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Rabah, Mourad. "Évaluation de la sûreté de fonctionnement de systèmes multiprocesseurs à usage multiple". Toulouse, INPT, 2000. http://www.theses.fr/2000INPT021H.
Pełny tekst źródłaVache, Géraldine. "Evaluation quantitative de la sécurité informatique : approche par les vulnérabilités". Toulouse, INSA, 2009. http://eprint.insa-toulouse.fr/archive/00000356/.
Pełny tekst źródłaThis thesis presents a new approach for quantitative security evaluation for computer systems. The main objective of this work is to define and evaluate several quantitative measures. These measures are probabilistic and aim at quantifying the environment influence on the computer system security considering vulnerabilities. Initially, we identified the three factors that have a high influence on system state: 1) the vulnerability life cycle, 2) the attacker behaviour and 3) the administrator behaviour. We studied these three factors and their interdependencies and distinguished two main scenarios based on nature of vulnerability discovery, i. E. Malicious or non malicious. This step allowed us to identify the different states of the system considering the vulnerability exploitation process and to define four measures relating to the states of the system: vulnerable, exposed, compromised, patched and secure. To evaluate these measures, we modelled the process of system compromising by vulnerability exploitation. Afterwards, we characterized the vulnerability life cycle events quantitatively, using real data from a vulnerability database, in order to assign realistic values to the parameters of the models. The simulation of these models enabled to obtain the values of the four measures we had defined. Finally, we studied how to extend the modelling to consider several vulnerabilities. So, this approach allows the evaluation of measures quantifying the influences of several factors on the system security
Gadelrab, Mohammed El-Sayed Gadelrab. "Évaluation des systèmes de détection d'intrusion". Toulouse 3, 2008. http://thesesups.ups-tlse.fr/435/.
Pełny tekst źródłaThis thesis contributes to the improvement of intrusion detection system (IDS) evaluation. The work is motivated by two problems. First, the observed increase in the number and the complexity of attacks requires that IDSes evolve to stay capable of detecting new attack variations efficiently. Second, the large number of false alarms that are generated by current IDSes renders them ineffective or even useless. Test and evaluation mechanisms are necessary to determine the quality of detection of IDSes or of their detection algorithms. Unfortunately, there is currently no IDS evaluation method that would be unbiased and scientifically rigorous. During our study, we have noticed that current IDS evaluations suffer from three major weaknesses: 1) the lack of a rigorous methodology; 2) the use of non-representative test datasets; and 3) the use of incorrect metrics. From this perspective, we have introduced a rigorous approach covering most aspects of IDS evaluation. In the first place, we propose an evaluation methodology that allows carrying out the evaluation process in a systematic way. Secondly, in order to create representative test datasets, we have characterized attacks by classifying attack activities with respect to IDS-relevant manifestations or features. This allows not only to select attacks that will be included in the evaluation dataset but also to analyze the evaluation result with respect to attack classes rather than individual attack instances. Third, we have analyzed a large number of attack incidents and malware samples, such as viruses and worms. Thanks to this analysis, we built a model for the attack process that exhibits the dynamics of attack activities. This model allows us to generate a large number of realistic and diverse attack scenarios. The proposed methods have been experimented on two very different IDSes to show how general is our approach. The results show that the proposed approach allows overcoming the two main weaknesses of existing evaluations, i. E. , the lack of a rigorous methodology and the use of non-representative datasets. .
Martinello, Magnos. "Modélisation et évaluation de la disponibilité de services mis en oeuvre sur le web : une approche pragmatique". Toulouse, INPT, 2005. https://hal.science/tel-04595476.
Pełny tekst źródłaThis thesis presents a pragmatic modeling approach allowing designers of web-based applications and systems to evaluate the service availability provided to the users. Multiple sources of service unavailability are taken into account, in particular i) hardware and software failures affecting the servers, and ii) performance degradation (overload of servers, very long response time, etc. ). An hierarchical multi-level approach is proposed based on performability modeling, combining Markov chains and queueing models. The main concepts and the feasibility of this approach are illustrated using a web-based travel agency. Various analytical models and sensitivity studies are presented considering different assumptions with respect to the architectures, recovery strategies, faults, users profile and traffic characteristics
Kang, Eun-Young. "Abstractions booléennes pour la vérification des systèmes temps-réel". Thesis, Nancy 1, 2007. http://www.theses.fr/2007NAN10089/document.
Pełny tekst źródłaThis thesis provides an efficient formal scheme for the tool-supported real-time system verification by combination of abstraction-based deductive and model checking techniques in order to handle the limitations of the applied verification techniques. This method is based on IAR (Iterative Abstract Refinement) to compute finite state abstractions. Given a transition system and a finite set of predicates, this method determines a finite abstraction, where each state of the abstract state space is a true assignment to the abstraction predicates. A theorem prover can be used to verify that the finite abstract model is a correct abstraction of a given system by checking conformance between an abstract and a concrete model by establishing/proving that a set of verification conditions are obtained during the IAR procedure. Then the safety/liveness properties are checked over the abstract model. If the verification condition holds successfully, IAR terminates its procedure. Otherwise more analysis is applied to identify if the abstract model needs to be more precise by adding extra predicates. As abstraction form, we adopt a class of predicate diagrams and define a variant of predicate diagram PDT (Predicate Diagram for Timed systems) that can be used to verify real-time and parameterized systems
Varet, Antoine. "Conception, mise en oeuvre et évaluation d'un routeur embarqué pour l'avionique de nouvelle génération". Phd thesis, INSA de Toulouse, 2013. http://tel.archives-ouvertes.fr/tel-00932283.
Pełny tekst źródłaDacier, Marc. "Vers une évaluation quantitative de la sécurité informatique". Phd thesis, Institut National Polytechnique de Toulouse - INPT, 1994. http://tel.archives-ouvertes.fr/tel-00012022.
Pełny tekst źródłaLes modèles formels développés pour l'étude de la sécurité informatique, n'offrent pas le cadre mathématique désiré. L'auteur montre qu'ils adoptent une hypothèse de pire cas sur le comportement des utilisateurs, incompatible avec une modélisation réaliste. Après avoir montré, sur la base du modèle take-grant, comment s'affranchir de cette hypothèse, l'auteur définit un nouveau modèle, le graphe des privilèges, plus efficace pour gérer certains problèmes de protection. Il illustre son utilisation dans le cadre des systèmes Unix.
Enfin, l'auteur propose d'évaluer la sécurité en calculant le temps et l'effort nécessaires à un intrus pour violer les objectifs de protection. Il montre comment définir un cadre mathématique apte à représenter le système pour obtenir de telles mesures. Pour cela, le graphe des privilèges est transformé en un réseau de Petri stochastique et son graphe des marquages est dérivé. Les mesures sont calculées sur cette dernière structure et leurs propriétés mathématiques sont démontrées. L'auteur illustre l'utilité du modèle par quelques résultats issus d'un prototype développé afin d'étudier la sécurité opérationnelle d'un système Unix.
