49 research outputs found

    A survey of defense mechanisms against distributed denial of service (DDOS) flooding attacks

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    Distributed Denial of Service (DDoS) flooding attacks are one of the biggest concerns for security professionals. DDoS flooding attacks are typically explicit attempts to disrupt legitimate users' access to services. Attackers usually gain access to a large number of computers by exploiting their vulnerabilities to set up attack armies (i.e., Botnets). Once an attack army has been set up, an attacker can invoke a coordinated, large-scale attack against one or more targets. Developing a comprehensive defense mechanism against identified and anticipated DDoS flooding attacks is a desired goal of the intrusion detection and prevention research community. However, the development of such a mechanism requires a comprehensive understanding of the problem and the techniques that have been used thus far in preventing, detecting, and responding to various DDoS flooding attacks. In this paper, we explore the scope of the DDoS flooding attack problem and attempts to combat it. We categorize the DDoS flooding attacks and classify existing countermeasures based on where and when they prevent, detect, and respond to the DDoS flooding attacks. Moreover, we highlight the need for a comprehensive distributed and collaborative defense approach. Our primary intention for this work is to stimulate the research community into developing creative, effective, efficient, and comprehensive prevention, detection, and response mechanisms that address the DDoS flooding problem before, during and after an actual attack. © 1998-2012 IEEE

    Revised reference model

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    This document contains an update of the HIDENETS Reference Model, whose preliminary version was introduced in D1.1. The Reference Model contains the overall approach to development and assessment of end-to-end resilience solutions. As such, it presents a framework, which due to its abstraction level is not only restricted to the HIDENETS car-to-car and car-to-infrastructure applications and use-cases. Starting from a condensed summary of the used dependability terminology, the network architecture containing the ad hoc and infrastructure domain and the definition of the main networking elements together with the software architecture of the mobile nodes is presented. The concept of architectural hybridization and its inclusion in HIDENETS-like dependability solutions is described subsequently. A set of communication and middleware level services following the architecture hybridization concept and motivated by the dependability and resilience challenges raised by HIDENETS-like scenarios is then described. Besides architecture solutions, the reference model addresses the assessment of dependability solutions in HIDENETS-like scenarios using quantitative evaluations, realized by a combination of top-down and bottom-up modelling, as well as verification via test scenarios. In order to allow for fault prevention in the software development phase of HIDENETS-like applications, generic UML-based modelling approaches with focus on dependability related aspects are described. The HIDENETS reference model provides the framework in which the detailed solution in the HIDENETS project are being developed, while at the same time facilitating the same task for non-vehicular scenarios and application

    Wide-Area Situation Awareness based on a Secure Interconnection between Cyber-Physical Control Systems

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    Posteriormente, examinamos e identificamos los requisitos especiales que limitan el diseño y la operación de una arquitectura de interoperabilidad segura para los SSC (particularmente los SCCF) del smart grid. Nos enfocamos en modelar requisitos no funcionales que dan forma a esta infraestructura, siguiendo la metodología NFR para extraer requisitos esenciales, técnicas para la satisfacción de los requisitos y métricas para nuestro modelo arquitectural. Estudiamos los servicios necesarios para la interoperabilidad segura de los SSC del SG revisando en profundidad los mecanismos de seguridad, desde los servicios básicos hasta los procedimientos avanzados capaces de hacer frente a las amenazas sofisticadas contra los sistemas de control, como son los sistemas de detección, protección y respuesta ante intrusiones. Nuestro análisis se divide en diferentes áreas: prevención, consciencia y reacción, y restauración; las cuales general un modelo de seguridad robusto para la protección de los sistemas críticos. Proporcionamos el diseño para un modelo arquitectural para la interoperabilidad segura y la interconexión de los SCCF del smart grid. Este escenario contempla la interconectividad de una federación de proveedores de energía del SG, que interactúan a través de la plataforma de interoperabilidad segura para gestionar y controlar sus infraestructuras de forma cooperativa. La plataforma tiene en cuenta las características inherentes y los nuevos servicios y tecnologías que acompañan al movimiento de la Industria 4.0. Por último, presentamos una prueba de concepto de nuestro modelo arquitectural, el cual ayuda a validar el diseño propuesto a través de experimentaciones. Creamos un conjunto de casos de validación que prueban algunas de las funcionalidades principales ofrecidas por la arquitectura diseñada para la interoperabilidad segura, proporcionando información sobre su rendimiento y capacidades.Las infraestructuras críticas (IICC) modernas son vastos sistemas altamente complejos, que precisan del uso de las tecnologías de la información para gestionar, controlar y monitorizar el funcionamiento de estas infraestructuras. Debido a sus funciones esenciales, la protección y seguridad de las infraestructuras críticas y, por tanto, de sus sistemas de control, se ha convertido en una tarea prioritaria para las diversas instituciones gubernamentales y académicas a nivel mundial. La interoperabilidad de las IICC, en especial de sus sistemas de control (SSC), se convierte en una característica clave para que estos sistemas sean capaces de coordinarse y realizar tareas de control y seguridad de forma cooperativa. El objetivo de esta tesis se centra, por tanto, en proporcionar herramientas para la interoperabilidad segura de los diferentes SSC, especialmente los sistemas de control ciber-físicos (SCCF), de forma que se potencie la intercomunicación y coordinación entre ellos para crear un entorno en el que las diversas infraestructuras puedan realizar tareas de control y seguridad cooperativas, creando una plataforma de interoperabilidad segura capaz de dar servicio a diversas IICC, en un entorno de consciencia situacional (del inglés situational awareness) de alto espectro o área (wide-area). Para ello, en primer lugar, revisamos las amenazas de carácter más sofisticado que amenazan la operación de los sistemas críticos, particularmente enfocándonos en los ciberataques camuflados (del inglés stealth) que amenazan los sistemas de control de infraestructuras críticas como el smart grid. Enfocamos nuestra investigación al análisis y comprensión de este nuevo tipo de ataques que aparece contra los sistemas críticos, y a las posibles contramedidas y herramientas para mitigar los efectos de estos ataques

