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International audience; With the ever advancing expansion of the Internet of Things (IoT) into our everyday lives, the number of attack possibilities increases. Furthermore, with the incorporation of the IoT into Critical Infrastructure (CI) hardware and applications, the protection of not only the systems but the citizens themselves has become paramount. To do so, specialists must be able to gain a foothold in the ongoing cyber attack war-zone. By organising the various attacks against their systems, these specialists can not only gain a quick overview of what they might expect but also gain knowledge into the specifications of the attacks based on the categorisation method used. This paper presents a glimpse into the area of IoT Critical Infrastructure security as well as an overview and analysis of attack categorisation methodologies in the context of wireless IoT-based Critical Infrastructure applications. We believe this can be a guide to aid further researchers in their choice of adapted categorisation approaches. Indeed, adapting appropriated categorisation leads to a quicker attack detection, identification, and recovery. It is, thus, paramount to have a clear vision of the threat landscapes of a specific system.

International audience; Flooding is frequent on the Nantes ring road and disrupts users dependent on this mode of transport directly or indirectly. To deal with them, the road operator has defined preventive and curative measures based essentially on the flow of the river involved in the submergence of the roadway. The RESIIST (Resilience of Interconnected Infrastructures and Systems) research project aims to develop a methodology and tools to assess the resilience of Critical Infrastructures (within the meaning of European Directive 2008/114/EC), of which we find the ring road. In order to test them, a scenario will be used to simulate the events likely to cause flooding, characterise the disturbances caused by these events and the interactions with adjacent road infrastructures and present a decision aidingbased on the road operator's criteria. RESIIST can contribute to improving the resilience of critical infrastructures by enabling stakeholders to continuously monitor data from the context, to interpret them and deduce the disruption’s risks on infrastructure and territory and finally to benefit from proposals for solutions adapted and corresponding to their decision criteria. More modestly, this scenario could serve as a support in discussions on possible work concerning the ring road and the crisis management protocols.

Over the last 15 years, particular attention has been paid to the protection and security of so-called critical infrastructures, including drinking water distribution networks (WDN). Infrastructure managers are seeking to ensure their security and improve their resilience. However, the question of the economic efficiency and of the economic benefits provided by such measures remains open. The purpose of this article is to contribute to this debate. It presents the results of a Choice Experiment survey aimed at estimating the benefits of measures to protect against a potential cyberattack in the territory of Eurométropole de Strasbourg in France. The aggregate benefits of two resilience programs are assessed. They help make ‘optimal’ and informed decisions from a cost–benefit perspective.

12th International Conference on Risk Analysis and Hazard Mitigation, LISBONNE, Portugal, 23-/05/2020 - 25/05/2020; Maintenance and protection of road infrastructures (RI) against multi-hazard events requires the use of risk assessment to identify threats, to assess vulnerabilities and to evaluate the impact on infrastructure systems according to the probability of occurrence of such threats. Dealing with a complex network system, such as RI, demands the improvement of risk assessment approach by resorting to the concept of resilient infrastructure, capable of dealing with scenarios linked to disastrous events with the aim of minimizing service interruptions and quickly recovering. In this paper, the network analysis of a RI case study is addressed to obtain a qualitative measure of resilience related to travel patterns of road network. The topology of RI system, a pattern of connections according to graph theory, between components interacting jointly to provide the required functionalities, is supplied by road network data from OpenStreetMap. Then a probabilistic system model is used to define a non-degradated condition and the scenarios of failure events that can affect the network system. For each condition, the evaluation of the related shortest paths, as a measure of the network system performance, provide the qualitative resilience measurement identifying performance criteria or levels of service requirements. The proposed assessment through transport network measures can find application in risk assessment and management by RI owners and managers.

International audience; Considerable attention has been paid to the vulnerability of critical infrastructures, because of the increasing occurrence of disruptive events, such as man-made or natural disasters. Even small disruptions could eventually affect the normal function of infrastructure systems. Enhancing the reliability of these systems and their robustness to disruptions is necessary and urgent. High-speed rail is a critical infrastructure that is subject to various disruptions, including component aging, malicious attacks, natural disasters, demand surges. In this study, we analyze the topological centrality indicators of China Railway High-speed (CRH) network using network theory, and take real train flow information for assessing the importance of network components in terms of vulnerability to disruption. By Monte Carlo simulation, we analyze the risk of the CRH network under random attacks and spatially localized failures. The significance of taking pre-actions for protecting critical infrastructures by mitigating its vulnerability to disruptions is emphasized.