Duchene, Julien. "Développement et évaluation d'obfuscations de protocoles basées sur la spécification". Electronic Thesis or Diss., Toulouse, INSA, 2018. http://www.theses.fr/2018ISAT0054.
Pełny tekst źródłaThere are more and more protocols. Many of them have their specification available for interoperability purpose for instance. However, when it comes to intellectual property, this specification is kept secret. Attackers might use a wrongly implemented protocol to compromise a system, if he has access to the specification, it’s attack would be far more efficient. Even if he does not have access to the specification, he can reverse-engine it. Thus, create protocols hard to reverse is interesting. In this thesis, we develop a novel approach of protocol protections to make protocol reverse engineering more complex. We apply some obfuscations on protocol message format, furthermore, we do it automatically from the original protocol specification. Firstly, we have analyzed more than 30 different contributions of protocol reverse engineering tools. We retrieved the following elements : 1) Protocol reverse engineering tools try to infer regular models ; 2) They suppose that the parsing is done from left to right ; 3) They delimit fields based on well-known delimiters or with ad-hoc techniques ; 4) They cluster messages based on pattern similarity measures. Thus, to make protocol reverse harder, one can create protocols which does not respect theses statements. Secondly, we have proposed a model of message format on which obfuscations can be applied. With this model, we also provide some atomic obfuscations which can be composed. Each obfuscation target one or more protocol reverse engineering hypothesis. Obfuscation composition ensures effectiveness of our solution and makes protocol reverse-engineering more complex. This model is used to automatically generate code for parser, serializer and accessors. This solution is implemented into a framework we called ProtoObf. ProtoObf is used to evaluate obfuscations performance. Results show an increase of protocol complexity with the number of obfuscation composition while costs (particularly the serialized buffer size) stay low
Bennaceur, Mokhtar Walid. "Formal models for safety analysis of a Data Center system". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLV078/document.
Pełny tekst źródłaA Data Center (DC) is a building whose purpose is to host IT devices to provide different internet services. To ensure constant operation of these devices, energy is provided by the electrical system, and to keep them at a constant temperature, a cooling system is necessary. Each of these needs must be ensured continuously, because the consequence of breakdown of one of them leads to an unavailability of the whole DC system, and this can be fatal for a company.In our Knowledge, there exists no safety and performance studies’, taking into account the whole DC system with the different interactions between its sub-systems. The existing analysis studies are partial and focus only on one sub-system, sometimes two. The main objective of this thesis is to contribute to the safety analysis of a DC system. To achieve this purpose, we study, first, each DC sub-system (electrical, thermal and network) separately, in order to define their characteristics. Each DC sub-system is a production system and consists of combinations of components that transform entrance supplies (energy for the electrical system, air flow for the thermal one, and packets for the network one) into exits, which can be internet services. Currently the existing safety analysis methods for these kinds of systems are inadequate, because the safety analysis must take into account not only the internal state of each component, but also the different production flows circulating between components. In this thesis, we consider a new modeling methodology called Production Trees (PT) which allows modeling the relationship between the components of a system with a particular attention to the flows circulating between these components.The PT modeling technique allows dealing with one kind of flow at once. Thus its application on the electrical sub-system is suitable, because there is only one kind of flows (the electric current). However, when there are dependencies between sub-systems, as in thermal and network sub-systems, different kinds of flows need to be taken into account, making the application of the PT modeling technique inadequate. Therefore, we extend this technique to deal with dependencies between the different kinds of flows in the DC. Accordingly it is easy to assess the different safety indicators of the global DC system, taking into account the interactions between its sub-systems. Moreover we make some performance statistics. We validate the results of our approach by comparing them to those obtained by a simulation tool that we have implemented based on Queuing Network theory.So far, Production Trees models are not tool supported. Therefore we propose a solution method based on the Probability Distribution of Capacity (PDC) of flows circulating in the DC system. We implement also the PT model using the AltaRica 3.0 modeling language, and use its dedicated stochastic simulator to estimate the reliability indices of the system. This is very important to compare and validate the obtained results with our assessment method. In parallel, we develop a tool which implements the PT solution algorithm with an interactive graphical interface, which allows creating, editing and analyzing PT models. The tool allows also displaying the results, and generates an AltaRica code, which can be subsequently analyzed using the stochastic simulator of AltaRica 3.0 tool
Liu, Yi. "Security Assessment Against Side-Channel Attacks : Insights from an Information-Theoretic Perspective". Electronic Thesis or Diss., Institut polytechnique de Paris, 2023. http://www.theses.fr/2023IPPAT033.
Pełny tekst źródłaIn today's world, the widespread use of cryptographic devices highlights the need for their secure operation. Unintended leakages, like time, power, and electromagnetic emissions, can allow attackers to deduce secret keys via side-channel attacks (SCAs). Evaluating the security of cryptographic devices against SCAs is important for both the industrial and academic sectors, and information-theoretic metrics turn out to be effective tools. “Masking” stands out as a key countermeasure, with ongoing discussions on its optimization and the security of its implementations. In light of this context, the central aims of this thesis are to quantify side-channel leakage, appraise the security of cryptographic devices against SCAs (both unprotected and masked), and to explore methodologies for formulating more potent masking codes. For masking code construction, we establish linear programming bounds for the kissing number of q-ary linear codes, guided by recent findings on optimized code-based masking performance related to the dual code's kissing number. In addition, we demonstrate the connection between code-based masking efficacy and the whole weight enumeration of the dual of the masking code. The lexicographical order based on weight distribution prefixes is proposed for selecting ideal masking codes. Regarding side-channel leakage evaluation, we introduce a novel information metric, called conditional Sibson's alpha-information. This metric has an explicit expression and possesses several beneficial properties. Utilizing this metric, we delve into the sidechannel leakage of unprotected devices. Additionally, we use Fano's mutual information to evaluate the sidechannel leakage of code-based masked implementations under probing model. Lastly, when considering the security assessment of masked implementations, we utilize the alphainformation measure to appraise the security of both arithmetic and Boolean masking implementations. We derive universal bounds on the probability of success of any type of side-channel attack. These also provide lower bounds on the minimum number of queries required to achieve a given success rate
Piètre-Cambacédès, Ludovic. "Des relations entre sûreté et sécurité". Phd thesis, Télécom ParisTech, 2010. http://pastel.archives-ouvertes.fr/pastel-00570432.
Pełny tekst źródłaSrivastava, Brij Mohan Lal. "Anonymisation du locuteur : représentation, évaluation et garanties formelles". Thesis, Université de Lille (2018-2021), 2021. https://pepite-depot.univ-lille.fr/LIBRE/EDMADIS/2021/2021LILUB029.pdf.
