1,720,963 research outputs found
Functional Cryptanalysis: Application to reduced-round Xoodoo
Get PDFThis paper proposes functional cryptanalysis, a flexible and versatile approach to analyse symmetric-key primitives with two primary features. Firstly, it is a generalization of multiple attacks including (but not limited to) differential, rotational and rotational-xor cryptanalysis. Secondly, it is a theoretical framework that unifies all of the aforementioned cryptanalysis techniques and at the same time opens up possibilities for the development of new cryptanalytic approaches. The main idea of functional cryptanalysis is the usage of binary relations in the form of functions, hence the name functional, instead of binary operations like in a classical settings of differential -like cryptanalysis. We establish the theoretical foundations of functional cryptanalysis from standard terminologies. This work also presents an interpretation of functional cryptanalysis from the point of view of commutative algebra. In particular, we exhibit an algorithm to compute the functional probability (hence differential, rotational, and rotational-xor probability) using Grobner bases. We demonstrate the applicability of functional cryptanalysis against reduced-round Xoodoo and compare it against the best differential. To avoid dealing with invalid differential trails, we propose a method to construct a valid differential trail using Satisfiability Modulo Theory (SMT). To the best of our knowledge, this is the first time the SMT model is used to construct a valid differential while previous approaches rely on Mixed-Integer Linear Programming (MILP) model. Lastly, we remark that the use of non-translation functionals shares analogous advantages and limitations with the use of nonlinear approximations in linear cryptanalysis
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
Relating Undisturbed Bits to Other Properties of Substitution Boxes?
Get PDFAbstract. Recently it was observed that for a particular nonzero in-put difference to an S-Box, some bits in all the corresponding output differences may remain invariant. These specific invariant bits are called undisturbed bits. Undisturbed bits can also be seen as truncated differ-entials with probability 1 for an S-Box. The existence of undisturbed bits was found in the S-Box of Present and its inverse. A 13-round improbable differential attack on Present was provided by Tezcan and without using the undisturbed bits in the S-Box an attack of this type can only reach 7 rounds. Although the observation and the cryptanalytic application of undisturbed bits are given, their relation with other prop-erties of an S-Box remain unknown. This paper presents some results on mathematical properties of S-Boxes having undisturbed bits. We show that an S-Box has undisturbed bits if any of its coordinate functions has a nontrivial linear structure. The relation of undisturbed bits with other cryptanalytic tools such as difference distribution table (DDT) and linear approximation table (LAT) are also given. We show that autocorrelation table is proven to be a more useful tool, compared to DDT, to obtain all nonzero input differences that yield undisturbed bits. Autocorrelation table can then be viewed as a counterpart of DDT for truncated differ-ential cryptanalysis. Given an n×m balanced S-Box, we state that the S-Box has undisturbed bits whenever the degree of any of its coordinate function is quadratic
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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