68 research outputs found

    YOLO: Accélération du temps de démarrage de la machine virtuelleen réduisant les opérations d’I/O

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    Several works have shown that the time to boot one virtual machine (VM) can last up to a fewminutes in high consolidated cloud scenarios. This time is critical as VM boot duration defines how anapplication can react w.r.t. demands’ fluctuations (horizontal elasticity). To limit as much as possible thetime to boot a VM, we design the YOLO mechanism (You Only Load Once). YOLO optimizes the numberof I/O operations generated during a VM boot process by relying on the boot image abstraction, a subsetof the VM image (VMI) that contains data blocks necessary to complete the boot operation. Whenevera VM is booted, YOLO intercepts all read accesses and serves them directly from the boot image, whichhas been locally stored on fast access storage devices (e.g., memory, SSD, etc.). Creating boot imagesfor 900+ VMIs from Google Cloud shows that only 40 GB is needed to store all the mandatory data.Experiments show that YOLO can speed up VM boot duration 2-13 times under different resourcescontention with a negligible overhead on the I/O path. Finally, we underline that although YOLO hasbeen validated with a KVM environment, it does not require any modification on the hypervisor, theguest kernel nor the VM image (VMI) structure and can be used for several kinds of VMIs (in this study,Linux and Windows VMIs have been tested)Plusieurs travaux ont montré que le temps de démarrage d’une machine virtuelle (VM)peut s’étale sur plusieurs minutes dans des scénarios fortement consolidés. Ce délai est critique car ladurée de démarrage d’une VM définit la réactivité d’une application en fonction des fluctuations decharge (élasticité horizontale). Pour limiter au maximum le temps de démarrage d’une VM, nous avonsconçu le mécanisme YOLO (You Only Load Once). YOLO optimise le nombre d’opérations “disque”générées pendant le processus de démarrage. Pour ce faire, il s’appuie sur une nouvelle abstractionintitulée “image de démarrage” et correspondant à un sous-ensemble des données de l’image de la VM.Chaque fois qu’une machine virtuelle est démarrée, YOLO intercepte l’ensemble des accès en lectureafin de les satisfaire directement à partir de l’image de démarrage, qui a été stockée préalablement surdes périphériques de stockage à accès rapide (par exemple, mémoire, SSD, etc.). La création d’imagede démarrage pour les 900 types des VMs proposées sur l’infrastructure Cloud de Google représenteseulement 40 Go, ce qui est une quantité de données qui peut tout à fait être stockée sur chacundes noeuds de calculs. Les expériences réalisées montrent que YOLO permet accélérer la durée dedémarrage d’un facteur allant de 2 à 13 selon les différents scénarios de consolidation. Nous soulignonsque bien que YOLO ait été validé avec un environnement KVM, il ne nécessite aucune modificatfionsur l’hyperviseur, le noyau invité ou la structure d’image de la VM et peut donc être utilisé pourplusieurs types d’images (dans cette étude, nous testons des images Linux et Windows)

    An innovative approach to performance metrics calculus in cloud computing environments: a guest-to-host oriented perspective

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    In virtualized systems, the task of profiling and resource monitoring is not straight-forward. Many datacenters perform CPU overcommittment using hypervisors, running multiple virtual machines on a single computer where the total number of virtual CPUs exceeds the total number of physical CPUs available. From a customer point of view, it could be indeed interesting to know if the purchased service levels are effectively respected by the cloud provider. The innovative approach to performance profiling described in this work is based on the use of virtual performance counters, only recently made available by some hypervisors to their virtual machines, to implement guest-wide profiling. Although it isn't possible for the virtual machine to access Virtual Machine Monitor, with this method it is able to gather interesting informations to deduce the state of resource overcommittment of the virtualization host where it is executed. Tests have been carried out inside the compute nodes of FIWARE Genoa Node, an instance of a widely distributed federated community cloud, based on OpenStack and KVM. AgiLab-DITEN, the laboratory I belonged to and where I conducted my studies, together with TnT-Lab\u2013DITEN and CNIT-GE-Unit designed, installed and configured the whole Genoa Node, that was hosted on DITEN-UniGE equipment rooms. All the software measuring instruments, operating systems and programs used in this research are publicly available and free, and can be easily installed in a micro instance of virtual machine, rapidly deployable also in public clouds