International audience; This article proposes a novel mathematical optimization framework for the identification of the vulnerabilities of electric power infrastructure systems (which is a paramount example of critical infrastructure) due to natural hazards. In this framework, the potential impacts of a specific natural hazard on an infrastructure are first evaluated in terms of failure and recovery probabilities of system components. Then, these are fed into a bi‐level attacker–defender interdiction model to determine the critical components whose failures lead to the largest system functionality loss. The proposed framework bridges the gap between the difficulties of accurately predicting the hazard information in classical probability‐based analyses and the over conservatism of the pure attacker–defender interdiction models. Mathematically, the proposed model configures a bi‐level max‐min mixed integer linear programming (MILP) that is challenging to solve. For its solution, the problem is casted into an equivalent one‐level MILP that can be solved by efficient global solvers. The approach is applied to a case study concerning the vulnerability identification of the georeferenced RTS24 test system under simulated wind storms. The numerical results demonstrate the effectiveness of the proposed framework for identifying critical locations under multiple hazard events and, thus, for providing a useful tool to help decisionmakers in making more‐informed prehazard preparation decisions.

Critical infrastructures (CIs) provide essential goods and service for modern society. Their safety and reliability are primary concerns. The complexity of CIs calls for approaches of system analysis capable of viewing the problem from multiple perspectives. The focus of the present thesis is on the integration of the control perspective into the safety and reliability analysis of CIs. The integration is first approached by investigating the control properties of a small network system, i.e., an electric power microgrid. A simulation-based scheme is developed for the analysis from different perspectives: supply service, controllability and topology. An optimization-based model predictive control framework is proposed to analyze the microgrid under various failure scenarios. Then, a multi-perspective framework is developed to analyze CIs with respect to supply service, controllability and topology. This framework enables identifying the role of the CI elements and quantifying the consequences of scenarios of multiple failures, with respect to the different perspectives considered. To demonstrate the analysis framework, a benchmark network representative of a real gas transmission network across several countries of the European Union (EU) is considered as case study. At last, a multi-objective optimization framework is proposed for complex CIs design: design of network topology and allocation of link capacities are performed in an optimal way to minimize the non-supplied demand and the structural complexity of the system, while at the same time to maximize the system controllability. Investigation on the multiple objectives considered is performed to retrieve useful insights for system design. The findings of this thesis demonstrate the importance of developing frameworks of analysis of CIs that allow considering different perspectives relevant for CIs design, operation and protection., Les infrastructures critiques (CIs) sont essentielles au fonctionnement de la société moderne. Leur sécurité et leur fiabilité sont les principales préoccupations. La complexité des CIs exige des approches d'analyse de système capables de voir le problème de plusieurs points de vue. La présente thèse porte sur l'intégration de la perspective de contrôle dans l'analyse de sécurité et de fiabilité des éléments de configuration. L'intégration est d'abord abordée par examiner les propriétés de contrôle d'un microgrid d'alimentation électrique. Un schéma basé sur la simulation est développé pour l'analyse sous différentes perspectives : le service d'approvisionnement, la contrôlabilité et la topologie. Un cadre basé sur la commande prédictive (MPC) est proposé pour analyser le microrgrid dans divers scenarios de défaillance. Ensuite, un cadre multi-perspectif est développé pour analyser les CIs considérant le service d'approvisionnement, la contrôlabilité et la topologie. Ce cadre permet d'identifier le rôle des éléments de CIs et de quantifier les conséquences de scénarios de défaillances, par rapport aux différents perspectives considérées. Afin de présenter le cadre d'analyse, un réseau de transport de gaz réel à travers plusieurs pays de l'Union européenne est considéré comme une étude de cas. En fin, un cadre d'optimisation a trois objectifs est proposé pour la conception de CI : la topologie du réseau et l'allocation des capacités de liaison sont optimisées minimisant la demande non fournie et la complexité structurelle du système, et en même temps maximisant la contrôlabilité du système. Une investigation approfondie sur les multiples objectifs considérés est effectuée pour tirer des informations utiles pour la conception du système. Les résultats de cette thèse démontrent l'importance de développer du cadre d'analyse des CIs considérant de plusieurs perspectives pertinentes pour la conception, l'opération et la protection des CIs.

International audience; With recent advances in systems-of-systems, reliability analysis becomes a very challenging research topic. One of the most pressing issues is to figure out a plan to handle resilience. On this basis, we propose, in this paper, a structural deterministic approach to quantitatively measure systems resilience. This approach is based on a three-step method. First, evaluate the functional dependencies between groups by considering a system-of-systems as a large-scale interconnected network of systems distributed into interdependent groups. This leads us to better understand the overall connections and process continuity. Next, analyse how much the global architecture of the system-of-systems depends on every group. Last, estimate its structural resilience by measuring the impact of each system's failure on the other systems forming the global system and building the process. Two case studies are provided to experiment our approach. The results are cross-compared and evaluated.

