411 research outputs found
A New Method For The Generation Of Strong Prime Numbers
No full text: Since the discovery of the RSA encryption scheme, primality domain has gained much interest. For the generation of keys for this code, two prime numbers are used. Amongst the different methods to deal with this problem, we are here interested in generation of certified prime numbers and we present a new method less costly in terms of computation in regard of the other methods of generation for a given size of prime numbers. Key-words: Cryptography; Prime number generation (R'esum'e : tsvp) y email: [email protected] CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE Centre National de la Recherche Scientifique Institut National de Recherche en Informatique (URA 227) Universite de Rennes 1 -- Insa de Rennes et en Automatique -- unite de recherche de Rennes Une nouvelle m'ethode de g'en'eration de nombre premiers robustes R'esum'e : Depuis l'invention du sch'ema d'encryption RSA, le domaine de la primalit'e a connu un regain d'int'eret. Pour la g'en'eration des cl'es de ce code, deux no..
A (doubly) elementary formula for prime numbers
No full textInternational audienceIn this paper the author gives formulas for the prime counting function and for the n-th prime numbers. These formulas only use elementary functions. Moreover their proof requires only elementary facts of number theory, so that the title of the paper is justified
Selection procedure for binary turbocode permutation parameters
No full textInternational audiencePermutation design is a crucial point for turbocodes in terms of error correction performance. Many permutation design models have been proposed to deal with this point. However, most of them are defined in terms of several free parameters that have to be correctly chosen. In this article, we describe a new criterion to optimize the choice of the permutation. Then we use it with two other standard criteria to design a procedure which enables only those permutation sets giving good performance to be selected
Constructions of LDPCs from elliptic curves over finite fields
No full textInternational audienceIn this paper, a new framework for the construction of low density parity check codes is exposed. Parameters of the new codes are estimated, performance simulations are reported and compared to some classical constructions
Linear binary codes arising from finite groups
No full textInternational audienceIn this paper, we describe constructions of majority logic decodable codes which stem out description of finite groups. To this end, we generalize some previous studies of Tonchev, Key and Moori on codes from finite groups. We also extend some results obtained by Rudolph for majority logic decodable codes. Finally, we describe applications of these codes in the area of soft-decoding techniques
Wave-front phase retrieval in transmission electron microscopy via ptychography
No full textThere are many different strategies that allow the solving of the well-known phase problem corresponding to the loss of phase information during a physical measurement. In microscopy, and, in particular, in transmission electron microscopy, most of these strategies focus on the retrieval of high-resolution information with the importance of lower resolution data often overlooked. Ptychography offers a means to investigate such data. Ptychography is a robust diffractive imaging technique with fast convergence for phase retrieval but, until now, has not been applied at the nanoscale. In this paper, we use the ptychographical iterative engine to retrieve the phase change at the exit plane of metallic nanoparticles using a conventional transmission electron microscope. Ptychographical reconstructions yielded images with a phase resolution of π/10 and a spatial resolution of 1 nm. These results stand as a first step toward aberration-free lensless imaging. The technique lends itself to be an alternative to off-axis electron holography or focal series reconstructio
Fast decoding of binary quadratic residue codes
No full textInternational audienceIn a recent article, Yi et al. proposed an algorithm for the decoding of binary quadratic residue codes with memory requirements. In this letter, this algorithm is modified in order to dramatically improve the decoding speed. The case of the (89,45,17) binary quadratic residue code is used to illustrate the new algorithm
La cosmétologie à travers les âges
No full textDie Kosmetologie im Laufe der Zeit.
Die Verfasserin gibt eine kurze Übersicht der Kosmetologie vom alten Aegypten an bis zum 19. Jahrhundert.Cosmetology across the ages.
The author paints a quick sketch of cosmetology from Ancient Egypt to the 19th century.de Roeck-Holtzhauer Yannick. La cosmétologie à travers les âges. In: Revue d'histoire de la pharmacie, 76ᵉ année, n°279, 1988. pp. 397-399
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