Dissertationen zum Thema „Sécurité de la mémoire“
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Ouattara, Frédéric. „Primitives de sécurité à base de mémoires magnétiques“. Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTS072.
Der volle Inhalt der QuelleMagnetic memories (MRAM) are one of the emerging non-volatile memory technologies that have experienced rapid development over the past decade. One of the advantages of this technology lies in the varied fields of application in which it can be used. In addition to its primary function of storing information, MRAM is nowadays used in applications such as sensors, RF receivers and hardware security. In this thesis, we are interested in the use of MRAMs in the design of elementary hardware security primitives. Initially, an exploration in the design of TRNG (True Random Number Generator) based on STT-MRAM (Spin Transfert Torque MRAM) type memories was carried out with the aim of producing a demonstrator and proving its effectiveness for secure applications. Random extraction methods in STT and TAS (Thermally Assisted Switching) memories are presented. We have thus evaluated these magnetic memories within the framework of TRNGs but also for the generation of PUFs (Physically Unclonable Functions) on physical devices
Millon, Etienne. „Analyse de sécurité de logiciels système par typage statique“. Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://tel.archives-ouvertes.fr/tel-01067475.
Der volle Inhalt der QuelleMillon, Etienne. „Analyse de sécurité de logiciels système par typage statique“. Electronic Thesis or Diss., Paris 6, 2014. http://www.theses.fr/2014PA066120.
Der volle Inhalt der QuelleOperating system kernels need to manipulate data that comes from user programs through system calls. If it is done in an incautious manner, a security vulnerability known as the Confused Deputy Problem can lead to information disclosure or privilege escalation. The goal of this thesis is to use static typing to detect the dangerous uses of pointers that are controlled by userspace. Most operating systems are written in the C language. We start by isolating Safespeak, a safe subset of it. Its operational semantics as well as a type system are described, and the classic properties of type safety are established. Memory states are manipulated using bidirectional lenses, which can encode partial updates to states and variables. A first analysis is described, that identifies integers used as bitmasks, which are a common source of bugs in C programs. Then, we add to Safespeak the notion of pointers coming from userspace. This breaks type safety, but it is possible to get it back by assigning a different type to the pointers that are controlled by userspace. This distinction forces their dereferencing to be done in a controlled fashion. This technique makes it possible to detect two bugs in the Linux kernel: the first one is in a video driver for an AMD video card, and the second one in the ptrace system call for the Blackfin architecture
Eluard, Marc. „Analyse de sécurité pour la certification d'applications java card“. Rennes 1, 2001. http://www.theses.fr/2001REN10079.
Der volle Inhalt der QuelleClavier, Christophe. „De la sécurité physique des crypto-systèmes embarqués“. Versailles-St Quentin en Yvelines, 2007. http://www.theses.fr/2007VERS0028.
Der volle Inhalt der QuelleIn a world full of threats, the development of widespread digital applications has led to the need for a practical device containing cryptographic functions that provide the everyday needs for secure transactions, confidentiality of communications, identification of the subject or authentication for access to a particular service. Among the cryptographic embedded devices ensuring these functionalities, smart cards are certainly the most widely used. Their portability (a wallet may easily contain a dozen) and their ability to protect its data and programs against intruders, make it as the ideal ``bunker'' for key storage and the execution of cryptographic functions during mobile usage requiring a high level of security. Whilst the design of mathematically robust (or even proven secure in some models) cryptographic schemes is an obvious requirement, it is apparently insufficient in the light of the first physical attacks that were published in 1996. Taking advantage of weaknesses related to the basic implementation of security routines, these threats include side-channel analysis which obtains information about the internal state of the process, and the exploitation of induced faults allowing certain cryptanalysis to be performed which otherwise would not have been possible. This thesis presents a series of research works covering the physical security of embedded cryptosystems. Two parts of this document are dedicated to the description of some attacks and to a study of the efficiency of conceivable countermeasures. A third part deals with that particular and still mainly unexplored area which considers the applicability of physical attacks when the cryptographic function is, partly or totally, unknown by the adversary
Lacroix, Patrice. „RTL-Check : a practical static analysis framework to verify memory safety and more“. Thesis, Université Laval, 2006. http://www.theses.ulaval.ca/2006/23909/23909.pdf.
Der volle Inhalt der QuelleSince computers are ubiquitous in our society and we depend more and more on programs to accomplish our everyday activities, bugs can sometimes have serious consequences. A large proportion of existing programs are written in C or C++ and the main source of errors with these programming languages is the absence of memory safety. Our long term goal is to be able to verify if a C or C++ program accesses memory correctly in spite of the deficiencies of these languages. To that end, we have created a static analysis framework which we present in this thesis. It allows building analyses from small reusable components that are automatically bound together by metaprogramming. It also incorporates the visitor design pattern and algorithms that are useful for the development of static analyses. Moreover, it provides an object model for RTL, the low-level intermediate representation for all languages supported by GCC. This implies that it is possible to design analyses that are independent of programming languages. We also describe the modules that comprise the static analysis we have developed using our framework and which aims to verify if a program is memory-safe. This analysis is not yet complete, but it is designed to be easily improved. Both our framework and our memory access analysis modules are distributed in RTL-Check, an open-source project.
Saleh, Hayder. „Une architecture novatrice de sécurité à base de carte à puce Internet“. Versailles-St Quentin en Yvelines, 2002. http://www.theses.fr/2002VERSA009.
Der volle Inhalt der QuelleDavidson, Tremblay Patrick. „Protection et intégrité des systèmes embarqués réseautés“. Mémoire, Université de Sherbrooke, 2014. http://hdl.handle.net/11143/5896.
Der volle Inhalt der QuelleElbaz, Reouven. „Mécanismes Matériels pour des TransfertsProcesseur Mémoire Sécurisés dans lesSystèmes Embarqués“. Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2006. http://tel.archives-ouvertes.fr/tel-00142209.
Der volle Inhalt der Quellecomme des hôtes de confiance car toute personne y ayant accès, sont des attaquants potentiels. Les données
contenues dans ces systèmes peuvent être sensibles (données privées du propriétaire, mot de passe, code d'un
logiciel...) et sont généralement échangées en clair entre le Système sur Puces (SoC – System on Chip) et la
mémoire dans laquelle elles sont stockées. Le bus qui relie ces deux entités constitue donc un point faible : un
attaquant peut observer ce bus et récupérer le contenu de la mémoire, ou bien a la possibilité d'insérer du code
afin d'altérer le fonctionnement d'une application s'exécutant sur le système. Afin de prévenir ce type d'attaque,
des mécanismes matériels doivent être mis en place afin d'assurer la confidentialité et l'intégrité des données.
