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Concept

Morphisme de groupes

Publications associées (10)

On the lifting of the Dade group

Jacques Thévenaz, Caroline Lassueur

For the group of endo-permutation modules of a finite p-group, there is a surjective reduction homomorphism from a complete discrete valuation ring of characteristic 0 to its residue field of characteristic p. We prove that this reduction map always has a ...

2019

Characteristic classes as complete obstructions

Martina Rovelli

In the first part of this paper, we propose a uniform interpretation of characteristic classes as obstructions to the reduction of the structure group and to the existence of an equivariant extension of a certain homomorphism defined a priori only on a sin ...

SPRINGER HEIDELBERG2019

Every simple compact semiring is finite

A Hausdorff topological semiring is called simple if every non-zero continuous homomorphism into another Hausdorff topological semiring is injective. Classical work by Anzai and Kaplansky implies that any simple compact ring is finite. We generalize this r ...

Elsevier Science Bv2016

Short Undeniable Signatures Based on Group Homomorphisms

Serge Vaudenay, Jean Monnerat

This paper is devoted to the design and analysis of short undeniable signatures based on a random oracle. Exploiting their online property, we can achieve signatures with a fully scalable size depending on the security level. To this end, we develop a gene ...

Springer Verlag2011

Annihilating Polynomials for Quadratic Forms

Let K be a field with char(K) ≠ 2. The Witt-Grothendieck ring (K) and the Witt ring W (K) of K are both quotients of the group ring ℤ[𝓖(K)], where 𝓖(K) := K*/(K*)2 is the square class group of K. Since ℤ[𝓖(K)] is integra ...

EPFL2010

Two variants of the support problem for products of abelian varieties and tori

Let G be the product of an abelian variety and a torus defined over a number field K. Let P and Q be K-rational points on G. Suppose that for all but finitely many primes p of K the order of (Q mod p) divides the order of (P mod p). Then there exist a K-en ...

2009

Method to generate, verify and deny an undeniable signature

Serge Vaudenay, Jean Monnerat

The aim of the invention is to propose the generation, verification and denial of an undeniable signature which has a size smaller than the currently available undeniable signatures, i.e. less than 80 bits. This aim is achieved by the method to generate an ...

2008

Convolution Operators And Homomorphisms Of Locally Compact Groups

Let 1 < p < infinity, let G and H be locally compact groups and let c) be a continuous homomorphism of G into H. We prove, if G is amenable, the existence of a linear contraction of the Banach algebra CVp (G) of the p-convolution operators on G into CVp (H ...

Cambridge University Press2008

Short undeniable signatures : design, analysis, and applications

Jean Monnerat

Digital signatures are one of the main achievements of public-key cryptography and constitute a fundamental tool to ensure data authentication. Although their universal verifiability has the advantage to facilitate their verification by the recipient, this ...

EPFL2006

Optimization of the MOVA Undeniable Signature Scheme

Serge Vaudenay, Jean Monnerat

This article presents optimization results on the MOVA undeniable signature scheme presented last year by Monnerat and Vaudenay at PKC'04 as well as its generalization proposed at Asiacrypt'04 which is based on a secret group homomorphism. The original MOV ...

2005

Publications associées (10)