We address security issues in cyber-physical industrial systems. Attacks against these systems shall be handled both in terms of safety and security. Control technologies imposed by industrial standards already cover the safety dimension. From a security standpoint, the literature has shown that using only cyber information to handle the security of cyber-physical systems is not enough, since physical malicious actions are ignored. For this reason, cyber-physical systems have to be protected from threats to their cyber and physical layers. Some authors handle the attacks by using physical attestations of the underlying processes, f.i., physical watermarking to ensure the truthfulness of the process. However, these detectors work properly only if the adversaries do not have enough knowledge to mislead crosslayer data. This thesis focuses on the aforementioned limitations. It starts by testing the effectiveness of a stationary watermark-based fault detector, to detect, as well, malicious actions produced by adversaries. We show that the stationary watermark-based detector is unable to identify cyber-physical adversaries. We show that the approach only detects adversaries that do not attempt to get any knowledge about the system dynamics. We analyze the detection performance of the original design under the presence of adversaries that infer the system dynamics to evade detection. We revisit the original design, using a non-stationary watermark-based design, to handle those adversaries. We also propose a novel approach that combines control and communication strategies. We validate our solutions using numeric simulations and training cyber-physical testbeds; Nous abordons des problèmes de sécurité dans des systèmes cyber-physiques industriels. Les attaques contre ces systèmes doivent être traitées à la fois en matière de sûreté et de sécurité. Les technologies de contrôles imposés par les normes industrielles, couvrent déjà la sûreté. Cependant, du point de vue de la sécurité, la littérature a prouvé que l’utilisation de techniques cyber pour traiter la sécurité de ces systèmes n’est pas suffisante, car les actions physiques malveillantes seront ignorées. Pour cette raison, on a besoin de mécanismes pour protéger les deux couches à la fois. Certains auteurs ont traité des attaques de rejeu et d’intégrité en utilisant une attestation physique, p. ex., le tatouage des paramètres physiques du système. Néanmoins, ces détecteurs fonctionnent correctement uniquement si les adversaires n’ont pas assez de connaissances pour tromper les deux couches. Cette thèse porte sur les limites mentionnées ci-dessus. Nous commençons en testant l’efficacité d’un détecteur qui utilise une signature stationnaire afin de détecter des actions malveillantes. Nous montrons que ce détecteur est incapable d’identifier les adversaires cyber-physiques qui tentent de connaître la dynamique du système. Nous analysons son ratio de détection sous la présence de nouveaux adversaires capables de déduire la dynamique du système. Nous revisitons le design original, en utilisant une signature non stationnaire, afin de gérer les adversaires visant à échapper à la détection. Nous proposons également une nouvelle approche qui combine des stratégies de contrôle et de communication. Toutes les solutions son validées à l’aide de simulations et maquettes d’entraînement

International audience; This paper provides a method to calculate the impact of cyber attacks and security countermeasures in a multi-dimensional coordinate system. The method considers the simulation of services, attacks and countermeasures in at least one dimensional coordinate system, the projection of which originates geometrical instances (e.g., lines, squares, rectangles, hyper-cubes). Such instances are measured through geometrical operations (i.e., length, area, volume, hyper-volume), so that we determine the impact of complex attacks arriving on the system, as well as the impact of the implementation of single and/or multiple countermeasures selected to mitigate the effects of such detected attacks. As a result, we are able to measure the size of cyber events, which allows us to determine the mitigation level of the incidents, as well as, residual risks, and potential collateral damages. A case study of a critical infrastructure system is provided to show the applicability of the model

International audience; This paper presents the EU H2020 project Smart Mature Resilience, which takes advantage of the fact that many cities are committed to become increasingly resilient and have ongoing processes for urban resilience. Smart Mature Resilience develops resilience management guidelines based on a Resilience Maturity Model that engages a growing number of stakeholders and multi-level governance in order for cities to become vertebrae for society’s resilience backbone. In a dual approach, employing a systematic literature review of international resilience implementation approaches alongside group processes with experts, the Smart Mature Resilience project has developed a preliminary resilience maturity model consisting of five stages Starting, Moderate, Advanced, Robust and verTebrate (SMART) and a Systemic Risk Assessment Questionnaire. The SMART Resilience Maturity Model suggests two principal processes for the transition to resilience maturity: (1) A process of increasing engagement and collaboration with new stakeholder types, from local, to regional, to national to European in a growing resilience backbone, and (2) a process of quality improvement of policies for transitioning from a Safety-I to a Safety-II perspective (from risk assessment & mitigation to adaption to future surprises as conditions evolve).

International audience; Computer and information systems are now at the core of numerous critical infrastructures. However, their security management is by far not a trivial issue. Further, these systems, by their very nature, belong to the domain of complex systems, where system dynamics (SD) is an established method, which aims at modelling such systems, their analysis and understanding. Further, on this basis it enables simulation of various policies to properly manage complex systems. More precisely, through understanding of the basic elements of the whole mosaic and their interplay, proper incentives can be tested. And this is important, because proper incentives can lead to the desired patterns of behavior of such systems, which may often be counter-intuitive. Therefore this paper presents a novel approach by using SD for managing critical infrastructures (more precisely the internet) when it comes to security related incentives. Based on already developed archetypes it provides a template model that bridges these conceptual models with concrete models that are suited to particular environments, and enable quantitative simulations.