Pełny tekst źródłaLarge-scale centralized storage of speech data poses severe privacy threats to the speakers. Indeed, the emergence and widespread usage of voice interfaces starting from telephone to mobile applications, and now digital assistants have enabled easier communication between the customers and the service providers. Massive speech data collection allows its users, for instance researchers, to develop tools for human convenience, like voice passwords for banking, personalized smart speakers, etc. However, centralized storage is vulnerable to cybersecurity threats which, when combined with advanced speech technologies like voice cloning, speaker recognition, and spoofing, may endow a malicious entity with the capability to re-identify speakers and breach their privacy by gaining access to their sensitive biometric characteristics, emotional states, personality attributes, pathological conditions, etc.Individuals and the members of civil society worldwide, and especially in Europe, are getting aware of this threat. With firm backing by the GDPR, several initiatives are being launched, including the publication of white papers and guidelines, to spread mass awareness and to regulate voice data so that the citizens' privacy is protected.This thesis is a timely effort to bolster such initiatives and propose solutions to remove the biometric identity of speakers from speech signals, thereby rendering them useless for re-identifying the speakers who spoke them.Besides the goal of protecting the speaker's identity from malicious access, this thesis aims to explore the solutions which do so without degrading the usefulness of speech.We present several anonymization schemes based on voice conversion methods to achieve this two-fold objective. The output of such schemes is a high-quality speech signal that is usable for publication and a variety of downstream tasks.All the schemes are subjected to a rigorous evaluation protocol which is one of the major contributions of this thesis.This protocol led to the finding that the previous approaches do not effectively protect the privacy and thereby directly inspired the VoicePrivacy initiative which is an effort to gather individuals, industry, and the scientific community to participate in building a robust anonymization scheme.We introduce a range of anonymization schemes under the purview of the VoicePrivacy initiative and empirically prove their superiority in terms of privacy protection and utility.Finally, we endeavor to remove the residual speaker identity from the anonymized speech signal using the techniques inspired by differential privacy. Such techniques provide provable analytical guarantees to the proposed anonymization schemes and open up promising perspectives for future research.In practice, the tools developed in this thesis are an essential component to build trust in any software ecosystem where voice data is stored, transmitted, processed, or published. They aim to help the organizations to comply with the rules mandated by civil governments and give a choice to individuals who wish to exercise their right to privacy
Jolly, Germain. "Evaluation d’applications de paiement sur carte à puce". Caen, 2016. https://hal.archives-ouvertes.fr/tel-01419220.
Pełny tekst źródłaThis thesis deals with high-level evaluation of applications in smartcards. The proposed method combines observation of the communication and detection of violated properties. The goal is to detect anomalies on smart cards (and more precisely on its implementation) and provide a better documentation on this error and on the reasons that triggered this error. We can know on the fly if an application has an error of implementation. The user of the tool configures a set of properties corresponding to the expected behavior of the application. To ascertain compliance of the behavior of the card application with the theory (specifications), the first step is the generation of the oracle, reference used during verification and validation activity. We quickly directed to a smarter technique to target the most interesting behaviors to check for our study. We worked on a generation method based on a genetic algorithm taking as input a set of transaction logs to automatically generate a set of properties (i. E. A set of local and expected behaviors of the applications). The evaluation methodology is developed through the WSCT framework. Two plugins were created and used to communicate with the smart card application, but also to observe and detect an abnormality in the behavior of the application. We used a JavaCard applet developed in the laboratory to test the feasibility of the method for two use cases: during the test phase, the methodology can be used in parallel by the certification firm and during the development of an application, for example, allowing improving the teaching of the JavaCard development and the evaluation of application
Lone, Sang Fernand. "Protection des systèmes informatiques contre les attaques par entrées-sorties". Phd thesis, INSA de Toulouse, 2012. http://tel.archives-ouvertes.fr/tel-00863020.
Pełny tekst źródłaChaudemar, Jean-Charles. "Étude des architectures de sécurité de systèmes autonomes : formalisation et évaluation en Event B". Thesis, Toulouse, ISAE, 2012. http://www.theses.fr/2012ESAE0003/document.
Pełny tekst źródłaThe study of complex system safety requires a rigorous design process. The context of this work is the formal modeling of fault tolerant autonomous control systems. The first objective has been to provide a formal specification of a generic layered architecture that covers all the main activities of control system and implement safety mechanisms. The second objective has been to provide tools and a method to qualitatively assess safety requirements. The formal framework of modeling and assessment relies on Event-B formalism. The proposed Event-B modeling is original because it takes into account exchanges and relations betweenarchitecture layers by means of refinement. Safety requirements are first specified with invariants and theorems. The meeting of these requirements depends on intrinsic properties described with axioms. The proofs that the concept of the proposed architecture meets the specified safety requirements were discharged with the proof tools of the Rodin platform. All the functional properties and the properties relating to fault tolerant mechanisms improve the relevance of the adopted Event-B modeling for safety analysis. Then, this approach isimplemented on a study case of ONERA UAV
Ciarletta, Laurent. "Contribution à l'évaluation des technologies de l'informatique ambiante". Nancy 1, 2002. http://www.theses.fr/2002NAN10234.
Pełny tekst źródłaComputer Science and Networks are more and more embedded into our daily life. Pervasive or Ubiquitous Computing is at the crossroad of four typical areas: Networking (connecting the elements), Personal Computing (providing services), Embedded Computing (improving software and hardware miniaturization), and Computer-Human Interaction (where artificial intelligence will provide the needed cleverness). This document introduces this emerging technology and the tools, architectures and methods that were developed during the course of my PhD: the Layered Pervasive Computing model, EXiST, the evaluation and distributed simulation platform and the VPSS security architecture. They are first steps towards the resolution of security, standardization, integration, and convergence issues of the technologies at play. Some prototypes and implementations, such as the Aroma Adapter (providing adhoc "intelligence" to electronic devices), a Smart conference Room and a version of EXiST working with Intelligent Agents, are also detailed
Girol, Guillaume. "Robust reachability and model counting for software security". Electronic Thesis or Diss., université Paris-Saclay, 2022. http://www.theses.fr/2022UPASG071.
Pełny tekst źródłaModern bug-finding techniques have become effective enough that the bottleneck is not finding bugs but finding the time to fix them. A popular way to address this problem is to focus first on bugs with a security impact, also known as vulnerabilities. This leads to the question of vulnerability assessment: could an attacker take advantage of a bug? In this thesis we attempt to assess one particular dimension contributing to the security impact of a bug: whether an attacker could trigger it reliably. We call this property replicability. Our goal is to formalize replicability to design bug-finding techniques which only report bugs which are replicable enough. We do so by considering a threat model where inputs to the program which the attacker can choose (like network inputs) are distinguished from inputs which the attacker does not control nor know (like entropy sources). We propose two approaches to replicability. Firstly, we define robust reachability, a qualitative property that expresses that a bug is not only reachable, but that when he chooses the right inputs, the attacker triggers the bug whatever the values of the program inputs he does not control. Secondly, we refine robust reachability quantitatively as the proportion of uncontrolled inputs that let the optimal attacker trigger the bug. We adapt symbolic execution to prove robust reachability and compute this proportion. Robust reachability is more coarse-grained because it is all-or-nothing but scales better than the quantitative approach. We illustrate in case studies the potential applications of these techniques, notably in terms of vulnerability assessment
Mekki, Mokhtar Amina. "Processus d'identification de propriétés de sécurité-innocuité vérifiables en ligne pour des systèmes autonomes critiques". Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1776/.
