GSPR). The protocol authenticates geographic locations of anonymous nodes in order to provide location authentication and anonymity simultaneously.Ph.D.Includes bibliographical references (p. 121o-128)by Vivek Patha

    Byzantine Fault Tolerant Authentication

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    A Byzantine fault tolerant public key infrastructure is presented. It aims to fulfill the authentication requirements of large distributed systems consisting of semi-trusted parties. The distributed trust model does not demand the existence of predefined trusted parties and provides authentication if more than a threshold of the participants are honest. A voting based protocol implements distributed trust and supports dynamic membership without fail safe multi-cast or synchrony. This paper describes the system design and discusses its applicability to mobile networks and peer-to-peer systems on the Internet. It also demonstrates the Byzantine fault tolerance of distributed authentication.Technical report DCS-TR-49

    Growing Businesses Organically on the Social Farm

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    We propose to create and operate businesses on top of online social networks through our Social Farm model. The Social Farm leverages the connectivity and trust relationships available in online social networks to create and operate businesses using the programming interface provided by online social networks. Our proposal aims to automate the tasks of finding partners, implementing the business workflow, managing profits and customer reputation, and managing the day-to-day operations of the business. This paper presents the Social Farm model and architecture, as well as, a description of a Social Farm prototype we developed for Facebook.Technical report DCS-TR-65

    Securing Geographical Routing in Mobile Ad-Hoc Networks

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    We present geographical secure path routing, an infrastructure free geographic routing protocol, that is resilient to disruptions caused by malicious or faulty nodes. Geographic locations of anonymous nodes are authenticated in order to provide location authentication and location privacy simultaneously. Our protocol also authenticates the routing paths taken by individual messages. This provides a basis for geographic security policies. This paper discusses the design and attack resistance of the secure geographic routing protocol. The overhead of location authentication is investigated under various scenarios through network simulation. Results show that the presence of malicious nodes increases the routing path length. A data delivery rate of better than 80% is sustained even if 40% of the nodes are malicious.Technical report DCS-TR-63

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author Index

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