International audience; We address detection of attacks against cyber-physical systems. Cyber-physical systems are industrial control systems upgraded with novel computing, communication and interconnection capabilities. In this paper we reexamine the security of a detection scheme proposed by Mo and Sinopoli (2009) and Mo et al. (2015). The approach complements the use of Kalman filters and linear quadratic regulators, by adding an authentication watermark signal for the detection of integrity attacks. We show that the approach only detects cyber adversaries, i.e., attackers with the ability to eavesdrop information from the system, but that do not attempt to acquire any knowledge about the system model itself. The detector fails at covering cyber-physical adversaries, i.e., attackers that, in addition to the capabilities of the cyber adversary, are also able to infer the system model to evade the detection. We discuss an enhanced scheme, based on a multi-watermark authentication signal, that properly detects the two adversary models

The objective of this paper is to provide a systematic view on the problem of vulnerability and risk analysis of critical infrastructures. Reflections are made on the inherent complexities of these systems, related challenges are identified and possible ways forward for their analysis and management are indicated. Specifically: the framework of vulnerability and risk analysis is examined in relation to its application for the protection and resilience of critical infrastructures; it is argued that the complexity of these systems is a challenging characteristic, which calls for the integration of different modeling perspectives and new approaches of analysis; examples of are given in relation to the Internet and, particularly, the electric power grid, as representative of critical infrastructures and the associated complexity; the integration of different types of analyses and methods of system modeling is put forward for capturing the inherent structural and dynamic complexities of critical infrastructures and eventually evaluating their vulnerability and risk characteristics, so that decisions on protections and resilience actions can be taken with the required confidence.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]GEUSI; International audience; The vulnerability analysis of our societies to major disturbances is of outmost importance in the fields of Infrastructure Asset Management (IAM). Several methodologies have already been developed to assess the vulnerability of critical infrastructures (CIs). Supply networks (water, gas, energy…) are also critical infrastructures (called Critical Networks or CNs hereafter), and should be considered with specific care due to (a) their complexity and spatial extent, (b) their role in providing other CIs with resources. In a first part, we present our framework for vulnerability and resilience in the French-German project “ResiWater” (Innovative Secure sensor Networks and Model-based Assessment Tools for Increased Resilience of water Infrastructures), funded by ANR and BMBF. We will then illustrate the various approaches to vulnerabilities. Lastly, we will draw our conclusions, which will be the guidelines for our project.

In this paper, we evaluate the robustness and recovery of connected critical infrastructures (CIs) under a system-of-systems (SoS) framework taking into account: (1) the dependencies among the components of an individual CI and the interdependencies among different CIs; (2) the variability in component performance, by a multistate model; and (3) the epistemic uncertainty in the probabilities of transitions between different components states and in the mean values of the holding-times distributions, by means of intervals. We adopt the goal tree success tree–dynamic master logic diagram (GTST–DMLD) for system modeling and perform the quantitative assessment by Monte Carlo simulation. We illustrate the approach by way of a simplified case study consisting of two interdependent infrastructures (electric power system and gas network) and a supervisory control and data acquisition (SCADA) system connected to the gas network. This article is available in the ASME Digital Collection at http://dx.doi.org/10.1115/...

Too many dramatic events occurred over the last ten years have demonstrated the severity and extent of impacts that territories may be confronted with. Damages to critical infrastructures may have a variety of downfall disturbing effects, which can lead territories and society into a huge crisis. Interdependency between these essential activities on the one hand, and between these activities and the population on the other hand, increases their vulnerability. This thesis presents a methodology to better assess direct and indirect impacts of a major disturbance. The issue is addressed from a multi-activity perspective, to take into account territories complexity.In the first stage, a territory is modeled using existing interdependency links between essential activities and the population. The methodology then identifies, based on a defined initial event, possible propagation scenarios and their consequences on services “users”. Finally, this simulation gives an assessment of the territory stakes resilience. This works provides a decision-making tool for the development of activity continuity plans, or risk assessment and mitigation policies., De trop nombreux évènements survenus la décennie passée illustrent la gravité et l’étendue des impacts auxquels les territoires peuvent être confrontés. L'atteinte aux infrastructures critiques peut induire de très nombreux dysfonctionnements en cascade pouvant plonger ce territoire et sa société dans une crise de grande ampleur. Les interdépendances entre ces activités essentielles et celles avec la population accentuent leur fragilité. Afin d'évaluer les impacts directs et indirects d'une perturbation majeure, la méthodologie développée étudie la problématique sous un angle multisectoriel répondant ainsi à une prise en compte de la complexité des territoires. Dans un premier temps, le territoire via ses activités essentielles et sa population est modélisé en s'appuyant sur les liens d'interdépendance existants. Sur la base d'un évènement initial donné, la méthode identifie les scénarios de propagation possibles et leurs conséquences sur les "usagers" concernés par la délivrance des services touchés. Cette simulation permet ainsi d'apprécier la résilience systémique des enjeux du territoire. Basé sur une approche systémique et spatiale, ce travail a pour objectif de fournir une aide à la décision à la planification des mesures de continuité et de rétablissement d'activité ou à la mise en place de mesures de traitement des risques.