Pełny tekst źródłaRecent progress in the definition of decisional mechanisms has allowed computer-based systems to become more and more autonomous. For example, service robots can nowadays work in direct interaction with humans and carry out increasingly complex tasks. This transfer of responsibility poignantly raises the issue of system safety towards humans, the environment and the system itself. System surveillance by an independent safety monitor aims to enforce safe behaviour despite faults and uncertainties. Such a monitor must detect potentially dangerous situations in order to trigger safety actions aiming to bring the system towards a safe state. This thesis addresses the problem of identifying safety trigger conditions. A systematic process is proposed for the identification, starting from a HazOp/UML risk analysis. The proposed methodology also allows the identification of system states in which multiple safety actions might be executed concurrently, in order to be checked and, if necessary, corrected by a system expert. The methodology is applied to a robotic rollator
Landry, Simon. "Étude de la résistance des algorithmes cryptographiques symétriques face à la cryptanalyse moderne". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS287.
Pełny tekst źródłaThe goal of this thesis is to contribute to the state-of-the-art by proposing new areas of research in order to secure cryptographic algorithms within an embedded device.Our main focal axis is organized around the countermeasure called threshold implementations which is known to be resistant against side-channel analysis attacks in the presence of glitches.These latter phenomenon occur randomly within an electronic circuit and lead to numerous attacks in cryptanalysis. We study the application of threshold implementations on symmetric-key cryptography.In a first phase, we participate to the cryptographic litterature by designing new threshold implementations easily applicable on a large variety of symmetric-key algorithms. Our countermeasures are provable mathematically secured against side-channel analysis attacks in the presence of glitches. In comparison with the recent publications of the state-of-the-art, we adress new issues and we assure similar or better performances. Therefore, our research has resulted in two patents within STMicroelectronics, thereby contributing to the industrial innovation process.In a second phase, we are interested in the study of the symmetric-key algorithm SM4 and its resistance against side-channel analysis attacks. The works obtained allow to centralize the proposed SM4 countermeasures against side-channel analysis attacks of the state-of-the-art and offer a visibility on the software performances of these constructions. We finally introduce the first threshold implementation of the SM4 algorithm. Our construction is provably mathematically resistant against side-channel analysis attacks in the presence of glitches
Godefroy, Erwan. "Définition et évaluation d'un mécanisme de génération de règles de corrélation liées à l'environnement". Thesis, CentraleSupélec, 2016. http://www.theses.fr/2016SUPL0007/document.
Pełny tekst źródłaInformation systems produce continuously a large amount of messages and alerts. In order to manage this amount of data, correlation system are introduced to reduce the alerts number and produce high-level meta-alerts with relevant information for the administrators. However, it is usually difficult to write complete and correct correlation rules and to maintain them. This thesis describes a method to create correlation rules from an attack scenario specified in a high-level language. This method relies on a specific knowledge base that includes relevant information on the system such as nodes or the deployment of sensor. This process is composed of different steps that iteratively transform an attack tree into a correlation rule. The assessment of this work is divided in two aspects. First, we apply the method int the context of a use-case involving a small business system. The second aspect covers the influence of a faulty knowledge base on the generated rules and on the detection
Akrout, Rim. "Analyse de vulnérabilités et évaluation de systèmes de détection d'intrusions pour les applications Web". Phd thesis, INSA de Toulouse, 2012. http://tel.archives-ouvertes.fr/tel-00782565.
Pełny tekst źródłaBachy, Yann. "Sécurité des équipements grand public connectés à Internet : évaluation des liens de communication". Thesis, Toulouse, INSA, 2015. http://www.theses.fr/2015ISAT0014/document.
Pełny tekst źródłaToday, equipment embedding software and an Internet connection are more and more numerous and various. With the emergence of “the internet of things” and the trend to interconnect everything, many equipment used in our every day life are now connected to the internet: Smart-Tvs, DVD players, alarm and home automation systems, and even health assistance home devices, for example. Unfortunately, these technological evolutions also introduce new security threats. The massive use of internet facilitates the propagation of malware, capable of targeting any computer device, and more specifically any internet connected device. Although several methods allowing security analysis of industrial systems exist, their application to home devices is still limited. The existence and the criticality of potential vulnerabilities in these devices are not well-known, because they have not been thoroughly studied. This is precisely the objective of this thesis, which presents a method allowing to carry out a vulnerability analysis of internet connected home devices. This method is composed of two main phases: a risk analysis phasefollowed by an experimental phase. The security analysis of any type of equipement, requires a good knowledge ofits environment. In order to guide the evaluator in this task, we propose, as a first step, to rely on existing risk analysis methods. These methods are now mature, and allow the evaluator to obtain a global view of the risks incurred by the usage of anequipment. Then, during the second step of our method, the evaluator concentrates on the most important risks in order to demonstrate the technical feasibility of the scenarios leading to the considered risks, by carrying out several experiments.Considering the large amount and the diversity of I/Os on connected devices, it is important to focus on specifically rich attack scenarios, possibly depending on a simple local vulnerability. For this second step, an experimental method is proposedin order to study these attack scenarios, which, moreover, target equipement whose specifications are not necessarily available.In order to illustrate the entire method, this thesis presents two case studies: Integrated Access Devices and Smart-Tvs. These studies are carried out on a panel of devices from major internet service providers and TV manufacturers, allowing us to compare several devices available on the market. The vulnerabilities pointed out, mainly concern the communication means (local loop for the IAD, DVB-T interface for the smart-TVs) connecting these devices to their service providers (ISP for the IAD, TV and VoD for the smart-TVs). These communication links are usually considered safe, and have been, to our knowledge, seldom explored. Thisthesis thereby contributes to the security analysis of these particular communication means for connected devices and points out some original attack paths. Finally, this thesis ends by presenting different existing security mechanisms that can be used to avoid exploitation of the identified weaknesses
Mendy, Norbert Lucien. "Les attaques et la sécurité des systèmes informatiques". Paris 8, 2006. http://www.theses.fr/2006PA082735.
Pełny tekst źródłaHacking activities appeared around 1980 with first personal computers and since did not stop developing. At the beginning, this practice was primarily individual and playful. Now it is mainly made up by the activities of groups, with very various motivations. Today, due to the development of electronic means of communication, data security concerns a wider public. This thesis examines initially, from a technical and sociological point of view, attacks and defense mechanisms, and proposes a new concept of the security which is not only any centered on technical solutions but also takes in consideration the social dimension of the problem
Balduzzi, Marco. "Mesures automatisées de nouvelles menaces sur Internet". Paris, Télécom ParisTech, 2011. http://www.theses.fr/2011ENST0042.