L'approche conventionnelle pour atteindre cet objectif est de concevoir un mécanisme matériel pour chaque
service de sécurité (confidentialité et intégrité). Cette approche peut être implantée de manière sécurisée mais
empêche toute parallélisation des calculs sous-jacents.
Les travaux menés au cours de cette thèse ont dans un premier temps, consisté à faire une étude des
techniques existantes permettant d'assurer la confidentialité et l'intégrité des données. Dans un deuxième temps,
nous avons proposé deux mécanismes matériels destinés à la sécurisation des transactions entre un processeur et
sa mémoire. Un moteur de chiffrement et de contrôle d'intégrité parallélisé, PE-ICE (Parallelized Encryption and
Integrity Checking Engine) a été conçu. PE-ICE permet une parallélisation totale des opérations relatives à la
sécurité aussi bien en écriture qu'en lecture de données en mémoire. Par ailleurs, une technique basée sur une
structure d'arbre (PRV-Tree – PE-ICE protected Reference Values) comportant la même propriété de
parallélisation totale, a été spécifiée afin de réduire le surcoût en mémoire interne impliqué par les mécanismes de sécurité
Kamel, Nassima. „Sécurité des cartes à puce à serveur Web embarqué“. Limoges, 2012. https://aurore.unilim.fr/theses/nxfile/default/9dc553cd-e9df-4530-a716-d3191d68dfa0/blobholder:0/2012LIMO4039.pdf.
Der volle Inhalt der QuelleSmart cards are widely used secure devices in today’s world, which can store data in a secured manner and ensure data security during transactions. The success of smart card is mainly due to their tamper-resistant nature which allows them to store sensitive data’s like cryptographic keys. Since they are using in multiple secure domains, like banking, health insurance, etc. More and more researches are taken place in this domain for security and attacks. The last generation of smart card, defines an embedded web server. There are two types of specifications for these devices, the first one is defined by OMA organisation that propose a simple HTTP web server named Smart Card Web Server (SCWS), the second is proposed by Sun Microsystems (currently Oracle), consists of a Java card 3 connected edition platform, that includes a Java servlet 2. 4 API with improved Java Card API and security features. In addition to network benefits from the robustness of smart card, the use of web standards provide a continuous user experience, equivalent to that seen while surfing on the internet and it enhances the look and feel of GUI interfaces. The GUI interfaces are accessible from a browser which is located on the terminal on which the card is connected. However, in addition to the classical attacks (physical and logical), the integration of web server on smart card, exposes the smart card to some existing classical web application attacks. The most important one is the cross site scripting attack, also named XSS. It consists of injecting malicious data to the given web application inputs and if the resource returned to the browser includes the malicious code, it will be interpreted and executed, causing an attack. A web application is vulnerable to XSS if it uses an untrusted data without filtering malicious characters before. On the other hand, to ensure the communication between web applications and browser or other network entities, it is necessary to integrate some protocols to the smart card, for example HTTP, BIP or TCP/IP. The vulnerabilities in the implementation of these protocols can facilitate some attacks. Our contribution on this thesis is divided in two parts, in the first part, we are interested on the security of web applications against XSS attack. We suggest a static analysis tool, based on tainting approach, that allow to verify if a web application is secured or not, including filtering data in all insertion points where XSS is possible. We also implement, an API filter, compatible with Java Card 3 platform, that developers can import during the development of their applications. The second part consists of verifying the conformance and the robustness of the implemented HTTP protocol. For that we propose an intelligent fuzzing tool that includes a set of optimisations that allows to reduce the time of fuzzing
Sifakis, Emmanuel. „Programmation efficace et sécurisé d'applications à mémoire partagée“. Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00823054.
Der volle Inhalt der QuelleBuret, Pierrick. „Sécurité temps réel dans les systèmes embarqués critiques“. Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0140/document.
Der volle Inhalt der QuelleSatellites are real-time embedded systems and will be used more and more in the world. Become essential for the geo-location, meteorology or communications across the planet, these systems are increasingly in demand. Due to the influx of requests, the designers of these products are designing a more and more complex hardware and software part. Thanks to the evolution of terrestrial equipment, the aero-space field is turning to new technologies such as caches, multi-core, and hypervisor. The integration of these new technologies bring new technical challenges. In effect, it is necessary to improve the performance of these systems by reducing the cost of manufacturing and the production time. One of the major advantages of these technologies is the possibility of reducing the overall number of satellites in space while increasing the number of operators. Multiple clients softwares may be together today in a same satellite. The ability to integrate multiple customers on the same satellite, with the increasing complexity of the system, makes a number of malicious acts possible. These acts were once considered as hypothetical. Become a priority today, the study of the vulnerability of such systems become major. In this paper, we present first work a quick exploration of the field of malicious acts on onboard system and more specifically those carried out on satellite system. Once the risk presentation we will develop some particular points, such as the problematic real-time. In this thesis we are particularly interested in the security of space hypervisors. We will develop precisely 2 lines of research. The first axis is focused on the development of production technics and implementing a control system of a satellite temporal characteristics. The objective is to adapt an existing system to the constraints of the new highly complex systems. We confront the difficulty of measuring the temporal characteristics running on a satellite system. For this we use an optimization method called dynamic analysis and genetic algorithm. Based on trends, it can automatically search for the worst execution time of a given function. The second axis improves the technical knowledge on a satellite in operation and enables decision making in case of malicious act. We propose specifically a physical solution to detect anomalies in the management of internal memory to the satellite. Indeed, memory is an essential component of system operation, and these common properties between all clients makes them particularly vulnerable to malicious acts. Also, know the number of memory access enables better scheduling and better predictability of a real time system. Our component allows the detection and interpretation of a potential attack or dependability problem. The work put in evidence the complementarity of the two proposed work. Indeed, the measure of the number of memory access that can be measured via a genetic algorithm whose shape is similar to the program seeking the worst execution time. So we can expand our work of the first part with the second
Kamel, Sarah. „Sécurité pour les réseaux sans fil“. Thesis, Paris, ENST, 2017. http://www.theses.fr/2017ENST0011/document.