International audience; The massive use of information and communication technologies in supervisory control and data acquisition (SCADA) systems opens new ways for carrying out cyberattacks against critical infrastructures relying on SCADA networks. The various vulnerabilities in these systems and the heterogeneity of cyberattacks make the task extremely difficult for traditional intrusion detection systems (IDS). Modeling cyberattacks has become nearly impossible and their potential consequences may be very severe. The primary objective of this work is to detect malicious intrusions once they have already bypassed traditional IDS and firewalls. This paper investigates the use of machine learning for intrusion detection in SCADA systems using one-class classification algorithms. Two approaches of one-class classification are investigated: 1) the support vector data description (SVDD); and 2) the kernel principle component analysis. The impact of the considered metric is examined in detail with the study of lp-norms in radial basis function (RBF) kernels. A heuristic is proposed to find an optimal choice of the bandwidth parameter in these kernels. Tests are conducted on real data with several types of cyberattacks.

International audience; In this paper, we look at the robustness of connected critical infrastructures under a systems-of-systems framework taking into account i) the dependencies and interdependencies among the components of a critical infrastructure and between different critical infrastructures, respectively; ii) the variability of the performance of each component by means of a multistate model; iii) the epistemic uncertainty in the transition probability between different components states by means of probability intervals. We adopt the Goal Tree Success Tree – Dynamic Master Logic Diagram for system modelling and we perform a quantitative assessment of the systems-of-systems performance by Monte Carlo simulation. We illustrate the approach by way of a simplified case study consisting of two interdependent infrastructures (electric power system and a gas network) and a supervisory control and data acquisition system connected to the gas network.

In view of the increasing use of Information and Communication Technol-ogies in power systems, it is essential to study the interdependencies between these coupled heterogeneous systems. This thesis focuses on the modeling of multi- infrastructure systems. This includes interdependencies and the three major failures families: common mode, escalat-ing and cascading. It is indeed necessary to identify the weaknesses that can trigger one or multiple failure(s) and cascade through these interdependent infrastructures, causing unex-pected and increasingly more serious failures to other infrastructures. In this context, different approaches, based on the theory of Complex Networks, are developed to identify the most critical components in the coupled heterogeneous system. One of the major scientific barriers addressed in this thesis is the development of a unified mathematical model to represent the behavior of multiple heterogeneous systems with complex asymmetrical communication patterns.; Au vu de l'utilisation croissante des technologies de l'information et de la communication dans les réseaux électriques, il est indispensable d'étudier l'étroite liaison entre ces infrastructures et d'avoir une vision intégrée du système couplé. Cette thèse porte ainsi sur la modélisation des systèmes multi-infrastructures. Cela inclut les interdépendances et les trajectoires de défaillances de type modes communs, aggravations et cascades. Il est en effet nécessaire d'identifier les points de faiblesse qui peuvent déclencher une ou de multiples défaillance(s), se succéder en cascade au travers de ces infrastructures liées et ainsi entrainer des défaillances inattendues et de plus en plus graves dans des autres infrastructures. Dans cette optique, différents modèles basés sur la théorie des Réseaux Complexes sont développés afin d'identifier les composants les plus importantes, et pourtant critiques, dans le système interconnecté. Un des principaux verrous scientifiques levé dans cette thèse est relatif au dé-veloppement d'un modèle mathématique " unifié " afin de représenter les comportements des multiples infrastructures non-homogènes qui ont des interdépendances asymétriques.

Part 2: Security Engineering; International audience; The Internet is now a critical infrastructure for the modern, information-based, e-Society. Stability and survivability of the Internet are thus important, especially in presence of catastrophic events which carry heavy societal and financial impacts. In this work, we analyze the stability of the inter-domain routing system during several large-scale catastrophic events that affected the connectivity of massive parts of the address space, with the objective of acquiring information about degradation of service and recovery capabilities.Results show that the Internet has maintained good responsiveness: service disruption has been contained and recovery times have been fast, even after catastrophic events. However, combining the view provided by the routing table and the view originated by the analysis of the BGP updates is not a trivial task, as such phenomena need to be analyzed at multiple time scales.

International audience; In this paper, we present ARMATURE, a peer-to-peer overlay that provides highly resilient communication service for critical infrastructure control. ARMATURE can encapsulate all control traffic, e.g. SCADA sessions, within secure and highly resilient transport tunnels. Herein, it does not rely on any particular ISP provisions and can use any available IP interface. Most importantly, the constructed overlay network is able to structurally reshape, i.e. to change its structural graph properties, to face different situations and to reunite otherwise conflicting service requirements. ARMATURE can be easily deployed in the current critical infrastructures to protect their monitoring and control communications.