Pełny tekst źródłaLn the last twenty years, the Internet has grown from a simple, small network to a complex, large-scale system. While the Internet was originally used to offer static content that was organized around simple websites, today, it provides both content and services (e. G. Chat, e-mail, web) as weil as the outsourcing of computation and applications (e. G. Cloud computing). Attackers are not indifferent to the evolution of the Internet. Often driven by a flourishing underground economy, attackers are constantly looking for vulnerabilities, misconfigurations and novel techniques to access protected and authorized systems, to steal private information, or to deliver malicious content. To date, not much research has been conducted to measure the importance and extent of these emerging Internet threats. Conventional detection techniques cannot easily scale to large scale installations, and novel methodologies are required to analyze and discover bugs and vulnerabilities in these complex systems. Ln this thesis, we advance the state-of-art in large scale testing and measurement of Internet threats. We research lnto three novel classes of security problems that affect Internet systems that experienced a fast surge in popularity (i. E. , ClickJacking, HTIP Parameter Pollution, and commercial cloud computing services that allow the outsourcing of server infrastructures). We introduce the tirst, large scale attempt to estimate the prevalence and relevance of these problems on the Internet
Kanoun, Wael. "Intelligent risk-aware system for activating and deactivating policy-based response". Télécom Bretagne, 2011. http://www.theses.fr/2011TELB0165.
Pełny tekst źródłaLa croissance de l'échelle des systèmes d'information critiques, combinée à l'augmentation continue de la fréquence et de la sophistication des attaques, rend les systèmes de réponses classiques inadéquats. Le système peut être la cible de plusieurs attaques simultanées, qui nécessitent l'activation de réponses différentes et contradictoires. En outre, une réponse peut avoir des effets collatéraux, comme (i) induire un coût intrinsèque sur le système, (ii) permettre et faciliter l'exécution d'autres attaques. Ainsi, les systèmes de réponse doivent être conçus d'une manière intelligente, pour optimiser l'activation des réponses appropriées, soit pour les automatiser, soit pour fournir une assistance à la décision aux administrateurs. Alors que la majorité des modèles de réponses existants considère seulement le coût des attaques et des réponses, nous adoptons une perspective plus générale basée sur le risque. Conformément à la définition du risque, nous considérons conjointement l'impact et la vraisemblance de succès des attaques en cours dans le processus de sélection de réponse. D'abord, nous proposons un workflow qui permet de réagir sur deux plans distincts, sur le plan tactique, et sur le plan stratégique. La réponse tactique est composée des contremesures élémentaires à portées limitées dans le système. Elles sont généralement liées à l'occurrence d'attaque en cours. En revanche, la réponse stratégique est spécifiée avec un langage formel qui permet d'exprimer des politiques de sécurité. Elles sont déployées globalement dans le système pour des menaces majeures. Ensuite, nous proposons un modèle pour la réponse tactique, basé sur une évaluation de risques dynamique. Quand une attaque en cours est détectée, nous évaluons le risque global en combinant l'impact potentiel avec la vraisemblance de succès de l'attaque. Les contremesures seront ordonnées par rapport à leur efficacité à réduire le risque global. Nous mettons l'accent sur le facteur de vraisemblance de succès, et nous proposons un modèle dynamique pour évaluer ce paramètre, en tenant compte du progrès de l'attaque en cours et l'état du système. Enfin, nous présentons un framework basé sur les risques pour l'activation et la désactivation de la réponse stratégique. Cette réponse est activée et déployée quand le risque de l'attaque en cours dépasse le coût cumulé de la réponse, et elle est maintenue tant que le risque reste présent. Contrairement aux systèmes existants, nous considérons la désactivation d'une réponse qui est effectuée lorsque le risque de l'attaque décroît, ou dés lors que le coût de la réponse devient important. Dans cette thèse, un service VoIP a été choisi pour valider nos propositions, tout en respectant les contraintes opérationnelles et de sécurité
Znaidi, Wassim. "Quelques propositions de solutions pour la sécurité des réseaux de capteurs sans fil". Lyon, INSA, 2010. http://theses.insa-lyon.fr/publication/2010ISAL0083/these.pdf.
Pełny tekst źródłaThe self-organized growth of three-dimensional (3D) quantum dots has attracted a lot of interest for their potential applications in ptoelectronic and in nanophotonic devices. In this work, we study by optical spectroscopy lnAs/lnP and lnAs/GaAs quantum dots grown by molecular beam epitaxy (MBE) using the Stanski-Krastanov (SK) growth mode. The quantum dots are then embedded in an electric-field tunable device called « nanopixel ». Ln the case of the lnAs/lnP quantum dots, we focused on the impact of growth conditions like the cap thickness of the double cap process on the emission energy, the influence of the first cap, temperature effect and the exciton-biexciton system. In the case of lnAs/GaAs system, we studied the impact of the capping layer, the excited level sates, the excitonbi-exciton system, and the impact of temperature. We successfully fabricated nanopixels including a quantum dots layer inside the intrinsic region of a Schottky diode. First results showing the effect of an electric field on a single quantum dot emission are finally described
Garcia-Alfaro, Joaquin. "Platform of intrusion management : design and implementation". Télécom Bretagne, 2006. http://www.theses.fr/2006TELB0025.
Pełny tekst źródłaAujourd’hui les systèmes informatiques sont plus vulnérables aux activités malveillantes qu’auparavant. C’est pour cela que l’utilisation des mécanismes de sécurité traditionnaux est encore nécessaire mais pas suffisante. Nous devons élaborer des méthodes efficaces de détection et de réponse aux attaques afin d’arrêter les événements détectés. Nous présentons dans cette thèse la conception d’une architecture générale qui agira en tant que point central pour analyser et vérifier des politiques de sécurité réseaux, et pour contrôler et configurer – sans anomalies ou erreurs de configuration – des composants de sécurité préventifs et de détection. Nous présentons également un mécanisme de réponse basé sur une bibliothèque de différents types de contremesures. L’objectif de ce mécanisme est d’aider l’administrateur à choisir dans cette bibliothèque la contremesure la mieux adaptée quand une intrusion est détectée. Nous finissons par la présentation d’une infrastructure pour la communication des composants de notre plateforme, et d’un mécanisme pour la protection des composants de celle-ci. Toutes les propositions et approches introduites dans cette thèse ont été implémentées et évaluées. Nous présentons les résultats obtenus dans les sections respectives de cette dissertation
Falcone, Yliès Carlo. "Etude et mise en oeuvre de techniques de validation à l'exécution". Université Joseph Fourier (Grenoble), 2009. http://www.theses.fr/2009GRE10239.
Pełny tekst źródłaThis thesis deals with three dynamic validation techniques: runtime verification (monitoring), runtime enforcement, and testing from property. We consider these approaches in the absence of complete behavioral specification of the system under scrutiny. Our study is done in the context of the Safety-Progress classification of properties. This framework offers several advantages for specifying properties on systems. We adapt the results on this classification, initially dedicated to infinite sequences, to take into account finite sequences. Those sequences may be considered as abstract representations of a system execution. Relying on this general framework, we study the applicability of dynamic validation methods. We characterize the classes of monitorable, enforceable, and testable properties. Then, we proposed three generic approaches for runtime verification, enforcement, and testing. We show how it is possible to obtain, from a property expressed in the {\SP} framework, some verification, enforcement, and testing mechanisms for the property under consideration. Finally, we propose the tools j-VETO and j-POST implementing all the aforementioned results on Java programs
Blond, Julien. "Modélisation et implantation d'une politique de sécurité d'un OS multi-niveaux via une traduction de FoCaLyze vers C". Paris 6, 2010. http://www.theses.fr/2010PA066370.