    Improving the robustness and privacy of HTTP cookie-based tracking systems within an affiliate marketing context : a thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University, Albany, New Zealand

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    E-commerce activities provide a global reach for enterprises large and small. Third parties generate visitor traffic for a fee; through affiliate marketing, search engine marketing, keyword bidding and through organic search, amongst others. Therefore, improving the robustness of the underlying tracking and state management techniques is a vital requirement for the growth and stability of e-commerce. In an inherently stateless ecosystem such as the Internet, HTTP cookies have been the de-facto tracking vector for decades. In a previous study, the thesis author exposed circumstances under which cookie-based tracking system can fail, some due to technical glitches, others due to manipulations made for monetary gain by some fraudulent actors. Following a design science research paradigm, this research explores alternative tracking vectors discussed in previous research studies within a cross-domain tracking environment. It evaluates their efficacy within current context and demonstrates how to use them to improve the robustness of existing tracking techniques. Research outputs include methods, instantiations and a privacy model artefact based on information seeking behaviour of different categories of tracking software, and their resulting privacy intrusion levels. This privacy model provides clarity and is useful for practitioners and regulators to create regulatory frameworks that do not hinder technological advancement, rather they curtail privacy-intrusive tracking practices on the Internet. The method artefacts are instantiated as functional prototypes, available publicly on Internet, to demonstrate the efficacy and utility of the methods through live tests. The research contributes to the theoretical knowledge base through generalisation of empirical findings and to the industry by problem solving design artefacts

    Developmental Flight Test Lessons Learned from Open Architecture Software in the Mission Computer of the U.S. Navy E-2C Group II Aircraft

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    The Naval Air Systems Command commissioned the E-2C Hawkeye Group II Mission Computer Replacement Program and tasked Air Test and Evaluation Squadron Two-Zero and the E-2C Integrated Test Team to evaluate the integration of the form, fit, and function of the OL-698/ASQ Mission Computer Replacement (MCR) for replacement of the Litton L-304 Mission Computer in the E-2C Group II configured aircraft. As part of the life cycle support of the E-2C aircraft, the MCR configuration fields a new, more reliable Commercial-off-the-Shelf (COTS) hardware system and preserves the original software investment by emulating the existing Litton Instructional Set Architecture (LISA) legacy code. Incorporating Northrop Grumman Space Technology’s Reconfigurable Processor for Legacy Applications Code Execution (RePLACE) software re-hosting technique, the investment in the LISA software is maintained. Conducting developmental test of robust software systems, such as the MCR and its associated software, provided dramatically different challenges than traditional developmental testing. A series of lessons were learned through particular discrepancies and deficiencies discovered through the six month flight test period. Specific deficiencies illustrate where proper planning could ease the difficulties encountered in software testing. Keys to successful developmental software tests include having the appropriate personnel on the test team with the proper equipment and capability. Equally important, inadequate configuration management creates more problems than fixes. Software re-programming can provide faster fixes than traditional developmental test. The flexibility of software programming makes configuration management a challenge as multiple versions become available in a short amount of time. Multiple versions of software heighten the risk of configuration management breakdown during limited amount of available flight tests. Each re-programmed version potentially fixes targeted deficiencies, but can also cause new issues in functional areas already tested. Inherently, regression testing impacts the schedule. Software testing requires a realistic schedule that the author believes should compensate for anticipated problems. Data collection, reduction, and analysis always prove to be valuable in developmental testing. A solid instrumentation plan for data collection from all parties involved in flight tests, especially data link network tests, are critical for trouble shooting discovered deficiencies. Software testing is relatively new to the developmental test world and can be seen as the way of the future. Software upgrades lure program managers into a potentially cost effective option in the face of aging avionics systems. With realistic planning and configuration management, the cost and performance effectiveness of software upgrades and development is more likely to become realized