    Proceedings of The 13. Nordic Workshop on Secure IT Systems, NordSec 2008, Kongens Lyngby Oct 9-10, 2008

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    Optimization of Handover, Survivability, Multi-Connectivity and Secure Slicing in 5G Cellular Networks using Matrix Exponential Models and Machine Learning

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    Title from PDF of title page, viewed January 31, 2023Dissertation advisor: Cory BeardVitaIncludes bibliographical references (pages 173-194)Dissertation (Ph.D.)--Department of Computer Science and Electrical Engineering. University of Missouri--Kansas City, 2022This works proposes optimization of cellular handovers, cellular network survivability modeling, multi-connectivity and secure network slicing using matrix exponentials and machine learning techniques. We propose matrix exponential (ME) modeling of handover arrivals with the potential to much more accurately characterize arrivals and prioritize resource allocation for handovers, especially handovers for emergency or public safety needs. With the use of a ‘B’ matrix for representing a handover arrival, we have a rich set of dimensions to model system handover behavior. We can study multiple parameters and the interactions between system events along with the user mobility, which would trigger a handoff in any given scenario. Additionally, unlike any traditional handover improvement scheme, we develop a ‘Deep-Mobility’ model by implementing a deep learning neural network (DLNN) to manage network mobility, utilizing in-network deep learning and prediction. We use the radio and the network key performance indicators (KPIs) to train our model to analyze network traffic and handover requirements. Cellular network design must incorporate disaster response, recovery and repair scenarios. Requirements for high reliability and low latency often fail to incorporate network survivability for mission critical and emergency services. Our Matrix Exponential (ME) model shows how survivable networks can be designed based on controlling numbers of crews, times taken for individual repair stages, and the balance between fast and slow repairs. Transient and the steady state representations of system repair models, namely, fast and slow repairs for networks consisting of multiple repair crews have been analyzed. Failures are exponentially modeled as per common practice, but ME distributions describe the more complex recovery processes. In some mission critical communications, the availability requirements may exceed five or even six nines (99.9999%). To meet such a critical requirement and minimize the impact of mobility during handover, a Fade Duration Outage Probability (FDOP) based multiple radio link connectivity handover method has been proposed. By applying such a method, a high degree of availability can be achieved by utilizing two or more uncorrelated links based on minimum FDOP values. Packet duplication (PD) via multi-connectivity is a method of compensating for lost packets on a wireless channel. Utilizing two or more uncorrelated links, a high degree of availability can be attained with this strategy. However, complete packet duplication is inefficient and frequently unnecessary. We provide a novel adaptive fractional packet duplication (A-FPD) mechanism for enabling and disabling packet duplication based on a variety of parameters. We have developed a ‘DeepSlice’ model by implementing Deep Learning (DL) Neural Network to manage network load efficiency and network availability, utilizing in-network deep learning and prediction. Our Neural Network based ‘Secure5G’ Network Slicing model will proactively detect and eliminate threats based on incoming connections before they infest the 5G core network elements. These will enable the network operators to sell network slicing as-a-service to serve diverse services efficiently over a single infrastructure with higher level of security and reliability.Introduction -- Matrix exponential and deep learning neural network modeling of cellular handovers -- Survivability modeling in cellular networks -- Multi connectivity based handover enhancement and adaptive fractional packet duplication in 5G cellular networks -- Deepslice and Secure5G: a deep learning framework towards an efficient, reliable and secure network slicing in 5G networks -- Conclusion and future scop

