2-round Substitution-Permutation and 3-round Feistel Networks have bad Algebraic Degree

We study algebraic degree profile of reduced-round block cipher schemes. We show that the degree is not maximal with elementary combinatorial and algebraic arguments. We discuss on how it can be turned into distinguishers from balanced random functions

Approximating Addition by XOR: how to go all the way

In this paper, we study approximation of addition by XOR, taking P. Sarkar\u27s publication~\cite{bib:sarkar} as the reference work and starting point. In this work, among various results, it was claimed that explicit formulas seemed difficult to obtain when the number $n$ of summands is more than $5$. In the first part of our work, we show a systematic way to find explicit formulas: the complexity to compute them is $O(n^3)$, which allows large values of $n$. We present some numerical computation and point out a - conjectural - observation on the coefficients. In the second part, we study a generalization of P. Sarkar\u27s work to $q$-ary addition, instead of binary. We show that the mechanics of the addition is essentially the same as in the binary case. In particular, sequence of carries behaves very similarly: it is a Markov chain whose transition matrix can be computed. Running some experiments on small values of $n$ leads us to a conjecture, the first part of which is intuitive and the second part of which reveals an amazing coincidence (and is probably not!). Finally, in a section titled ``very last news\u27\u27, we refer to a paper published by Holte in 1997, that was brought to us after our first post and that we had missed before. It happens that this paper studies the topic and solves a major part of our open problems. Henceforth, the present post is an updated version of our previous ``Approximating Addition by XOR: how to go (a little) further than P. Sarkar\u27\u27, taking into account this previous Holte\u27s reference

Miniaturization of Microwave Biosensor for Non-invasive Measurements of Materials and Biological Tissues

Non-invasive planar complementary split ring resonators (CSRRs) coupled to microstrip line for measuring the dielectric properties of materials and biological tissues are presented in this paper. The expectations of health professionals are increasingly turning to less invasive surgical procedures and treatments. In particular, the monitoring of vital parameters (sweat, water in the lungs, etc.) or the evolution of certain pathologies, such as cancer cells, could be observed regularly if suitable devices were developed and could especially replace traditional invasive method. Appropriate miniaturized RF or microwave devices could be an alternative for some medical diagnostic applications. These devices would make it possible to determine the dielectric characteristics of biological tissues, which represent their real pathological states. It would thus be possible, by means of dielectric contrast measurements, to follow the evolution of pathology as well as the vital parameters of a patient. The objective of this research is to produce a prototype biosensor that is suitable for measurements on biological tissues and that can be miniaturized to enhance its spatial sensitivity. This work focuses on the design, electromagnetic simulations and characterization of a new miniaturized biosensors operating between 1 and 10 GHz. The ex-vivo experimental results will be shown by measuring the S-parameters of various materials and animal biological tissues. The extraction of the dielectric parameters of these samples is obtained by the measurements of material

Polarization of thick polyvinylidene fluoride/trifluoroethylene copolymer films

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Spinoza

"Spinoza", second edition. Encyclopedia entry for the Springer Encyclopedia of EM Phil and the Sciences, ed. D. Jalobeanu and C. T. Wolfe

Pratos e mais pratos: louças domésticas, divisões culturais e limites sociais no Rio de Janeiro, século XIX

Reply to ten comments on a paper published in the last issue of this journal. The discussion follows along six main lines: History museums, identity, ideology and the category of nation; the need of material collections and their modalities: patrimonial, operational, virtual; theater versus laboratory; visitors and their ambiguities; Public History: the museum and the academy.Resposta aos comentários de dez especialistas que contribuíram no debate de texto publicado no último número desta revista. A discussão orientou-se segundo seis tópicos principais: museus históricos, identidade, ideologia e a categoria de nação; a necessidade de acervos materiais e suas modalidades: acervo patrimonial, operacional, virtual; teatro versus laboratório; o público e suas ambigüidades; História Pública: o museu e a Academia