Pełny tekst źródłaContes, Arnaud. "Une architecture de sécurité hiérarchique, adaptable et dynamique pour la Grille". Nice, 2005. http://www.theses.fr/2005NICE4025.
Pełny tekst źródłaWhereas security is a key notion in the world of distributed applications, its numerous concepts are a difficult step to overcome when constructing such applications. Current middlewares provide all major security-related technologies. However developers still have to select the more accurate one and handle all its underlying processes which is particularly difficult with dynamic, grid-enabled applications. To facilitate the use of security concepts in such applications, tis thesis presents a decentralised security model which takes care of security requirements expressed by all actors (resource provides, administrators, users) involved in a computation. The model is implemented outside the application source code. Its configuration is read from external policy files allowing the adaptation of the application’s security according to its deployments. It has been conceived to handle specific behaviors which could happen during a distributed application life-cycle (use of newly discovered resources, remote object creation)
Thomas, Yohann. "Policy-based response to intrusions through context activation". Télécom Bretagne, 2007. http://www.theses.fr/2007TELB0057.
Pełny tekst źródłaNous présentons dans cette thèse une nouvelle approche de réponse face aux menaces auxquelles les systèmes informatiques sont soumis. Cette approche est basée sur l'intégration de la notion de contre-mesure au sein même de la politique de sécurité. En particulier, la notion de contexte permet d'évaluer l'état courant du système, et d'exprimer la politique en fonction de cet état. Pour ce faire, le modèle de contrôle d'accès basé sur l'organisation (Or-BAC) est utilisé, distinguant la définition générique de la politique de son implémentation effective en fonction du contexte. Le contexte intègre aussi bien des paramètres spatiaux et temporels que des paramètres plus proprement liés au domaine de la sécurité opérationnelle, comme les alertes remontées par les systèmes de détection d'intrusions (IDS). Ces alertes permettent la caractérisation de la menace à laquelle est soumis le système d'information à un instant donné. Des contextes de menace sont instanciés par notre système de réponse, permettant de déclencher des mises a jour de la politique et son déploiement subséquent. Ainsi, le système est capable d'adapter dynamiquement ses paramètres de fonctionnement en considérant notamment la menace. Nous proposons une approche innovante établissant le lien entre la politique de sécurité et l'un des principaux moyens qui permet d'encontrôler le respect, à savoir les systèmes de détection d'intrusions. Ce lien n'existait pas jusqu'alors, c'est-à-dire que les violations de la politique de sécurité détectées par les IDS n'avaient que peu de conséquences sur les exigences de la politique de sécurité effectivement implementées par les points d'application. Pourtant, force est de constater que l'implementation de la politique ne doit pas être statique. En particulier, nous montrons qu'il est possible de gérer dynamiquement l'accès aux services et aux ressources en fonction de la menace. En outre, ce travail fournit un début de réponse a la problématique de la réactivité et de la pertinence de la réponse face aux menaces. La réponse aux attaques informatiques est le plus souvent gérée manuellement par l'opérateur de sécurité. Ce même opérateur de sécurité manque malheureusement bien souvent de réactivité et de discernement pour répondre de manière adéquate à la menace, notamment parce qu'il est bien souvent noyé sous le flot des alertes ; le travail d'analyse est fastidieux et difficile au vu du nombre de paramètres a considérer. D'un autre côté, les attaques se multiplient, les attaquants mettent de moins en moins de temps a pénétrer les systèmes et à produire des dégâts qui peuvent rapidement se chiffrer en millions d'euros pour les entreprises. Automatiser la réponse est donc une nécessité
Disson, Eric. "Sécurité des accès dans les systèmes d'information coopératifs". Lyon 3, 2001. http://www.theses.fr/2001LYO33032.
Pełny tekst źródłaPham, Van-Hau. "De l'identification d'événements d'attaques dans des traces recueillies sur des pots de miel". Paris, Télécom ParisTech, 2009. http://www.theses.fr/2009ENST0017.
Pełny tekst źródłaLnternet security is a major issue nowadays. Several research initiatives have been carried out to understand the Internet security threats. Recently, a domain has emerged called attack attribution that aims at studying the modus operandi of the attacks and at identifying the characteristics of the groups responsible for the observed attacks. The work presented in this thesis participates to the efforts in this area. We show in this work that, starting from network traces collected over two years on a distributed system of low interaction honeypots, one can extract meaningful and useful knowledge about the attackers. To reach this goal, the thesis makes several important contributions. First of all, we show that attack traces can be automatically grouped into three distinct classes, corresponding to different attack phenomena. We have defined, implemented and validated algorithms to automatically group large amount of traces per category. Secondly, we show that, for two of these classes, so called micro and macro attack events can be identified that span a limited amount of time. These attack events represent a key element to help identifying specific activities that would, otherwise, be lost in the so called attack background radiation noise. Here too, a new framework has been defined, implemented and validated over 2 years of traces. Hundreds of significant attack events have been found in our traces. Last but not least, we showed that, by grouping attack events together, it was possible to highlight the modus operandi of the organizations responsible for the attacks. The experimental validation of our approach led to the identification of dozens of so called zombie armies. Their main characteristics are presented in the thesis and they reveal new insights on the dynamics of the attacks carried ou over the Internet
Briffaut, Jérémy. "Formation et garantie de propriétés de sécurité système : application à la détection d'intrusions". Orléans, 2007. http://www.theses.fr/2007ORLE2053.
Pełny tekst źródłaAbdelnur, Humberto Jorge. "Gestion de vulnérabilités voix sur IP". Thesis, Nancy 1, 2009. http://www.theses.fr/2009NAN10005/document.
Pełny tekst źródłaVoIP networks are in a major deployment phase and are becoming widely accepted due to their extended functionality and cost efficiency. Meanwhile, as VoIP traffic is transported over the Internet, it is the target of a range of attacks that can jeopardize its proper functionality. Assuring its security becomes crucial. Among the most dangerous threats to VoIP, failures and bugs in the software implementation will continue rank high on the list of vulnerabilities. This thesis provides three contributions towards improving software security. The first is a VoIP specific security assessment framework integrated with discovery actions, data management and security attacks allowing to perform VoIP specific assessment tests. The second contribution consists in an automated approach able to discriminate message signatures and build flexible and efficient passive fingerprinting systems able to identify the source entity of messages in the network. The third contribution addresses the issue of detecting vulnerabilities using a stateful fuzzer. It provides an automated attack approach capable to track the state context of a target device and we share essential practical experience gathered over a two years period in searching for vulnerabilities in the VoIP space
Benali, Fatiha. "Modélisation et classification automatique des informations de sécurité". Lyon, INSA, 2009. http://theses.insa-lyon.fr/publication/2009ISAL0007/these.pdf.