Der volle Inhalt der QuelleToday, there is a real need to strengthen the communication security to anticipate the development of quantum computing and the eventual attacks arising from it. This work explores two complementary techniques that provide confidentiality to data transmitted over wireless networks. In the first part, we focus on lattice-based public-key cryptography, which is one of the most promising techniques for the post-quantum cryptography systems. In particular, we focus on the Goldreich-Goldwasser-Halevi (GGH) cryptosystem, for which we propose a new scheme using GLD lattices. In the second part of this work, we study the security of multi-user cache-aided wiretap broadcast channels (BCs) against an external eavesdropper under two secrecy constraints: individual secrecy constraint and joint secrecy constraint. We compute upper and lower bounds on secure capacity-memory tradeoff considering different cache distributions. To obtain the lower bound, we propose different coding schemes that combine wiretap coding, superposition coding and piggyback coding. We prove that allocation of the cache memory to the weaker receivers is the most beneficial cache distribution scenario
Barbu, Guillaume. „De la sécurité des platesformes JavaCardTM face aux attaques matérielles“. Electronic Thesis or Diss., Paris, ENST, 2012. http://www.theses.fr/2012ENST0037.
Der volle Inhalt der QuelleSmart cards play a key role in various applications we use on a daily basis: payment, mobile communication, public transports, etc. In this context, the Java Card technology has evolved since its introduction in the mid-nineties to become nowadays the world leading smart card platform. In the context of Java Card, researches on security have revealed that the possibility of loading malicious applications represents a real threat. In the meantime, the scientific community has also paid interest to the security of embedded cryptography, revealing that theoretically strong cryptosystems can be easily broken if their implementation does not take into account certain physical properties of the underlying hardware device. In particular, a part of the published attacks relies on the attacker’s capacity to physically perturb the component during a cryptographic operation. These latter fault attacks have been rarely considered in the literature in the Java Card context. In this thesis, we study and evaluate the security of Java Cards against the combination of fault and software attacks in order to enhance it. First, we present various attack paths involving both hardware and software attacks and expose how these attacks allow to break various security mechanisms of Java Cards. In particular, our security analysis proves that the type-safety property, the control-flow integrity and the application isolation can be tampered with by the combination of adequate fault injections and malicious applications. Then, with regards to the goal of this thesis and the results of our security analysis, we present different approaches allowing to improve the resistance of Java Cards and Java Card applications against combined attacks. Thus we define several countermeasures against the attack we exposed as well as against some of the state-of-the-art attacks, always bearing in mind the strong constraints relative to smart cards
Séré, Ahmadou Al Khary. „Tissage de contremesures pour machines virtuelles embarquées“. Limoges, 2010. http://aurore.unilim.fr/theses/nxfile/default/ec9d960e-5234-4fd7-a38f-bd8107443f05/blobholder:0/2010LIMO4017.pdf.
Der volle Inhalt der QuelleOur goal, is to propose some way to guaranty that we can detect that a fault attack occurs tampering the smart card ship. And we want to do this in an automatic way that is affordable in resources (memory and CPU averhead) for the card. To achieve this goal, we use a functionality introduced by Java Card 3, the security annotations that allow a programmer to choose sensitive methods or classes of his application. Allowing the virtual machine to execute them in a secured mode. The developed approach is to use security information introduce in application code and to modify the java virtual machine to make good use of them to detect the attack. These researches focus on proposing different mechanisms that can help to fight against fault attacks in verifying during runtime the code integrity or the control flow integrity
Barbu, Guillaume. „De la sécurité des platesformes JavaCardTM face aux attaques matérielles“. Phd thesis, Télécom ParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00834324.
Der volle Inhalt der QuelleDang, Alexandre. „Compilation sécurisée pour la protection de la mémoire“. Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S111.
Der volle Inhalt der QuelleOur society has been growingly dependent on computer systems and this tendency will not slow down in the incoming years. Similarly, interests over cybersecurity have been increasing alongside the possible consequences brought by successful attacks on these systems. This thesis tackles the issue of security of systems and especially focuses on compilation to achieve its goal. Compilation is the process of translating source programs written by humans to machine code readable by our systems. We explore the two possible behaviours of a secure compiler which are enforcement and preservation. First, we have developed CompCertSFI, a compiler which enforces the isolation of modules into closed memory areas called sandboxes. These modules are then unable to access memory regions outside of their sandbox which prevents any malicious module from corrupting other entities of the system. On the topic of security preservation, we defined a notion of Information Flow Preserving transformation to make sure that a program does get less secure during compilation. Our property is designed to preserve security against side-channel attacks. This new category of attacks uses physical mediums such as time or power consumption which are taken into account by current compilers
Kamel, Sarah. „Sécurité pour les réseaux sans fil“. Electronic Thesis or Diss., Paris, ENST, 2017. http://www.theses.fr/2017ENST0011.
Der volle Inhalt der QuelleToday, there is a real need to strengthen the communication security to anticipate the development of quantum computing and the eventual attacks arising from it. This work explores two complementary techniques that provide confidentiality to data transmitted over wireless networks. In the first part, we focus on lattice-based public-key cryptography, which is one of the most promising techniques for the post-quantum cryptography systems. In particular, we focus on the Goldreich-Goldwasser-Halevi (GGH) cryptosystem, for which we propose a new scheme using GLD lattices. In the second part of this work, we study the security of multi-user cache-aided wiretap broadcast channels (BCs) against an external eavesdropper under two secrecy constraints: individual secrecy constraint and joint secrecy constraint. We compute upper and lower bounds on secure capacity-memory tradeoff considering different cache distributions. To obtain the lower bound, we propose different coding schemes that combine wiretap coding, superposition coding and piggyback coding. We prove that allocation of the cache memory to the weaker receivers is the most beneficial cache distribution scenario
Sauveron, Damien. „Etude et réalisation d'un environnement d'expérimentation et de modélisation pour la technologie Java Card : application à la sécurité“. Bordeaux 1, 2004. http://www.theses.fr/2004BOR12930.
Der volle Inhalt der QuelleMaréchal, Catherine. „Etude de l'influence de la technologie et de l'association de composants logiques sur la sensibilité électromagnétique de cartes électroniques : Application à l'étude d'une fonction dont la sécurité est fondée sur la redondance matérielle“. Lille 1, 1994. http://www.theses.fr/1994LIL10109.
Der volle Inhalt der QuelleHély, David. „Conception en vue du test de circuits sécurisés“. Montpellier 2, 2005. http://www.theses.fr/2005MON20123.
