1,721,007 research outputs found
An Exploration of the Kolmogorov-Smirnov Test as a Competitor to Mutual Information Analysis
Get PDFA theme of recent side-channel research has been the quest for distinguishers which remain effective even when few assumptions can be made about the underlying distribution of the measured leakage traces. The Kolmogorov-Smirnov (KS) test is a well known non-parametric method for distinguishing between distributions, and, as such, a perfect candidate and an interesting competitor to the (already much discussed) mutual information (MI) based attacks. However, the side-channel distinguisher based on the KS test statistic has received only cursory evaluation so far, which is the gap we narrow here. This contribution explores the effectiveness and efficiency of Kolmogorov-Smirnov analysis (KSA), and compares it with mutual information analysis (MIA) in a number of relevant scenarios ranging from optimistic first-order DPA to multivariate settings. We show that KSA shares certain ‘generic’ capabilities in common with MIA whilst being more robust to noise than MIA in univariate settings. This has the practical implication that designers should consider results of KSA to determine the resilience of their designs against univariate power analysis attacks
Implementation and Evaluation of an SCA-Resistant Embedded Processor
No full textSide-channel analysis (SCA) attacks are a threat for many embedded applications which have a need for security. With embedded processors being at the very heart of such applications, it is desirable to address SCA attacks with countermeasures which "naturally" fit deployment in those processors. This paper describes our work in implementing one such protection concept in an ASIC prototype and our results from a practical evaluation of its security. We are able to demonstrate that the basic principle of limiting the “leaking” portion of the processor works rather well to reduce the side-channel leakage. From this result we can draw valuable conclusions for future embedded processor design. In order to minimize the remaining leakage, the security concept calls for the application of a secure logic style. We used two concrete secure logic styles (iMDPL and DWDDL) in order to demonstrate this increase in security. Unfortunately, neither of these logic styles seems to do a particularly good job as we were still able to attribute SCA leakage to the secure-logic part of the processor. If a better suited logic style can be employed we believe that the overall leakage of the processor can be further reduced. Thus we deem the evaluated security concept as a viable method for protecting embedded processors.Side-channel analysis (SCA) attacks are a threat for many embedded applications which have a need for security. With embedded processors being at the very heart of such applications, it is desirable to address SCA attacks with countermeasures which "naturally" fit deployment in those processors. This paper describes our work in implementing one such protection concept in an ASIC prototype and our results from a practical evaluation of its security. We are able to demonstrate that the basic principle of limiting the “leaking” portion of the processor works rather well to reduce the side-channel leakage. From this result we can draw valuable conclusions for future embedded processor design. In order to minimize the remaining leakage, the security concept calls for the application of a secure logic style. We used two concrete secure logic styles (iMDPL and DWDDL) in order to demonstrate this increase in security. Unfortunately, neither of these logic styles seems to do a particularly good job as we were still able to attribute SCA leakage to the secure-logic part of the processor. If a better suited logic style can be employed we believe that the overall leakage of the processor can be further reduced. Thus we deem the evaluated security concept as a viable method for protecting embedded processors
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
Study of the resistance of symmetric-key algorithms against modern cryptanalysis
No full textL’objectif de cette thèse est de proposer de nouvelles pistes de recherche dans l’état de l’art afin de sécuriser les algorithmes cryptographiques au sein d’un circuit électronique. Notre axe d’étude principal s’articule autour de la contre-mesure des implémentations à seuil, résistante contre les attaques par observations en présence de glitches. Ces derniers phénomènes apparaissent dans un circuit électronique de manière aléatoire et sont à l’origine de nombreuses attaques en cryptanalyse. Nous étudions l’application des implémentations à seuil sur la cryptographie symétrique. Dans un premier temps, nous contribuons à la littérature cryptographique par la conception de nouvelles implémentations à seuil applicables sur un grand nombre d’algorithmes symétriques. Les travaux réalisés sont appuyés par des preuves mathématiques formelles et permettent de contrer les attaques physiques par observations en présence de glitches. Par ailleurs, nos recherches ont également débouché à la proposition de deux brevets au sein de l’entreprise STMicroelectronics, participant ainsi au processus d’innovation industriel. Dans un second temps, nous nous intéressons à l’étude de l’algorithme symétrique SM4 et sa résistance face à la cryptanalyse actuelle. Les travaux obtenus permettent de centraliser les différentes implémentations du SM4 sécurisées contre les attaques par observations proposées dans l’état de l’art et d’offrir une visibilité sur les performances de ces constructions. Nous contribuons également à la recherche académique par la première proposition d’une implémentation à seuil du SM4, mathématiquement résistante contre les attaques par observations en présence de glitches.The goal of this thesis is to contribute to the state-of-the-art by proposing new areas of research in order to secure cryptographic algorithms within an embedded device.Our main focal axis is organized around the countermeasure called threshold implementations which is known to be resistant against side-channel analysis attacks in the presence of glitches.These latter phenomenon occur randomly within an electronic circuit and lead to numerous attacks in cryptanalysis. We study the application of threshold implementations on symmetric-key cryptography.In a first phase, we participate to the cryptographic litterature by designing new threshold implementations easily applicable on a large variety of symmetric-key algorithms. Our countermeasures are provable mathematically secured against side-channel analysis attacks in the presence of glitches. In comparison with the recent publications of the state-of-the-art, we adress new issues and we assure similar or better performances. Therefore, our research has resulted in two patents within STMicroelectronics, thereby contributing to the industrial innovation process.In a second phase, we are interested in the study of the symmetric-key algorithm SM4 and its resistance against side-channel analysis attacks. The works obtained allow to centralize the proposed SM4 countermeasures against side-channel analysis attacks of the state-of-the-art and offer a visibility on the software performances of these constructions. We finally introduce the first threshold implementation of the SM4 algorithm. Our construction is provably mathematically resistant against side-channel analysis attacks in the presence of glitches
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
Smart Card Research and Advanced Applications: 10th IFIP WG 8.8/11.2 International Conference, CARDIS 2011, Leuven, Belgium, September 14-16, 2011, Revised Selected Papers
No full textInternational audienceBook Front Matter of LNCS 707
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