Pełny tekst źródłaThe security of the Information System(IS) has become an important strategic issue. Currently, organizations or companies are evolving and have multiple nodes running multiple systems. These organizations are deploying multiple security devices and offer different services to their users. Services, resources and equipment deployed may be the targets for intruders. Interoperability between products to monitoring the IS is absolutely necessary. We present in our work an architecture for intrusion detection system based on interoperability between different products (security and management) and services deployed in an organization. This architecture will provide a comprehensive and meets the current needs of the security administrator. Intrusion detection in this context is to analyze the information (alerts and events) generated from all these devices to prevent any action not legally permitted. The process of analyzing information security faced serious problems because of the heterogeneity of the mechanisms involved in the monitoring of the IS and because of the lack of standard to presents of such information. The thesis is part of the modeling of security information to address the problem of the heterogeneity of the products, allowing the management process of information security (such as intrusion detection or the search for causes of a security incident) to be operational and efficient. The first part of the thesis proposes a solution for modeling the semantics of information security through an ontology. The purpose of the ontology is to describe in a uniform manner the semantics for all activities that may be made by users of IS, regardless of the products involved in the supervision of an IS, and focusing on the concepts of knowledge for mechanisms for processing such information. The implementation of the ontology is to make a classification of events and alerts generated by the monitoring products, in categories that were described by the ontology. The second part of the thesis focuses on automating the classification of security messages. As we have a corpus of previously classified messages, therefore we are interested in the techniques for automatic categorization of text (CT). These techniques are based on machine learning methods. The proposed classification process consists of two stages. The first step allows the data preparation and representation in a format usable by the classification algorithms. The second step aims to implement the algorithms machine learning on information security preprocessed. The application of the solutions proposed in the thesis is on a basis of alerts and events provided by the company Exaprotect (a publisher of software security)
Hasrouny, Hamssa. "Gestion de confiance et solutions de sécurité pour les réseaux véhiculaires". Electronic Thesis or Diss., Evry, Institut national des télécommunications, 2018. http://www.theses.fr/2018TELE0001.
Pełny tekst źródłaVANETs (Vehicular Ad-hoc Networks) consist of vehicles capable of exchanging information by radio to improve road safety (alerts in case of accidents or in case of abnormal slowdowns, collaborative driving…) or allow internet access for passengers (collaborative networks, infotainment, etc.). Road safety messages exchanged between vehicles may be falsified or eliminated by malicious entities in order to cause accidents and endanger people life. In this thesis, we focus on defining, designing and evaluating a security solution for V2V communications in VANET, to ensure a secure communication and a good level of confidence between the different participating vehicles. Adopting a group-based model, we consider the Trustworthiness evaluation of vehicles participating in VANET and we develop a Trust Model to analyze the behavior of the vehicles in the group while preserving the privacy of the participants and maintaining low network overhead. We then propose a hierarchical and modular framework for Misbehavior Detection and Revocation Management
Sadde, Gérald. "Sécurité logicielle des systèmes informatiques : aspects pénaux et civils". Montpellier 1, 2003. http://www.theses.fr/2003MON10019.
Pełny tekst źródłaBascou, Jean-Jacques. "Contribution à la sécurité des systèmes : une méthodologie d'authentification adaptative". Toulouse 3, 1996. http://www.theses.fr/1996TOU30253.
Pełny tekst źródłaJacob, Grégoire. "Malware behavioral models : bridging abstract and operational virology". Rennes 1, 2009. http://www.theses.fr/2009REN1S204.
Pełny tekst źródłaCette thèse s'intéresse à la modélisation des comportements malicieux au sein des codes malveillants, communément appelés malwares. Les travaux de thèse s'articulent selon deux directions, l'une opérationnelle, l'autre théorique. L'objectif à terme est de combiner ces deux approches afin d'élaborer des méthodes de détection comportementales couvrant la majorité des malwares existants, tout en offrant des garanties formelles de sécurité contre ceux susceptibles d'apparaître. L'approche opérationnelle introduit un langage comportemental abstrait, décorrélé de l'implémentation. Le langage en lui-même repose sur le formalisme des grammaires attribuées permettant d'exprimer la sémantique des comportements. A l'intérieur du langage, plusieurs descriptions de comportements malicieux sont spécifiées afin de construire une méthode de détection multicouche basée sur le parsing. Sur la base de ce même langage, des techniques de mutation comportementale sont également formalisées à l'aide de techniques de compilation. Ces mutations se révèlent un outil intéressant pour l'évaluation de produits antivirus. L'approche théorique introduit un nouveau modèle viral formel, non plus basé sur les paradigmes fonctionnels, mais sur les algèbres de processus. Ce nouveau modèle permet la description de l'auto-réplication ainsi que d'autres comportements plus complexes, basés sur les interactions. Il supporte la redémonstration de résultats fondamentaux tels que l'indécidabilité de la détection et la prévention par isolation. En outre, le modèle supporte la formalisation de plusieurs techniques existantes de détection comportementale, permettant ainsi d'évaluer formellement leur résistance
Trabelsi, Slim. "Services spontanés sécurisés pour l'informatique diffuse". Phd thesis, Télécom ParisTech, 2008. http://pastel.archives-ouvertes.fr/pastel-00004140.
Pełny tekst źródłaFadlallah, Ahmad. "Des solutions pour la traçabilité des attaques Internet". Paris, ENST, 2008. http://www.theses.fr/2008ENST0012.
Pełny tekst źródłaThe Denial of Service (DoS) attacks are a real threat for the availability and stability of the Internet. Their continuous growth was the main motivation of our research, which starts with a thorough analysis of these attacks. The second step in our research was to study the existing DoS defense solutions. Our study provides an analysis of the most well known defense schemes, their advantages and limitations. In particular, we were interested in studying attack traceback solutions, given their important role in the framework of DoS defense. The analysis of different categories of traceback schemes led us to establish a number of requirements for an effective and deployable traceback solution. Our first solution proposes to mix two existing traceback techniques: packet marking and packet logging in order to mutually solve their problems. Our second solution tries to solve the storage overhead problem of the first solution. It is based on out-of-band signaling, which allows tracing IP flows through generating signaling messages. We enhance this solution by mixing the out of band signaling with packet marking. This method significantly reduces the bandwidth overhead of the previous solution while respecting the rest of performance, security and deployment requirements
Saadi, Rachid. "The Chameleon : un système de sécurité pour utilisateurs nomades en environnements pervasifs et collaboratifs". Lyon, INSA, 2009. http://theses.insa-lyon.fr/publication/2009ISAL0040/these.pdf.