International audience; Power Systems Reliability and Security highlight the need to identify and understand vulnerabilities that emerge from the interaction of two interdependent Critical Infrastructures: Information and Communication Technologies (ICT) and Power Systems. Modeling the physical, logical, cyber and geographical relations can give some information about the interactions between both infrastructures to enlighten their interdependencies and identify their mutual vulnerabilities. This paper presents a method, developed during the project SINARI, which adapts the theory of Complex Numbers to the theory of Complex Networks. The result of this symbiosis is a model that allows inherent vulnerabilities of coupled infrastructures to be identified. The method is demonstrated on a typical French Distribution Network including a surrounding ICT network.

In view of the increasing use of Information and Communication Technol-ogies in power systems, it is essential to study the interdependencies between these coupled heterogeneous systems. This thesis focuses on the modeling of multi- infrastructure systems. This includes interdependencies and the three major failures families: common mode, escalat-ing and cascading. It is indeed necessary to identify the weaknesses that can trigger one or multiple failure(s) and cascade through these interdependent infrastructures, causing unex-pected and increasingly more serious failures to other infrastructures. In this context, different approaches, based on the theory of Complex Networks, are developed to identify the most critical components in the coupled heterogeneous system. One of the major scientific barriers addressed in this thesis is the development of a unified mathematical model to represent the behavior of multiple heterogeneous systems with complex asymmetrical communication patterns., Au vu de l'utilisation croissante des technologies de l'information et de la communication dans les réseaux électriques, il est indispensable d'étudier l'étroite liaison entre ces infrastructures et d'avoir une vision intégrée du système couplé. Cette thèse porte ainsi sur la modélisation des systèmes multi-infrastructures. Cela inclut les interdépendances et les trajectoires de défaillances de type modes communs, aggravations et cascades. Il est en effet nécessaire d'identifier les points de faiblesse qui peuvent déclencher une ou de multiples défaillance(s), se succéder en cascade au travers de ces infrastructures liées et ainsi entrainer des défaillances inattendues et de plus en plus graves dans des autres infrastructures. Dans cette optique, différents modèles basés sur la théorie des Réseaux Complexes sont développés afin d'identifier les composants les plus importantes, et pourtant critiques, dans le système interconnecté. Un des principaux verrous scientifiques levé dans cette thèse est relatif au dé-veloppement d'un modèle mathématique " unifié " afin de représenter les comportements des multiples infrastructures non-homogènes qui ont des interdépendances asymétriques.

Technical networks can be considered as critical infrastructures and appear vulnerable to flooding. Well-functioning of these networks is a major issue for flood risk management and spatial planning. This research argues that networks resilience analysis is a necessary, but not sufficient, condition for improving urban resilience to flooding. In order to analyze networks resilience a methodology is proposed. This methodology requires analyzing resistance, absorption and recovery capacities of these networks. In this context, researches have been done about networks structural analysis, networks interdependencies analysis and networks restoration analysis. In fact, the methodology is mainly based on graph theory, safety methods, linear optimization and spatial analysis. Finally, to implement this methodology, a web-GIS has been designed. Thanks to this prototype, an application has been carried out for the city of Dublin., Les réseaux techniques sont des infrastructures critiques qui peuvent être vulnérables aux inondations. Leur bon fonctionnement représente donc un enjeu majeur pour la gestion des risques et des territoires. Cette recherche postule que l'analyse de la résilience des réseaux techniques constitue un préalable nécessaire, mais non suffisant, à la mise en place de politiques d'amélioration de la résilience urbaine face aux inondations. Une méthodologie d'analyse de la résilience des réseaux techniques est proposée. Elle requiert l'analyse des capacités de résistance, d'absorption et de récupération de ces réseaux. Dans ce cadre, des développements ont été réalisés afin d'analyser les propriétés structurelles des réseaux techniques, les interdépendances entre les réseaux techniques et la remise en service de ces réseaux. Ces développements reposent principalement sur la théorie des graphes, les méthodes issues de la Sûreté de Fonctionnement, l'optimisation linéaire et l'analyse spatiale. Enfin, un prototype web-SIG a été développé puis appliqué à la ville de Dublin.

