1,720,996 research outputs found
Verified security protocol modeling and implementation with AnBx
No full textAnBx è un'estensione della notazione Alice & Bob per la descrizione di protocolli, ed è utilizzato come linguaggio di specifica per la modellazione puramente dichiarativa dei protocolli distribuiti. AnBx è costituito da un insieme di astrazioni sui dati e sui modi di comunicazione che forniscono il supporto di base per le proprietà di sicurezza ad alto livello, schermando i dettagli della infrastruttura crittografica sottostante.
AnBx, essendo implementato sul tool di verifica OFMC, è utilizzabile non solo per specifica e la progettazione ma anche per l'analisi della sicurezza dei protocolli distribuiti. Inoltre il framework consente la generazione automatica del codice Java di protocolli descritti in AnBx, mantenendo separate la logica del protocollo dalla logica dell'applicazione. L'efficacia del nostro approccio è mostrata nella specifica ed nell'analisi di due protocolli di pagamento elettronico usati nel mondo reale, realizzando proprietà di sicurezza più forti e più scalabili rispetto a quelle delle versioni originali.
Nella seconda parte della tesi analizziamo in maniera formale il sistema di comunicazione veicolare sicura (SeVeCom) utilizzando il framework AIF, che è basato su una nuova tecnica di set-abstraction.
Nel corso del lavoro abbiamo trovato due nuovi attacchi, e verificato che sotto ragionevoli ipotesi il sistema è sicuro.AnBx is an extension of the Alice & Bob notation for protocol narrations to serve as a specification language for a purely declarative modelling of distributed protocols. AnBx is built around a set of communication and data abstractions which provide primitive support for the high-level security guarantees, and help shield from the details of the underlying cryptographic infrastructure.
Being implemented on top of the OFMC verification tool, AnBx serves not only for specification and design, but also for security analysis of distributed protocols. Moreover the framework, keeping apart the protocol logic from the application logic, allow for automatic generation of Java source code of protocols specified in AnBx.
We demonstrate the practical effectiveness of our approach with the specification and analysis of two real-life e-payment protocols, obtaining stronger and more scalable security guarantees than those offered by the original ones.
In the second part of the thesis we formally analyze the Secure Vehicle Communication system (SeVeCom), using the AIF framework which is based on a novel set-abstraction technique. We report on two new attacks found and verify that under some reasonable assumptions, the system is secure
Security Protocol Specification and Verification with AnBx
Get PDFDesigning distributed protocols is complex and requires actions at very different levels: from the design of an interaction flow supporting the desired application-specific guarantees, to the selection of the most appropriate network-level protection mechanisms.
To tame this complexity, we propose AnBx, a formal protocol specification language based on the popular Alice & Bob notation. AnBx offers channels as the main abstraction for communication, providing different authenticity and/or confidentiality guarantees for message transmission.
AnBx extends existing proposals in the literature with a novel notion of forwarding channels, enforcing specific security guarantees from the message originator to the final recipient along a number of intermediate forwarding agents. We give a formal semantics of AnBx in terms of a state transition system expressed in the AVISPA Intermediate Format. We devise an ideal channel model
and a possible cryptographic implementation, and we show that, under mild restrictions, the two representations coincide, thus making AnBx amenable to automated verification with different tools. We demonstrate the benefits of the declarative specification style distinctive of AnBx by revisiting the design of two existing e-payment protocols, iKP and SET
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Typing and compositionality for security protocols: A generalization to the geometric fragment
Get PDFWe integrate, and improve upon, prior relative soundness results of two kinds. The first kind are typing results showing that any security protocol that fulfils a number of sufficient conditions has an attack if it has a well-typed attack. The second kind considers the parallel composition of protocols, showing that when running two protocols in parallel allows for an attack, then at least one of the protocols has an attack in isolation. The most important generalization over previous work is the support for all security properties of the geometric fragment
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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