Pełny tekst źródłaWhile the trust is easy to set up between the known participants of a communication, the evaluation of trust becomes a challenge when confronted with unknown environment. It is more likely to happen that the collaboration in the mobile environment will occur between totally unknown parties. An approach to handle this situation has long been to establish some third parties that certify the identities, roles and/or rights of both participants in a collaboration. In a completely decentralized environment, this option is not sufficient. To decide upon accesses one prefer to rely only on what is presented to him by the other party and by the trust it can establish, directly by knowing the other party or indirectly, and vice-versa. Hence a mobile user must for example present a set of certificates known in advance and the visited site may use these certificates to determine the trust he can have in this user and thus potentially allow an adapted access. In this schema the mobile user must know in advance where she wants to go and what she should present as identifications. This is difficult to achieve in a global environment. Moreover, the user likes to be able to have an evaluation of the site she is visiting to allow limited access to her resources. And finally, an user does not want to bother about the management of her security at fine grain while preserving her privacy. Ideally, the process should be automatized. Our work was lead to define the Chameleon architecture. Thus the nomadic users can behave as chameleons by taking the "colors" of their environments enriching their nomadic accesses. It relies on a new T2D trust model which is characterized by support for the disposition of trust. Each nomadic user is identified by a new morph certification model called X316. The X316 allows to carry out the trust evaluation together with the roles of the participants while allowing to hide some of its elements, preserving the privacy of its users
Razafindraibe, Hanitriniaina Mamitiana Alin. "Analyse et amélioration de la logique double rail pour la conception de circuits sécurisés". Montpellier 2, 2006. http://www.theses.fr/2006MON20117.
Pełny tekst źródłaMaingot, Vincent. "Conception sécurisée contre les attaques par fautes et par canaux cachés". Grenoble INPG, 2009. https://tel.archives-ouvertes.fr/tel-00399450.
Pełny tekst źródłaL'évolution des besoins en sécurité des applications grand public a entraîné la multiplication du nombre de systèmes sur puces doués de capacités de chiffrement. En parallèle, l'évolution des techniques de cryptanalyse permet d'attaquer les implantations des méthodes de chiffrement utilisées dans ces applications. Cette thèse porte sur le développement d'une méthodologie permettant l'évaluation de la robustesse apportée par des protections intégrées dans le circuit. Cette évaluation est basée d'une part sur l'utilisation de plates-formes laser pour étudier les types de fautes induits dans un prototype de circuit sécurisé ; et d'autre part, sur l'utilisation d'une méthode basée sur des simulations pendant la phase de conception pour comparer l'influence sur les canaux cachés de protections contre les fautes. Cette méthodologie a été utilisée dans un premier temps sur le cas simple d'un registre protégé par redondance d'information, puis sur des primitives cryptographiques telles qu'une S-Box AES et des co-processeurs AES et RSA. Ces deux études ont montré que l'ajout de capacités de détection ou de correction améliore la robustesse du circuit face aux différentes attaques
Mouelhi, Tejeddine. "Testing and modeling seurity mechanisms in web applications". Télécom Bretagne, 2010. http://www.theses.fr/2010TELB0151.
Pełny tekst źródłaThis thesis focuses on the issue of security testing of web-applications, considering the internal part of a system (access control policies) and then its interfaces (bypass testing and shielding). The proposed approaches led to address the issue of modeling the security policies as well as the testing artifacts, using Model-Driven Engineering as the underlying technology to propose elements for a model-driven security process. Concerning the internal part of a system, we first study the differences between classical functional tests and test targeting the security mechanisms explicitly (so called security tests). In this context, we adapted mutation analysis to assess and qualify security tests. Then, we proposed three complementary approaches dealing with access control testing; the first one is based on pair-wise technique and allows access control tests to be generated automatically, while the second approach allows functional tests to be selected and transformed into security tests. Finally, the last approach focuses on detecting hidden access control mechanisms, which harm the flexibility of the access control mechanisms and their ability to evolve. To complete all these approaches which focus on the internal part of the application, we tackled the issue of testing the interface and especially the bypass-testing. We leveraged the ideas of bypass-testing and used automated analysis of the web application to provide a new approach for testing and shielding web applications against bypass-attacks, which occur when malicious users bypass client-side input validation. The work on access control testing led us to focus on proposing new model-driven approaches for developing and integrating access control mechanisms in a way that guarantees better quality and testability. Two research directions were explored for this purpose. The first one is based on a metamodel and provides a complete MDE process for automatically specifying, and integrating (semi-automatically) access control policies. This approach takes into account testing at the early stage of modeling and provides a generic certification process based on mutation. Finally, the second approach is based on model composition and allows an automated integration of the access control policy, and more importantly the automated reconfiguration of the system when the access control policy needs to evolve
Kheir, Nizar. "Response policies and counter-measure : management of service dependencies and intrusion and reaction impacts". Télécom Bretagne, 2010. http://www.theses.fr/2010TELB0162.
Pełny tekst źródłaSaleh, Hayder. "Une architecture novatrice de sécurité à base de carte à puce Internet". Versailles-St Quentin en Yvelines, 2002. http://www.theses.fr/2002VERSA009.
Pełny tekst źródłaAbbes, Tarek. "Classification du trafic et optimisation des règles de filtrage pour la détection d'intrusions". Nancy 1, 2004. http://www.theses.fr/2004NAN10192.
Pełny tekst źródłaIn this dissertation we are interested by some bottlenecks that the intrusion detection faces, namely the high load traffic, the evasion techniques and the false alerts generation. In order to ensure the supervision of overloaded networks, we classify the traffic using Intrusion Detection Systems (IDS) characteristics and network security policies. Therefore each IDS supervises less IP traffic and uses less detection rules (with respect to traffics it analyses). In addition we reduce the packets time processing by a wise attack detection rules application. During this analysis we rely on a fly pattern matching strategy of several attack signatures. Thus we avoid the traffic reassembly previously used to deceive evasion techniques. Besides, we employ the protocol analysis with decision tree in order to accelerate the intrusion detection and reduce the number of false positives noticed when using a raw pattern matching method
Martinelli, Jean. "Protection d'algorithmes de chiffrement par blocs contre les attaques par canaux auxiliaires d'ordre supérieur". Versailles-St Quentin en Yvelines, 2011. http://www.theses.fr/2011VERS0043.
Pełny tekst źródłaTraditionally, a cryptographic algorithm is estimated through its resistance to "logical" attacks. When this algorithm is implanted within a material device, physical leakage can be observed during the computation and can be analyzed by an attacker in order to mount "side channel" attacks. The most studied side channel attack is the differential power analysis (DPA). First order DPA is now well known and can be prevented by securely proven countermeasures. In 2008, some results are known for second order, but none for third order. The goal of this thesis is to propose a frame for k-th order DPA where k>1. We developed several masking schemes as alternatives to the classical ones in order to propose a better complexity-security ratio. These schemes make use of various mathematical operations such as field multiplication or matrix product and cryptographic tools as secret sharing and multi-party computation. We estimated the security of the proposed schemes following a methodology using both theoretical analysis and practical results. At last we proposed an evaluation of the action of the word size of a cryptographic algorithm upon its resistance against side channel attacks, with respect to the masking scheme implemented