Un nouveau modèle de correspondance pour un service de messagerie électronique avancée

The ease of use and efficiency of the email service contributed to its widespread adoption. It became an essential service and authorizing multiples and various uses (private, professional, administrative, governmental, military ...). However, all existing systems are technically reduced to the implementation of global policies, compiling in a static way a limited set of features. These approaches prevent differentiated adaptations of the system to the uses. The rigid and monolithic nature of these policies can moreover lead to unnecessary execution of expensive treatments or to the inability to simultaneously satisfy conflicting requirements. We address this problem of the evolution of e-mail in the general context of interpersonal communication of a sender to a receiver. We identify the sender's intention of communication, as a key parameter of any interpersonal communication, insofar as it allows to finely discriminate the successful communications, between all the ones that are understood. A second parameter which is orthogonal to the first, defined as the context of the sender, is important because it allows to determine the successful aspect of an interpersonal communication. The declination of these two parameters in the electronic mail led us to define the concept of electronic correspondence. This one is a generalization of the email the implementation of which provides a sufficient condition of qualification successful exchanges via this medium. A correspondence allows taking into account for each message, the intention of communication and context of its sender. Its implementation requires in certain points of the network, the enforcement of specific policies depending of an administrative domain and which take as argument the intention of communication and the current context of the sender. A second benefit provided by this concept concerns the level of customization of messaging reaching a maximum granularity, because it can be applied in a differentiated way, to each message instance. These works led to the description of a representative architecture and the definition of three extensions to existing standards (SUBMISSION, IMF and S/MIME). Our approach has been illustrated through two main use cases, compliant with recommended specifications for administration (RGS - Référentiel Général de Sécurité) and military (MMHS - Military Message Handling System) domains.Le service de courrier électronique en raison de sa simplicité d'utilisation combinée à son efficacité, a constitué l'un des principaux vecteurs de popularisation d'Internet. Il est devenu un service incontournable dont la richesse s'exprime au travers des usages variés et multiples qu'il autorise (privé, professionnel, administratif, officiel, militaire...). Cependant, toutes les réalisations existantes se réduisent techniquement à la mise en oeuvre de politiques globales, compilant de façon statique un ensemble limité de fonctionnalités. Ces approches ne permettent pas au système de s'adapter de façon différenciée aux usages. De plus, le caractère rigide et monolithique de ces politiques peut parfois conduire à l'exécution inutile de traitements coûteux ou à l'impossibilité de satisfaire simultanément des exigences contradictoires. Nous abordons cette problématique de l'évolution de la messagerie électronique dans le cadre général de la communication interpersonnelle d'un locuteur vers un interlocuteur. Nous identifions l'intention de communication du locuteur, comme un paramètre clé de toute communication interpersonnelle, dans la mesure où il permet de discriminer finement les communications réussies, parmi toutes celles qui sont comprises. Un second paramètre orthogonal au premier, défini comme le contexte du locuteur, s'avère déterminant lorsqu'il s'agit d'aborder la réalisation concrète des communications interpersonnelles réussies. La déclinaison de ces deux paramètres dans le cadre de la messagerie électronique nous conduit à concevoir la notion de correspondance. Cette dernière constitue une généralisation du courrier électronique dont la mise en oeuvre offre une condition suffisante de qualification des échanges réussis, via ce média. Une correspondance permet de prendre en compte pour chaque message, l'intention de communication et le contexte de son émetteur. Sa mise en oeuvre impose l'application en certains points du réseau, de politiques spécifiques au domaine administratif de référence, qui prennent en argument l'intention de communication et le contexte courant de l'émetteur. Un second bénéfice apporté par ce concept concerne le niveau de personnalisation du service de messagerie qui atteint une granularité de finesse maximale, du fait qu'il peut s'appliquer de façon différenciée, à chaque occurrence de message. Ces travaux ont abouti à la description d'une architecture représentative accompagnée de la définition de trois extensions de standards existants (SUBMISSION, IMF et S/MIME). Notre approche a été illustrée à travers deux cas d'usages importants, conformes à des spécifications recommandées pour les domaines administratif (RGS- référentiel général de sécurité) et militaire (MMHS - Military Message Handling System)

A correspondence model for a future military messaging handling system

International audienceMessaging service still remains fundamental for military operations. This service is an important tool to fulfill missions, either in time of peace or in time of crisis. Military operational needs must comply with specific requirements. Military standards describe the services that meet these needs. For different reasons, current military messaging standards have become obsolete, thus demanding the definition of new military standards. The main requirements concerning such systems have been put together. The main document, "Future Military Messaging," issued in 2005, identifies the different usages of a future military messaging system with the associated requirements in each case. Even if this document has become the reference model in the military messaging area, new theoretical developments are required. Indeed, it quickly appears that the development of a messaging system compliant only with this model could lead to rigid implementation, preventing any evolution of the system. This article reformulates the messaging system through a new concept called correspondence applied to military messaging. The main interest of this model is to decorrelate the deployment of the policies from the implementation of the messaging handling system. Therefore, it offers new prospects for military messaging systems with the ability of providing different levels of services dedicated to various military environments

An Interoperable Zero Trust Federated Architecture for Tactical Systems

International audienceIn military and tactical missions, operational needs can require different domains and nations in a coalition to federate, to facilitate sharing of resource between domains. On the other hand, data and services need to be protected against unauthorized access. The zero trust paradigm provides principles for securing data and services, based on fine-grain compartmentalization of resources and least-privileged access policies. In zero trust architectures, every access to a resource is verified, without relying on implicit trust between the requester and the resource. However, state-of-the-art federation procedures weaken the zero trust security guarantees, as information on requesters, belonging to one domain, cannot be verified by another domain offering a resource. Therefore, access inherently relies on trust between domains, which contradicts zero trust principles. This paper presents a novel technique to create a zero trust federation, in which every access to a resource is explicitly verified, without trusting federation partners. In particular, due to the power constraints on devices composing tactical architectures, the presented solution does not require invasive software to be installed in requester devices