    IoTsafe, Decoupling Security from Applications for a Safer IoT

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    The use of robust security solutions is a must for the Internet of Things (IoT) devices and their applications: regulators in different countries are creating frameworks for certifying those devices with an acceptable security level. However, even for already certified devices, security protocols have to be updated when a breach is found or a certain version becomes obsolete. Many approaches for securing IoT applications are nowadays based on the integration of a security layer [e.g., using transport layer security, (TLS)], but this may result in difficulties when upgrading the security algorithms, as the whole application has to be updated. This fact may shorten the life of IoT devices. As a way to overcome these difficulties, this paper presents IoTsafe, a novel approach relying on secure socket shell (SSH), a feasible alternative to secure communications in IoT applications based on hypertext transfer protocol (HTTP and HTTP/2). In order to illustrate its advantages, a comparison between the traditional approach (HTTP with TLS) and our scheme (HTTP with SSH) is performed over low-power wireless personal area networks (6loWPAN) through 802.15.4 interfaces. The results show that the proposed approach not only provides a more robust and easy-To-update solution, but it also brings an improvement to the overall performance in terms of goodput and energy consumption. Core server stress tests are also presented, and the server performance is also analyzed in terms of RAM consumption and escalation strategies

    A Survey and Evaluation of Android-Based Malware Evasion Techniques and Detection Frameworks

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    Android platform security is an active area of research where malware detection techniques continuously evolve to identify novel malware and improve the timely and accurate detection of existing malware. Adversaries are constantly in charge of employing innovative techniques to avoid or prolong malware detection effectively. Past studies have shown that malware detection systems are susceptible to evasion attacks where adversaries can successfully bypass the existing security defenses and deliver the malware to the target system without being detected. The evolution of escape-resistant systems is an open research problem. This paper presents a detailed taxonomy and evaluation of Android-based malware evasion techniques deployed to circumvent malware detection. The study characterizes such evasion techniques into two broad categories, polymorphism and metamorphism, and analyses techniques used for stealth malware detection based on the malware’s unique characteristics. Furthermore, the article also presents a qualitative and systematic comparison of evasion detection frameworks and their detection methodologies for Android-based malware. Finally, the survey discusses open-ended questions and potential future directions for continued research in mobile malware detection

    Virtual Organization Clusters: Self-Provisioned Clouds on the Grid

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    Virtual Organization Clusters (VOCs) provide a novel architecture for overlaying dedicated cluster systems on existing grid infrastructures. VOCs provide customized, homogeneous execution environments on a per-Virtual Organization basis, without the cost of physical cluster construction or the overhead of per-job containers. Administrative access and overlay network capabilities are granted to Virtual Organizations (VOs) that choose to implement VOC technology, while the system remains completely transparent to end users and non-participating VOs. Unlike alternative systems that require explicit leases, VOCs are autonomically self-provisioned according to configurable usage policies. As a grid computing architecture, VOCs are designed to be technology agnostic and are implementable by any combination of software and services that follows the Virtual Organization Cluster Model. As demonstrated through simulation testing and evaluation of an implemented prototype, VOCs are a viable mechanism for increasing end-user job compatibility on grid sites. On existing production grids, where jobs are frequently submitted to a small subset of sites and thus experience high queuing delays relative to average job length, the grid-wide addition of VOCs does not adversely affect mean job sojourn time. By load-balancing jobs among grid sites, VOCs can reduce the total amount of queuing on a grid to a level sufficient to counteract the performance overhead introduced by virtualization

    Mobile Authentication with NFC enabled Smartphones

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    Smartphones are becoming increasingly more deployed and as such new possibilities for utilizing the smartphones many capabilities for public and private use are arising. This project will investigate the possibility of using smartphones as a platform for authentication and access control, using near field communication (NFC). To achieve the necessary security for authentication and access control purposes, cryptographic concepts such as public keys, challenge-response and digital signatures are used. To focus the investigation a case study is performed based on the authentication and access control needs of an educational institutions student ID. To gain a more practical understanding of the challenges mobile authentication encounters, a prototype has successfully been developed on the basis of the investigation. The case study performed in this project argues that NFC as a standalone technology is not yet mature to support the advanced communication required by this case. However, combining NFC with other communication technologies such as Bluetooth has proven to be effective. As a result, a general evaluation has been performed on several aspects of the prototype, such as cost-effectiveness, usability, performance and security to evaluate the viability of mobile authentication
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