Der volle Inhalt der QuelleBolignano, Pauline. „Formal models and verification of memory management in a hypervisor“. Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S026/document.
Der volle Inhalt der QuelleA hypervisor is a software which virtualizes hardware resources, allowing several guest operating systems to run simultaneously on the same machine. Since the hypervisor manages the access to resources, a bug can be critical for the guest Oses. In this thesis, we focus on memory isolation properties of a type 1 hypervisor, which virtualizes memory using Shadow Page Tables. More precisely, we present a low-level and a high-level model of the hypervisor, and we formally prove that guest OSes cannot access or tamper with private data of other guests, unless they have the authorization to do so. We use the language and the proof assistant developed by Prove & Run. There are many optimizations in the low-level model, which makes the data structures and algorithms complexes. It is therefore difficult to reason on such a model. To circumvent this issue, we design an abstract model in which it is easier to reason. We prove properties on the abstract model, and we prove its correspondence with the low-level model, in such a way that properties proved on the abstract model also hold for the low-level model. The correspondence proof is valid only for low-level states which respect some properties. We prove that these properties are invariants of the low-level system. The proof can be divided into three parts : the proof of invariants preservation on the low-level, the proof of correspondence between abstract and low-level models, and proof of the security properties on the abstract level
Elbaz, Reouven. „Mécanismes matériels pour des transferts processeur mémoire sécurisés dans les systèmes embarqués“. Montpellier 2, 2006. http://www.theses.fr/2006MON20119.
Der volle Inhalt der QuelleBresch, Cyril. „Approches, Stratégies, et Implémentations de Protections Mémoire dans les Systèmes Embarqués Critiques et Contraints“. Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALT043.
Der volle Inhalt der QuelleThis thesis deals with the memory safety issue in life-critical medical devices. Over the last few years, several vulnerabilities such as memory exploits have been identified in various Internet of Medical Things (IoMT) devices. In the worst case, such vulnerabilities allow an attacker to remotely force an application to execute malicious actions. While many countermeasures against software exploits have beenproposed so far, only a few of them seem to be suitable for medical devices. Indeed,these devices are constrained by their size, real-time performances, and safety requirements making the integration of security challenging. To address this issue,the thesis proposes two approaches. Both address the memory safety issue fromthe software design-time to its run-time on the hardware. A first approach assumesthat memory defenses can be implemented both in hardware and software. Thisapproach results in TrustFlow, a framework composed of a compiler able to generatesecure code for an extended processor that can prevent, detect, log, andself-heal critical applications from memory attacks. The second approach considersthat hardware is immutable. Following this constraint, defenses only rely uponsoftware. This second approach results in BackGuard a modified compiler that efficiently hardens embedded applications while ensuring control-flow integrity
Jensen, Christian Damsgaard. „Un modèle de contrôle d'accès générique et sa réalisation dans la mémoire virtuelle répartie unique Arias“. Phd thesis, Université Joseph Fourier (Grenoble), 1999. http://tel.archives-ouvertes.fr/tel-00004841.
Der volle Inhalt der QuelleBeringuier-Boher, Noémie. „Evaluation et amélioration de la sécurité des circuits intégrés analogiques“. Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT007.
Der volle Inhalt der QuelleWith the development of the Internet of things, the number of connected devices is in constant increase. These objects use a large amount of data including personal credentials. Therefore, security has become a major constraint for System on Chips (SoCs) designers. Moreover, in a context more and more aggressive in terms of performances and time to market, it is important to find low cost security solutions. Although the hardware security is often treated from a digital point of view, almost every SoCs is also using analog and mixed IP. Thus, this work presents different steps to improve the security of analog IPs, from vulnerability analysis to countermeasures design validation, and behavioral modeling in the context of mixed signals and low cost applications. To protect any system, the first requirement is to know its vulnerabilities. To do so, a vulnerability analysis methodology dedicated to analog circuit has been developed. Using the results of this analysis, countermeasures can be designed during the development of the circuit and not at the end. The circuit security is thus improved without dramatically increasing its cost in terms of design time. The analysis of a clock system generator, an analog IP widely used in current SoCs and composed with various sub-circuits, has shown fault attacks using Laser Photoelectric Stimulation (LPS) or supply voltage glitches as important threats. After having identified the 2 previous attacks types as major threats, their effects on analog circuits are analyzed. Existing countermeasures are then compared and evaluated for the protection of analog IPs. To complete these solutions, two analog detectors have been designed to detect laser and supply voltage glitch attacks considering SoCs level constraints. Electrical test of these detectors processed on CMOS 28nm FD-SOI technology proved their efficiency. Theoretical vulnerability analysis has shown some difficulties. Indeed, analog circuits are sensitive to numerous parametrical faults. Also, the high interconnection of various sub-circuits makes the faults propagation analysis quite difficult. To help this analysis, electrical simulations at transistor level are necessary. These simulations are quite long and, so the behavioral modeling of analog circuits to help the analysis of supply voltage glitch attack effects has been studied. To do so, the developed models must be developed according different constraints presented in this report and applied to the behavioral modeling of a real analog circuit. This illustration proved that behavioral models can be used to help to identify which attack shapes are the most likely to induce faults in the circuit
Pagani, Fabio. „Advances in memory forensics“. Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS299.
Der volle Inhalt der QuelleThe adoption of memory forensics - the art of extracting artifacts from the volatile memory of a compromised system - is spreading in cyber-security investigations. The main reason of this enthusiasm comes from the fact that many artifacts can not be found elsewhere. In this way, the forensics analysts can gain the big picture over a malicious behavior. Nevertheless, memory forensics is less than two decades old: many challenges are unsolved and many questions are unanswered. This thesis gives a new perspective over three of these problems. The first contribution studies the effects non-atomic acquisition methods. The root cause of this problem is quite straightforward to explain: while the memory is acquired, user and kernel processes are running and therefore modifying the content of the memory. For this reason, the resulting memory dump does not represent the state of the memory in a given point in time, but rather a mix of multiple points. The second contribution focus on automatically extracting a forensics profile from a memory dump. Having a valid profile is a strong requirement for memory analysis because without one any structured memory forensics technique can be applied. Therefore, this problem effectively prevents memory forensics to be applied in those scenarios where creating a profile is harder -- if not impossible. The third and last contribution of this thesis aims to change how forensics rules, better known as plugins, are created. Nowadays, these rules are manually written by kernel experts and forensics practitioners. Unfortunately, this manual approach does not have any guarantee on the quality or on the uniqueness of these rules
Coisel, Iwen. „Authentification et Anonymat à Bas-coût : Modélisations et Protocoles“. Caen, 2009. http://www.theses.fr/2009CAEN2041.