A confident email system based on a new Correspondence Model

International audienceDespite all the current controversies, the success of the email service is still valid. The ease of use of its various features contributed to its widespread adoption. Ingeneral, the email system provides for all its users the same set of features controlled by a single monolithic policy. Such solutions are efficient but limited because they grant no place for the concept of usage which denotes a user's intention of communication: private, professional, administrative, official, military.... The ability to efficiently send emails from mobile devices creates new interesting opportunities. We argue that the context (location, time, device, operating system, access network…) of the email sender appears as a new dimension we have to take into account to complete the picture. Context is clearly orthogonal to usage because a same usage may require different featuresdepending of the context. It is clear that there is no global policy meeting requirements of all possible usages and contexts. To address this problem, we propose to define a correspondence model which for a given usage and context allows to derive a correspondence type encapsulating the exact set of required features. With this model, it becomes possible to define an advanced email system which may cope with multiple policies instead of a single monolithic one. By allowing a user to select the exact policy coping with her needs, we argue that our approach reduces the risk-taking allowing the email system to slide from a trusted one to a confident one

Building a Confident Advanced Email System using a new Correspondence Model

International audienceDue to its ease of use combined with its efficiency, traditional email service constitutes one of the main success story brought by the Internet. Its popularity hides however significant gaps. Professional email systems usually remedy such deficiencies by compiling a lot of sophisticated features in a single monolithic policy which should ideally take into account security requirements together with various other specific needs. The main drawback of these approaches lies in their inherent rigidity. They indeed grant no place for the concepts of usage and context which are fundamental for any modern communication service. The usage is determined by a user's intention of communication: private, professional, administrative, official, military... Context is clearly orthogonal to usage because a same usagemay require different features depending of the context. We propose to define a correspondence model which for a given usage and context allows to dynamically derive a correspondence type encapsulating the exact set of required features. With this model, it becomes possible to define an advanced email system which may dynamically cope with multiple policies instead of a single monolithic one. By allowing a user to select the exact policy matching her needs, we argue that our approach reduces her risk-taking, providing in this way a confident advanced email system

Application of stereovision to the mechanical characterisation of ceramic refractories reinforced with metallic fibres

International audienceOptical methods that yield displacement or strain fields are now emerging significantly in the mechanical sciences. At the Research Center on Tools, Materials and Forming Processes (CROMeP) at Ecole des Mines d'Albi, a binocular stereovision system has been developed that can be used to measure: (a) the three-dimensional (3D) shape of a static object, or (b) the surface strains of an object undergoing some 3D mechanical or thermal stress. In this paper, the application of the stereovision technique to investigate the behaviour of ceramic refractories reinforced with metallic fibres is presented: (i) after the rupture of the sample for assessing the 3D orientation of the fibres in order to correlate a micro-mechanical model of fibre pullout with the macro-mechanical results of tensile tests, and (ii) during a tensile test for measuring the 3D displacement/strain field around a notch

Characterization of the EM66 Biomarker in the Pituitary and Plasma of Healthy Subjects With Different Gonadotroph Status and Patients With Gonadotroph Tumor

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Preservation of historical buildings: understanding of corrosion mechanisms of metallic rebars in concrete

International audienceNumerous monuments of the 20th century made of reinforced concrete are decaying due to the corrosion of their metallic reinforcements, the growth of the corrosion products generally inducing spalling. In order to prevent these degradations before the concrete cracks, it would be interesting to determine by non destructive methods the state of corrosion of the embedded rebars. Three types of corrosion forms have been evidenced on samples collected on three monuments: first is original and contains wüstite, the second is a mixture of the first and thicker layers containing oxy-hydroxides, characteristic of the third typ

Corrosion of rebars embedded in ancient concrete: correlation between on site testing and corrosion products identification

International audienceSeveral hundreds of buildings made of reinforced concrete are now classified as historical in France. Their major pathology is carbonation induced corrosion. The cracking and spalling decays induced by this natural aging process cause loss of material incompatible with the deontology of historical monuments conservation. Therefore it is crucial to understand the corrosion process of embedded steel and to be able to evaluate precisely the corrosion activity on site, in order to predict and may-be to prevent such decays. Current on site non destructive tools for diagnosis operations are potential mapping or corrosion rate measurements. But, such electrochemical techniques are clearly season influenced. Moreover, corrosion rates induced by carbonation are often very low and therefore can be difficult to measure. As a consequence, in areas heavily affected by spalling phenomena, low corrosion activity is often evidenced, so that the interpretation of the results can be problematic. A last hypothesis could be that the oxide layer formed is so resistive that the conductivity necessary for the measurement is lost. In order to better understand the corrosion process of rebars embedded in carbonated concrete, and may be to improve the reliability of those diagnosis tools, it seemed interesting to try to correlate on site measurements with the identification of corrosion patterns. Therefore, on a 56 years old industrial building (Air Purifier of the Meudon Wind tunnel), several sets of potential mapping, resistivity and corrosion rate measurements were performed, respectively in winter time and in spring time, and after medium or heavy moistening. Then reinforced concrete cores were sampled both in supposed active and passive corrosion areas, in order to evaluate the carbonation depth and to identify the corrosion patterns