Technical networks can be considered as critical infrastructures and appear vulnerable to flooding. Well-functioning of these networks is a major issue for flood risk management and spatial planning. This research argues that networks resilience analysis is a necessary, but not sufficient, condition for improving urban resilience to flooding. In order to analyze networks resilience a methodology is proposed. This methodology requires analyzing resistance, absorption and recovery capacities of these networks. In this context, researches have been done about networks structural analysis, networks interdependencies analysis and networks restoration analysis. In fact, the methodology is mainly based on graph theory, safety methods, linear optimization and spatial analysis. Finally, to implement this methodology, a web-GIS has been designed. Thanks to this prototype, an application has been carried out for the city of Dublin., Les réseaux techniques sont des infrastructures critiques qui peuvent être vulnérables aux inondations. Leur bon fonctionnement représente donc un enjeu majeur pour la gestion des risques et des territoires. Cette recherche postule que l'analyse de la résilience des réseaux techniques constitue un préalable nécessaire, mais non suffisant, à la mise en place de politiques d'amélioration de la résilience urbaine face aux inondations. Une méthodologie d'analyse de la résilience des réseaux techniques est proposée. Elle requiert l'analyse des capacités de résistance, d'absorption et de récupération de ces réseaux. Dans ce cadre, des développements ont été réalisés afin d'analyser les propriétés structurelles des réseaux techniques, les interdépendances entre les réseaux techniques et la remise en service de ces réseaux. Ces développements reposent principalement sur la théorie des graphes, les méthodes issues de la Sûreté de Fonctionnement, l'optimisation linéaire et l'analyse spatiale. Enfin, un prototype web-SIG a été développé puis appliqué à la ville de Dublin.

Part 2: Workshop; International audience; Risk management is coordinated activities to direct and control an organization with regard to risk, and includes the identification, analysis and mitigation of unacceptable risks. For critical infrastructures consisting of interdependent systems, risk analysis and mitigation is challenging because the overall risk picture can be strongly affected by changes in only a few of the systems. In order to continuously manage risks and maintain an adequate level of protection, there is a need to continuously maintain the validity of risk models while systems change and evolve. This paper presents a risk analysis tool that supports the modeling and analysis of changing and evolving risks. The tool supports the traceability of system changes to risk models, as well as the explicit modeling of the impact on the risk picture. The tool, as well as the underlying risk analysis method, is exemplified and validated in the domain of air traffic management.

International audience; Two applications of multi-objective genetic algorithms to the analysis and optimization of electrical transmission networks are reported to show the potential of these combinatorial optimization schemes in the treatment of highly interconnected, complex systems. In a first case study, an analysis of the topological structure of an electrical power transmission system in the literature is carried out to identify the most important groups of elements of different sizes in the network. The importance is quantified in terms of group closeness centrality. In the second case study, an optimization method is developed for identifying strategies of expansion of an electrical transmission network by addition of new lines of connection which are optimally identified with respect to the objective of improving the transmission reliability, while limiting the investment cost.

International audience; Infrastructure interdependency stems from the functional and logical relations among individual components in different distributed systems. To characterize the extent to which a contingency affecting an infrastructure is going to weaken, and possibly disrupt, the safe operation of an interconnected system, it is necessary to model the relations established through the connections linking the multiple components of the involved infrastructures. In this work, the modeling of interdependencies among network systems and of their effects on failure propagation is carried out within the simulation framework of a failure cascade process. The sensitivity of the critical loading value (the lower bound of the cascading failure region) and of the average cascade size with respect to the coupling parameters defining the interdependency strength is investigated as a means to arrive at the definition and prescription of cascade-safe operating margins.

To fully benefit from the progress of information and communication technologies, most critical infrastructures rely more and more on computer systems and have been progressively connected to the public networks like Internet. These interconnections result in complex interdependencies between infrastructures and expose these infrastructures to various computer and network vulnerabilities. In this thesis, we address issues of cascading failures reduction and the understanding of critical infrastructure interdependencies by developping software tools intended to topology generation and cascading failures simulation and detection. The algorithm defined by the topology generator is based on the euclidian distance and generates graphs representing several infrastructures with the same approach. Using similar approach to generate topologies for various infrastructures eases the interconnection and helps to represent the modelized interdependencies accurately. The cascading failure simulator is built with a modified epidemic model to take into account the main factors like routing protocols which are crucial for the failure propagation in the communication networks. The last contribution in this thesis describes a software developped with a client-server architecture. The proposed approach consists in reusing the existing supervison software to exchange information between network's stakeholders to detect cascading failure involving more than one infrastructure., Afin de profiter des progrès des technologies de l'information et de la communication, les infrastructures critiques se reposent de plus en plus sur des systèmes d'information complexes et se sont largement connectées à des réseaux publics, dont l'Internet. Ces interconnexions rendent les infrastructures interdépendantes et les exposent à l'ensemble des vulnérabilités des systèmes informatiques. Dans le cadre de cette thèse, nous proposons un ensemble d'outils de génération de topologies, de simulation des propagations des défaillances et de détection des pannes pour améliorer la compréhension de ces interdépendances et lutter contre les phénomènes de propagation des défaillances résultants. Le générateur de topologies proposé définit un algorithme de génération de graphes topologiques réalistes et adaptées aux études des interdépendances en générant plusieurs modèles d'infrastructure à partir d'une base commune, facilitant ainsi l'interconnexion des différents réseaux. Le simulateur des propagations des défaillances utilise les modèles épidémiologiques. Ces modèles ont été adaptés afin de prendre en compte les principaux facteurs qui influent les propagations des défaillances dans les réseaux de télécommunications comme les différents temporisateurs des protocoles de routage et la taille des tables de routage. Enfin, notre dernière contribution est la mise en œuvre d'un logiciel permettant de détecter des pannes dans un environnement hétérogène et distribué en réutilisant les outils de supervision existants. Cet outil offre des moyens pour assurer le contrôle d'accès aux informations lorsque l'environnement est constitué de plusieurs réseaux