Der volle Inhalt der QuelleIn our daily life, security of many applications are based on cryptographic mechanisms. In some of them, privacy issues are a major concern. For example in internet context, a user expects the service provider not to divulgate his identity. In this thesis, I first give a formal definition of zero-knowledge proofs of knowledge (ZKPK), very useful for designing digital signatures. I prove the security of a generic construction of proofs of knowledge of discrete logarithm relations set. Then, I present state of the art of different signature schemes ensuring users' anonymity. Afterwards I adapt these protocols to the cooperative set-up, in which an intermediary helps the user perform some computations during the protocol. I also define a formal security model which is robust against corruption of the intermediary, while improving protocol efficiency. In the second part of this thesis, I present the security requirements for RFID tags authentication protocols. As these small embedded devices are potentially integrated into many various products, they must be intraceable so that nobody can trace their holder. As anonymity does not provide this property on its own, it must be included in the security model. Finally, I describe two authentication protocols which provide this security level. The first one uses a secret key infrastructure and a key update mechanism. The other one uses a public key infrastructure and an encryption algorithm
Vaquié, Bruno. „Contributions à la sécurité des circuits intégrés face aux attaques par canaux auxiliaires“. Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20133/document.
Der volle Inhalt der QuelleSide channel attacks such as power analysis attacks are a threat to the security of integrated circuits.They exploit the physical leakage of circuits during the cryptographic computations to retrieve the secret informations they contain. Many countermeasures, including hardware, have been proposed by the community in order to protect cryptosystems against such attacks. Despite their effectiveness, their major drawback is their significant additional cost in area, speed and consumption. This thesis aims at proposing low cost countermeasures able to reduce the leaks and offering a good compromise between security and costs. First we identify the main sources of leakage of a cryptographic system that integrates an iterative hardware architecture of a symetric algorithm. Then we propose several low cost countermeasures, which aim at reducing this leakage. Finally, we evaluate the robustness of our solutions against side channel attacks
Vandewalle, Jean-Jacques. „Projet OSMOSE : modélisation et implémentation pour l'interopérabilité de services carte à microprocesseur par l'approche orientée objet“. Lille 1, 1997. http://www.theses.fr/1997LIL10233.
Der volle Inhalt der QuelleOuaarab, Salaheddine. „Protection du contenu des mémoires externes dans les systèmes embarqués, aspect matériel“. Thesis, Paris, ENST, 2016. http://www.theses.fr/2016ENST0046/document.
Der volle Inhalt der QuelleDuring the past few years, computer systems (Cloud Computing, embedded systems...) have become ubiquitous. Most of these systems use unreliable or untrusted storage (flash, RAM...)to store code or data. The confidentiality and integrity of these data can be threaten by hardware (spying on the communication bus between the processing component and the storage component) or software attacks. These attacks can disclose sensitive information to the adversary or disturb the behavior of the system. In this thesis, in the context of embedded systems, we focused on the attacks that threaten the confidentiality and integrity of data that are transmittedover the memory bus or that are stored inside the memory. Several primitives used to protect the confidentiality and integrity of data have been proposed in the literature, including Merkle trees, a data structure that can protect the integrity of data including against replay attacks. However, these trees have a large impact on the performances and the memory footprint of the system. In this thesis, we propose a solution based on variants of Merkle trees (hollow trees) and a modified cache management mechanism to greatly reduce the impact of the verification of the integrity. The performances of this solution have been evaluated both theoretically and in practice using simulations. In addition, a proof a security equivalence with regular Merkle treesis given. Finally, this solution has been implemented in the SecBus architecture which aims at protecting the integrity and confidentiality of the content of external memories in an embedded system. A prototype of this architecture has been developed and the results of its evaluation are given
Atallah, Eve. „Une solution pour l'établissement non planifié de groupes sécurisés permettant des communications sûres dans les réseaux MANets purs“. Limoges, 2008. https://aurore.unilim.fr/theses/nxfile/default/dc02beb3-c3d0-4717-8d6f-6a3706b2da76/blobholder:0/2008LIMO4060.pdf.
Der volle Inhalt der QuelleThe work presented in this thesis is about MANets with no centralization or administration and where users are highly mobile and not necessarily linked together within a human organization. Our contribution is a decentralized architecture that makes it possible to secure communication within such networks. Its implementation, the SManet application, is based on an administrator module embedded in a mart card which is in charge of the tasks usually carried out by a centralized entity. Each mobile treminal is equipped with a card embedding such a module that controls the operations ensuring the correct behavior of its host and the security of the communications with the other card holders. This solution supports the establishment of secure exchanges, anywhere, anytime, with no planning and thus without any prior underlying human organization
Karray, Achraf. „Conception, mise en œuvre et validation d’un environnement logiciel pour le calcul sécurisé sur une grille de cartes à puce de type Java“. Thesis, Bordeaux 1, 2008. http://www.theses.fr/2008BOR13724/document.
Der volle Inhalt der QuelleAbstract
Kussener-Combier, Edith. „Conception de circuits intégrés de régulation intelligente pour les microprocesseurs sécurisés (carte à puce)“. Lille 1, 2002. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2002/50376-2002-117.pdf.
Der volle Inhalt der QuelleCe circuit additionnel permet en particulier de réaliser une conversion et une régulation de tension de gain unitaire. La phase de conception de ces convertisseurs nécessite une interprétation correcte des résultats de simulation. Dans ce sens, vue de l'alimentation, une macro modélisation de l'activité du microprocesseur est nécessaire. Une macro modélisation basée sur la simulation et la programmation de plusieurs inverseurs logiques est proposée. Les mesures effectuées sur plusieurs prototypes confirment bien l'interprétation théorique proposée ainsi que les résultats attendus à partir des simulations. Différentes solutions permettent de crypter les informations confidentielles qui circulent aux travers des plots d'alimentations des cartes à puces. Les solutions proposées consistent à ajouter des blocs sécuritaires élémentaires pouvant être pilotés par le microprocesseur via des algorithmes de cryptage
Bozzio, Mathieu. „Security and implementation of advanced quantum cryptography : quantum money and quantum weak coin flipping“. Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLT045.
