Les transferis intra-européens de main d’oeuvre qualifiée: difficultés conceptuelles pour le management

Au-delà de la reconnaissance des difficultés réelles inhérentes aux voyages et à l’acclimatation à 1’étranger, les cadres qui travaillent en Europe ríont pas obtenu une reconnaissance managériale claire. Des phénomènes nouveaux, propres au «cadre européen», ont peut-être pour origine la naissance de règles particulières à 1’Union Européenne. Les directions de Ressources Humaines utilisent, en suivant un raisonnement analogique, les outils de mesure utilisés pour la gestion des RH en dimension nationale pour appréhender l’existence et les activités de cet « euromanager ». Celui-ci existe-t-il? Est-il un concept réel et opérationnel pour le management des ressources humaines à l’intemational? Comment doit-on reposer la problématique de la gestion de ces «cadres européens» dès lors qu 'emerge une spécificité européenne en la matière? Telles sont les questions auxquelles les auteurs proposent, en guise de réponse, quelques pistes de réflexion

Efficient Designated-Verifier Non-Interactive Zero-Knowledge Proofs of Knowledge

We propose a framework for constructing efficient designated-verifier non-interactive zero-knowledge proofs (DVNIZK) for a wide class of algebraic languages over abelian groups, under standard assumptions. The proofs obtained via our framework are proofs of knowledge, enjoy statistical, and unbounded soundness (the soundness holds even when the prover receives arbitrary feedbacks on previous proofs). Previously, no efficient DVNIZK system satisfying any of those three properties was known. Our framework allows proving arbitrary relations between cryptographic primitives such as Pedersen commitments, ElGamal encryptions, or Paillier encryptions, in an efficient way. For the latter, we further exhibit the first non-interactive zero-knowledge proof system in the standard model that is more efficient than proofs obtained via the Fiat-Shamir transform, with still-meaningful security guarantees and under standard assumptions. Our framework has numerous applications, in particular for the design of efficient privacy-preserving non-interactive authentication

Impact des formations à l'entrepreneuriat : vers de nouvelles méthodes d'évaluation

International audiencethose initiatives there is a need to develop a common framework to evaluate, compare and improve the design of those programmes. That framework should include both a set of clearly identified criteria that goes beyond the estimation of short-term microeconomic impact and a methodology to effectively measure them. The main objective of this article is to present such a framework, based on the theory of planned behaviour which could allow us to measure under the influences of independent variables. Facing the multiplication of entrepreneurship education programmes and the increasing resources allocated to those initiatives there is a need to develop a common framework to evaluate, compare and improve the design of those programmes. That framework should include both a set of clearly identified criteria that goes beyond the estimation of short-term microeconomic impact and a methodology to effectively measure them. The main objective of this article is to present such a framework, based on the theory of planned behaviour which could allow us to measure under the influences of independent variables.Si la question de la pertinence des enseignements en entrepreneuriat n'est plus discutée, celle de son évaluation reste d'actualité. Les programmes d'enseignement en entrepreneuriat sont fréquemment mis en œuvre avec le concours actif d'acteurs économiques et politiques. Ces derniers attendent généralement des résultats concrets en termes de création d'entreprises et d'emplois directs et indirects. Face à ces objectifs, un problème prend corps : l'évaluation des actions entreprises est une question complexe ; les indicateurs pertinents sont aujourd'hui peu nombreu

Motivations and Drawbacks Concerning Entrepreneurial Action – A Study of French PhD Students

The first part details the theoretical and practical aspects of the work carried out. There follows a description of the methods used, an analysis of the results obtained and a discussion of potential future action to be taken concerning students

Motivations and Drawbacks Concerning Entrepreneurial Action – A Study of French PhD Students

The first part details the theoretical and practical aspects of the work carried out. There follows a description of the methods used, an analysis of the results obtained and a discussion of potential future action to be taken concerning students

Two-Party ECDSA from Hash Proof Systems and Efficient Instantiations

ECDSA is a widely adopted digital signature standard. Unfortunately, efficient distributed variants of this primitive are notoriously hard to achieve and known solutions often require expensive zero knowledge proofs to deal with malicious adversaries. For the two party case, Lindell [Lin17] recently managed to get an efficient solution which, to achieve simulation-based security, relies on an interactive, non standard, assumption on Paillier’s cryptosystem. In this paper we generalize Lindell’s solution using hash proof systems. The main advantage of our generic method is that it results in a simulation-based security proof without resorting to non-standard interactive assumptions. Moving to concrete constructions, we show how to instantiate our framework using class groups of imaginary quadratic fields. Our implementations show that the practical impact of dropping such interactive assumptions is minimal. Indeed, while for 128-bit security our scheme is marginally slower than Lindell’s, for 256-bit security it turns out to be better both in key generation and signing time. Moreover, in terms of communication cost, our implementation significantly reduces both the number of rounds and the transmitted bits without exception.AppLicAtions de la MalléaBIlité en Cryptographi

Bandwidth-Efficient Threshold EC-DSA

Threshold Signatures allow n parties to share the power of issuing digital signatures so that any coalition of size at least t+1 can sign, whereas groups of t or less players cannot. Over the last few years many schemes addressed the question of realizing efficient threshold variants for the specific case of EC-DSA signatures. In this paper we present new solutions to the problem that aim at reducing the overall bandwidth consumption. Our main contribution is a new variant of the Gennaro and Goldfeder protocol from ACM CCS 2018 that avoids all the required range proofs, while retaining provable security against malicious adversaries in the dishonest majority setting. Our experiments show that-for all levels of security-our signing protocol reduces the bandwidth consumption of best previously known secure protocols for factors varying between 4.4 and 9, while key generation is consistently two times less expensive. Furthermore compared to these same protocols, our signature generation is faster for 192-bits of security and beyond.AppLicAtions de la MalléaBIlité en Cryptographi