International audience; This paper presents a reflection on how relevant it is to assess the vulnerability of the infrastructures on which people's daily mobility relies in order to understand, at an upper level, the territorial vulnerabilities. Once defined the concepts involved in this analysis and after a brief description of the research framework, the four steps thought process is detailed. The first step was to analyse people's daily mobility (motivation, trips volume, origin and destination) and the transportation system (offer and network) within the Metropolitan District of Quito (MDQ). This allowed pinpointing in a second step, key elements within road and transportation network referred to as critical infrastructures. The third step was to assess the critical infrastructure vulnerabilities which expose them to disturbances or failures. The fourth step was to identify all the areas which are liable to experiment a reduction of their accessibility due to a loss of critical infrastructures serviceability. This allowed assessing finally through scenarios the spatial backlashes which are likely to occur at the MDQ scale.; Cet article présente une réflexion sur l'intérêt d'interroger la vulnérabilité des supports physiques et logistiques des mobilités quotidiennes pour comprendre, à une échelle supérieure, les vulnérabilités territoriales. Après une définition des concepts mobilisés et une présentation du programme dans lequel cette recherche s'est inscrite, la démarche en quatre étapes est détaillée. La première étape a été d'analyser les déplacements quotidiens de personnes (motifs, volume, origine et destination) et le système de transport (offre et réseaux) dans le District Métropolitain de Quito (DMQ). Ceci nous a permis d'identifier et de localiser, dans une deuxième étape, les infrastructures-clefs, pièces maîtresses des réseaux routiers et de transport. La troisième étape a été d'évaluer les vulnérabilités de ces infrastructures-clefs, vulnérabilités qui les prédisposent aux endommagements, aux défaillances. La quatrième étape a été de comprendre les risques encourus par l'ensemble du territoire du DMQ compte tenu de la réduction possible de l'accessibilité de différents espaces attribuable à la perte d'opérationnalité d'infrastructures-clefs. Différents scénarios ont été envisagés mettant en perspective les répercussions spatiales prévisibles à l'échelle du DMQ.

International audience; Europe has recently faced several major industrial accidents generated by various causes. They have led to a lot of casualties and major damages to the environment (Enschede 2000, Toulouse 2001, Ath 2004...). Moreover, people have already stressed the influence of terrorism in the emergence of new risks. Geopolitical context has brought about risks wich cannot be completely avoided. It is illustrated by many events : Sarin Attack, Anthrax Letters, USS Cole and Limburg attacks, drinking water contamination, action on industrial sites... Regarding SEVESO establishments and similar critical infrastructures like ports and marshalling yards, these concerns are not included in the safety report required by the Authorities. In this paper, the authors establish, in the first part a brief inventory of the available methodologies and tools in order to elaborate a threat assessment. Then in the second part, they formulates some suggestions to integrate security aspects in a risk assessment, to globalise prevention and response approach in case of chemical accident or intentional act on chemical sites. An example of the adaptation of the ARAMIS methodology is explained in the last part.

International audience; This paper presents the main results of a research that aimed at analysing the risks to which the Metropolitan District of Quito is exposed considering the people’s mobility and areas accessibility issues. This analysis relies on a methodology implemented within the framework of a programme called “Information System and risks within the Metropolitan District of Quito” carried out by the French Development Research Institute (IRD) in partnership with the Municipality of Quito. The paper describes the main GIS processing used to (i) identify the critical transportation infrastructures, (ii) assess their vulnerability, (iii) measure the reduction of urban areas accessibility, and (iiii) evaluate the derived risks.; Ce texte présente les principaux résultats d’une recherche sur les risques encourus par le District Métropolitain de Quito menée selon une démarche qui privilégie les questions de mobilité des personnes et d’accessibilité des espaces. Cette analyse de risque ciblée sur les enjeux de la mobilité quotidienne repose sur une méthodologie mise au point dans le cadre du programme « Système d’information et risques dans le District Métropolitain de Quito » mené par l’Institut de Recherche pour le Développement (IRD) en partenariat avec la Mairie de Quito. L’article décrit les principaux traitements SIG utilisés pour (i) l’identification des enjeux de la mobilité, (ii) l’évaluation de leur vulnérabilité, (iii) la réduction de l’accessibilité, et (iiii) les risques encourus.