Der volle Inhalt der QuelleHarnessing the laws of quantum theory can drastically boost the security of modern communication networks, from public key encryption to electronic voting and online banking. In this thesis, we bridge the gap between theory and experiment regarding two quantum-cryptographic tasks: quantum money and quantum weak coin flipping. Quantum money exploits the no-cloning property of quantum physics to generate unforgeable tokens, banknotes, and credit cards. We provide the first proof-of-principle implementation of this task, using photonic systems at telecom wavelengths. We then develop a practical security proof for quantum credit card schemes, in which the bank can remotely verify a card even in the presence of a malicious payment terminal. We finally propose a setup for secure quantum storage of the credit card, using electromagnetically-induced transparency in a cloud of cold cesium atoms. Quantum weak coin flipping is a fundamental cryptographic primitive, which helps construct more complex tasks such as bit commitment and multiparty computation. It allows two distant parties to flip a coin when they both desire opposite outcomes. Using quantum entanglement then prevents any party from biasing the outcome of the flip beyond a certain probability. We propose the first implementation for quantum weak coin flipping, which requires a single photon and linear optics only. We provide the complete security analysis in the presence of noise and losses, and show that the protocol is implementable on the scale of a small city with current technology. We finally propose a linear-optical extension of the protocol to lower the coin bias
Ouaarab, Salaheddine. „Protection du contenu des mémoires externes dans les systèmes embarqués, aspect matériel“. Electronic Thesis or Diss., Paris, ENST, 2016. http://www.theses.fr/2016ENST0046.
Der volle Inhalt der QuelleDuring the past few years, computer systems (Cloud Computing, embedded systems...) have become ubiquitous. Most of these systems use unreliable or untrusted storage (flash, RAM...)to store code or data. The confidentiality and integrity of these data can be threaten by hardware (spying on the communication bus between the processing component and the storage component) or software attacks. These attacks can disclose sensitive information to the adversary or disturb the behavior of the system. In this thesis, in the context of embedded systems, we focused on the attacks that threaten the confidentiality and integrity of data that are transmittedover the memory bus or that are stored inside the memory. Several primitives used to protect the confidentiality and integrity of data have been proposed in the literature, including Merkle trees, a data structure that can protect the integrity of data including against replay attacks. However, these trees have a large impact on the performances and the memory footprint of the system. In this thesis, we propose a solution based on variants of Merkle trees (hollow trees) and a modified cache management mechanism to greatly reduce the impact of the verification of the integrity. The performances of this solution have been evaluated both theoretically and in practice using simulations. In addition, a proof a security equivalence with regular Merkle treesis given. Finally, this solution has been implemented in the SecBus architecture which aims at protecting the integrity and confidentiality of the content of external memories in an embedded system. A prototype of this architecture has been developed and the results of its evaluation are given
Lacharme, Patrick. „Générateur vraiment aléatoire dans un composant sécurisé“. Toulon, 2007. http://www.theses.fr/2007TOUL0025.
Der volle Inhalt der QuelleSystems of security based on cryptographic algorithm; use a lot of random HP-quences. For smart card applications, a random generator must to have a small size, without fails in its security. The main objective of this thesis is to propose an alternative to classical generators, in order to be inplemented on small components. The differonts parts of this work are the construction of an architecture for a random generator for small size components, the analysis and the inplementation of the mathematical corrector for an estimation of the quality of the. Output random sequence
Oliveri, Andrea. „A Zero-Knowledge Approach to Memory Forensics“. Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS312.
Der volle Inhalt der QuelleThe rapid increase of embedded devices and IoT objects is leading to a multiplication of operating systems and processor architectures, which are generally not supported by current forensic tools and require considerable effort to adapt. To overcome this problem, we introduce the concept of zero-knowledge memory forensics: performing a memory forensic analysis without any knowledge of the underlying operating system. Assuming that we have performed a memory dump of the unknown operating system, using only information derived from the machine's hardware configuration, we claim that it is possible to reconstruct the kernel address space independently of the operating system. From these, it is possible to reconstruct kernel data structures in memory using only their topology
Harrari, Mounia. „Hybridation CMOS/STT-MRAM des circuits intégrés pour la sécurité matérielle de l'Internet des Objets“. Electronic Thesis or Diss., Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0621.
Der volle Inhalt der QuelleIn the last decade, the Internet of Things deployment highlighted new needs and constraints in terms of consumption and area for integrated circuits. However, the recent craze for connected objects and due to the extremely pressing time-to-market demand, the manufacturers commercialize their products, sometimes at the expense of their security. The main focus of the work undertook during this thesis consists in the hybridization of the CMOS technology with the emerging non-volatile memory technology STT-MRAM. This study aims to determine the assets and drawbacks of this hybridization. These innovating architectures must allow the development of low power applications and support the growth of secured connected objects. Thus, the design of a hybrid CMOS/STT-MRAM lightweight cryptographic algorithm based on the PRESENT cipher is realised.This is how the first study carried out consisted in investigating the robustness of STT-MRAM junctions facing physical attacks, before their integration in the cryptographic algorithm. To do this, laser fault injections were performed in order to evaluate the integrity of the sensitive data stored in the cells.Following the observations carried out on these experiments on perpendicular STT-MRAM memories, a new physical attack detector based on this memory technology is proposed, designated by DDHP. This sensor allows simultaneous detection of photoelectrical and thermal attacks that can target integrated circuits
Rammal, Darine. „Memory safety for synchronous reactive programming“. Electronic Thesis or Diss., Orléans, 2024. http://www.theses.fr/2024ORLE1002.
Der volle Inhalt der QuelleSynchronous Reactive Languages are an excellent choice for IoT programming due to their clear system-environment interaction semantics. However, when it comes to safety- critial or resource-constrained systems, recent proposals like Fairthreads or ReactiveML face a well-known issue. Fairthreads' manual memory management can lead to errors, while ReactiveML's garbage collection ensures memory safety but introduces execution overhead. This thesis aims to address the memory safety issue by developing a reactive programming language specifically designed for real-time systems, incorporating cooperative threads and synchronous execution. Drawing from the robust type system of the Rust programming language, we propose a Rust-like type system for a kernel reactive programming language named MSSL. MSSL features a cooperative threading model and facilitates mutable data sharing between threads while preserving type and borrowing safety. To achieve this, we introduce a novel abstraction called Trc (Thread Reference Counting), which combines the ownership safety of Rust references with the reference counting mechanism of Rust smart pointers. Then, we present the semantics and type system of MSSL to demonstrate its capabilities in maintaining type safety, borrowing safety, and concurrency safety. Furthermore, we extend MSSL by introducing reactive extensions, incorporating the concept of signals that offer powerful, flexible, and reliable means of communication. Finally, we provide a Java implementation of the complete MSSL set, based on the semantic and typing rules of its type system
Benzine, Mehdi. „Combinaison sécurisée des données publiques et sensibles dans les bases de données“. Versailles-St Quentin en Yvelines, 2010. http://www.theses.fr/2010VERS0024.
Der volle Inhalt der QuelleProtection of sensitive data is a major issue in the databases field. Many software and hardware solutions have been designed to protect data when stored and during query processing. Moreover, it is also necessary to provide a secure manner to combine sensitive data with public data. To achieve this goal, we designed a new storage and processing architecture. Our solution combines a main server that stores public data and a secure server dedicated to the storage and processing of sensitive data. The secure server is a hardware token which is basically a combination of (i) a secured microcontroller and (ii) a large external NAND Flash memory. The queries which combine public and sensitive data are split in two sub queries, the first one deals with the public data, the second one deals with the sensitive data. Each sub query is processed on the server storing the corresponding data. Finally, the data obtained by the computation of the sub query on public data is sent to the secure server to be mixed with the result of the computation on sensitive data. For security reasons, the final result is built on the secure server. This architecture resolves the security problems, because all the computations dealing with sensitive data are done by the secure server, but brings performance problems (few RAM, asymmetric cost of read/write operations. . . ). These problems will be solved by different strategies of query optimization
Tardif, Florent. „Practical considerations on cryptanalytic time-memory trade-offs“. Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S118.
Der volle Inhalt der QuelleA cryptanalytic time-memory trade-off (TMTO) is a technique that aims to reduce the time needed to perform a set of cryptanalysis attacks, such as inverting a one-way function. Such an inversion constitutes one of the main applications of TMTOs, which is password cracking. The technique relies on a large-scale pre-computation which outputs tables that allow to significantly speed up the attack's exhaustive search. The more memory is used by a TMTO, the faster the attack can be. In practice, the amount of memory available is often the limiting factor, so numerous approaches have been proposed to fit large tables in a restricted amount of memory. In this thesis, we focus on the rainbow tables variant, the most widely spread version of time-memory trade-offs. When the considered cryptographic problem is overwhelmingly sized, using an external memory is eventually needed. We analyse the relevance of using an external memory instead of RAM, and we state that it is fully suited for practical cases, which are identified. We then introduce a new technique, based on minimal perfect hash functions, whose storage complexity is better than any previous optimisation. Finally, we analyse and compare existing TMTO approaches as well as their combinations, along with our newly introduced MPHF rainbow technique. We are then able to provide a set of practical recommendations on how to configure the implementation of a TMTO in an optimal way
Ton, That Dai Hai. „Gestion efficace et partage sécurisé des traces de mobilité“. Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV003/document.
Der volle Inhalt der QuelleNowadays, the advances in the development of mobile devices, as well as embedded sensors have permitted an unprecedented number of services to the user. At the same time, most mobile devices generate, store and communicate a large amount of personal information continuously. While managing personal information on the mobile devices is still a big challenge, sharing and accessing these information in a safe and secure way is always an open and hot topic. Personal mobile devices may have various form factors such as mobile phones, smart devices, stick computers, secure tokens or etc. It could be used to record, sense, store data of user's context or environment surrounding him. The most common contextual information is user's location. Personal data generated and stored on these devices is valuable for many applications or services to user, but it is sensitive and needs to be protected in order to ensure the individual privacy. In particular, most mobile applications have access to accurate and real-time location information, raising serious privacy concerns for their users.In this dissertation, we dedicate the two parts to manage the location traces, i.e. the spatio-temporal data on mobile devices. In particular, we offer an extension of spatio-temporal data types and operators for embedded environments. These data types reconcile the features of spatio-temporal data with the embedded requirements by offering an optimal data presentation called Spatio-temporal object (STOB) dedicated for embedded devices. More importantly, in order to optimize the query processing, we also propose an efficient indexing technique for spatio-temporal data called TRIFL designed for flash storage. TRIFL stands for TRajectory Index for Flash memory. It exploits unique properties of trajectory insertion, and optimizes the data structure for the behavior of flash and the buffer cache. These ideas allow TRIFL to archive much better performance in both Flash and magnetic storage compared to its competitors.Additionally, we also investigate the protect user's sensitive information in the remaining part of this thesis by offering a privacy-aware protocol for participatory sensing applications called PAMPAS. PAMPAS relies on secure hardware solutions and proposes a user-centric privacy-aware protocol that fully protects personal data while taking advantage of distributed computing. For this to be done, we also propose a partitioning algorithm an aggregate algorithm in PAMPAS. This combination drastically reduces the overall costs making it possible to run the protocol in near real-time at a large scale of participants, without any personal information leakage
Kauffmann-Tourkestansky, Xavier. „Analyses sécuritaires de code de carte à puce sous attaques physiques simulées“. Phd thesis, Université d'Orléans, 2012. http://tel.archives-ouvertes.fr/tel-00771273.
Der volle Inhalt der QuelleDuclos, Mathilde. „Méthodes pour la vérification des protocoles cryptographiques dans le modèle calculatoire“. Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAM002/document.
Der volle Inhalt der QuelleCritical and private information are exchanged on public environment. To protect it from dishonest users, we use cryptographic tools. Unfortunately, bad conception, poorly written security properties and required security hypothesis lead to attacks, and it may take years before one discover the attack and fix the security schemes involved. In this context, provable security provides formal definitions for security objectives and implied mathematical proofs that these objectives are fullfilled. On another hand, complexity and variety of cryptographic systems are increasing, and proofs by hand are too complicated to write and to verify (Bellare& Rogaway 2004, Shoup 2004, Halevi 2005). Thus, we need computer-assisted verification methods for cryptographic systems. The aim of this thesis is to progress in this direction. More precisely we want significant progress over formal proofs on cryptographic protocols. To verify cryptographic protocols we need to develop a theoritical framework providing: - a precise modelisation for cryptographic protocols and security properties we want to prove in the computationnal model, - designing tactics to automate proofs, - taking into account realistic models for adversary (side-channels...). By the end of the thesis we have enhanced a theoretical framework and computing tools helping verifying cryptographic protocols
Venelli, Alexandre. „Contribution à la sécurite physique des cryptosystèmes embarqués“. Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22005/document.
Der volle Inhalt der QuelleThis thesis focuses on the study of side-channel attacks as well as their consequences on the secure implementation of cryptographic algorithms. We first analyze different side-channel attacks and we propose an improvement of a particularly interesting generic attack: the mutual information analysis. We study the effect of state of the art entropy estimation techniques on the results of the attack. We propose the use of B-spline funtions as estimators as they are well suited to the side-channel attack scenario. We also investigate the consequences of this kind of attack on a well known symmetric cryptosystem, the Advanced Encryption Standard (AES), and we propose a countermeasure based on the algebraic structure of AES. The main operation of ECC is the scalar multiplication that consists of adding an elliptic curve point to itself a certain number of times. In the second part, we investigate how to secure this operation. We propose a scalar multiplication algorithm that is both efficient and secure against main side-channel attacks. We then study pairings, a mathematical construction based on elliptic curves. Pairings have many interesting properties that allow the creation of new cryptographic protocols. We finally evaluate the side-channel resistance of pairings
Andouard, Philippe. „Outils d'aide à la recherche de vulnérabilités dans l'implantation d'applications embarquées sur carte à puce“. Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13958/document.
Der volle Inhalt der QuelleThe work presented in this thesis aims at easing the evaluation process of smartcards embedded software. On one hand, we set up a software environment dedicated to analyze the implementation resistance of cryptographic to power analysis attacks. This environment must be seen as a tool that facilitates a real attack by giving a way to find information leakages in an implementation. On the other hand, we focused on analyzing program written in AVR assembly language in order to check whether they are vulnerable to timing attacks. To achieve this goal we have developed a tool that makes possible the description of a path in the control flow of the program thanks to regular expressions. Those regular expressions will be interpreted by our tool in order to give the exact execution timing (expressed in clock cycles). Finally, we studied how to ease the global comprehension of a program written in C language in order to check whether security policies are well implemented. First, we provide graphical navigation assisants that helps to understand the progam being analyzed by giving information on variables and procedures. Then, we provide a way to check the security policies through the use of requests expressed with the CTL logic. This approach does not need prior modelisation of the program
Barki, Amira. „Mécanismes cryptographiques conciliant authentification et respect de la vie privée dans le contexte du M2M“. Thesis, Compiègne, 2016. http://www.theses.fr/2016COMP2337.
Der volle Inhalt der QuelleMachine to Machine (M2M) applications enable a better management of resources and provide users With greater cornfort. Unfortunately, they also entail serious security and privacy concerns. ln this thesis, we focus on M2M security, and particularly on the authentication and privacy issues of M2M applications involving a SIM card. ln the first part, we design five new cryptographic primitives and formally prove that they meet the expected security requirements. More precisely, they consist of a partially blind signature scheme, a sequential aggregate Message Authentication Codes (MAC) scheme, an algebraic MAC scheme and two pre-Direct Anonymous Attestation (pre-DAA) schemes. Some of the proposed schemes aim to achieve a particular property that was not provided by previous constructions whereas others intend to improve the efficiency of state-of-the-art schemes. Our five schemes do not require the userls device to compute pairings. Thus, they are suitable for resource constrained environments such as SIM cards. ln a second part, we rely on these primitives to propose new privacy-preserving protocols. More specifically, we design an efficient private eCash system. We also propose a protocol enabling anonymous authentication and identification of embedded SIMs (eSlMs). Furthermore, we rely on our algebraic MAC scheme to build a practical Keyed-Verification Anonymous Credentials (KVAC) system. Finally, based on our sequential aggregate MAC scheme, we introduce a remote electronic voting system that is coercion-resistant and practical for real polls. The security of our protocols is formally proven in the Random Oracle Model (ROM) under classical computational assumptions
Dehbaoui, Amine. „Analyse Sécuritaire des Émanations Électromagnétiques des Circuits Intégrés“. Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20020.
Der volle Inhalt der QuelleThe integration of cryptographic primitives in different electronic devices is widely used today incommunications, financial services, government services or PayTV.Foremost among these devices include the smart card. According to a report published in August 2010, IMS Research forecasts that the smart card market will reach 5.8 billion units sold in this year. The vast majority is used in telecommunications (SIM) and banking.The smart card incorporates an integrated circuit which can be a dedicated processor for cryptographic calculations. Therefore, these integrated circuits contain secrets such as secret or private keys used by the symmetric or asymmetric cryptographic algorithms. These keys must remain absolutely confidential to ensure the safety chain.Therefore the robustness of smart cards against attacks is crucial. These attacks can be classifiedinto three main categories: invasive, semi-invasive and non-invasive.Non-invasive attacks can be considered the most dangerous, since this kind of attack can be achieved without any contact with the circuit.Indeed, while using electronic circuits that compose them are subjected to variations in current and voltage. These variations generate an electromagnetic radiation propagating in the vicinity of the circuit.These radiations are correlated with secret information (eg a secret key used for authentication). Several attacks based on these leakages were published by the scientific community.This thesis aims to: (a) understand the different sources of electromagnetic emanations of integrated circuits, and propose a localized near field attack to test the robustness of a cryptographic circuit and (b) propose counter-measures to these attacks
Ruhault, Sylvain. „Security analysis for pseudo-random number generators“. Thesis, Paris, Ecole normale supérieure, 2015. http://www.theses.fr/2015ENSU0014/document.
Der volle Inhalt der QuelleIn cryptography, randomness plays an important role in multiple applications. It is required in fundamental tasks such as key generation and initialization vectors generation or in key exchange. The security of these cryptographic algorithms and protocols relies on a source of unbiased and uniform distributed random bits. Cryptography practitioners usually assume that parties have access to perfect randomness. However, quite often this assumption is not realizable in practice and random bits are generated by a Pseudo-Random Number Generator. When this is done, the security of the scheme depends of course in a crucial way on the quality of the (pseudo-)randomness generated. However, only few generators used in practice have been analyzed and therefore practitioners and end users cannot easily assess their real security level. We provide in this thesis security models for the assessment of pseudo-random number generators and we propose secure constructions. In particular, we propose a new definition of robustness and we extend it to capture memory attacks and side-channel attacks. On a practical side, we provide a security assessment of generators used in practice, embedded in system kernel (Linux /dev/random) and cryptographic libraries (OpenSSL and Java SecureRandom), and we prove that these generators contain potential vulnerabilities