    A Quality-Driven Approach to Enable Decision-Making in Self-Adaptive Software

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    Self-adaptive software systems are increasingly in demand. The driving forces are changes in the software “self” and “context”, particularly in distributed and pervasive applications. These systems provide self-* properties in order to keep requirements satisfied in different situations. Engineering self-adaptive software normally involves building the adaptable software and the adaptation manager. This PhD thesis focuses on the latter, especially on the design and implementation of the deciding process in an adaptation manager. For this purpose, a Quality-driven Framework for Engineering an Adaptation Manager (QFeam) is proposed, in which quality requirements play a key role as adaptation goals. Two major phases of QFeam are building the runtime adaptation model and designing the adaptation mechanism. The modeling phase investigates eliciting and specifying key entities of the adaptation problem space including goals, attributes, and actions. Three composition patterns are discussed to link these entities to build the adaptation model, namely: goal-centric, attribute-action-coupling, and hybrid patterns. In the second phase, the adaptation mechanism is designed according to the adopted pattern in the model. Therefore, three categories of mechanisms are discussed, in which the novel goal-ensemble mechanism is introduced. A concrete model and mechanism, the Goal-Attribute-Action Model (GAAM), is proposed based on the goal-centric pattern and the goal-ensemble mechanism. GAAM is implemented based on the StarMX framework for Java-based systems. Several considerations are taken into account in QFeam: i) the separation of adaptation knowledge from application knowledge, ii) highlighting the role of adaptation goals, and iii) modularity and reusability. Among these, emphasizing goals is the tenet of QFeam, especially in order to address the challenge of addressing several self- * properties in the adaptation manager. Furthermore, QFeam aims at embedding a model in the adaptation manager, particularly in the goal-centric and hybrid patterns. The proposed framework focuses on mission-critical systems including enterprise and service-oriented applications. Several empirical studies were conducted to put QFeam into practice, and also evaluate GAAM in comparison with other adaptation models and mechanisms. Three case studies were selected for this purpose: the TPC-W bookstore application, a news application, and the CC2 VoIP call controller. Several research questions were set for each case study, and findings indicate that the goal-ensemble mechanism and GAAM can outperform or work as well as a common rule-based approach. The notable difference is that the effort of building an adaptation manager based on a goal-centric pattern is less than building it using an attribute-action-coupling pattern. Moreover, representing goals explicitly leads to better scalability and understandability of the adaptation manager. Overall, the experience of working on these three systems show that QFeam improves the design and development process of the adaptation manager, particularly by highlighting the role of adaptation goals

    The 1st International Conference on Computational Engineering and Intelligent Systems

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    Computational engineering, artificial intelligence and smart systems constitute a hot multidisciplinary topic contrasting computer science, engineering and applied mathematics that created a variety of fascinating intelligent systems. Computational engineering encloses fundamental engineering and science blended with the advanced knowledge of mathematics, algorithms and computer languages. It is concerned with the modeling and simulation of complex systems and data processing methods. Computing and artificial intelligence lead to smart systems that are advanced machines designed to fulfill certain specifications. This proceedings book is a collection of papers presented at the first International Conference on Computational Engineering and Intelligent Systems (ICCEIS2021), held online in the period December 10-12, 2021. The collection offers a wide scope of engineering topics, including smart grids, intelligent control, artificial intelligence, optimization, microelectronics and telecommunication systems. The contributions included in this book are of high quality, present details concerning the topics in a succinct way, and can be used as excellent reference and support for readers regarding the field of computational engineering, artificial intelligence and smart system

    Quantitative Evaluation and Reevaluation of Security in Services

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    Services are software components or systems designed to support interoperable machine or application-oriented interaction over a network. The popularity of services grows because they are easily accessible, very flexible, provide reach functionality, and can constitute more complex services. During the service selection, the user considers not only functional requirements to a service but also security requirements. The user would like to be aware that security of the service satisfies security requirements before starting the exploitation of the service, i.e., before the service is granted to access assets of the user. Moreover, the user wants to be sure that security of the service satisfies security requirements during the exploitation which may last for a long period. Pursuing these two goals require security of the service to be evaluated before the exploitation and continuously reevaluated during the exploitation. This thesis aims at a framework consisting of several quantitative methods for evaluation and continuous reevaluation of security in services. The methods should help a user to select a service and to control the service security level during the exploitation. The thesis starts with the formal model for general quantitative security metrics and for risk that may be used for the evaluation of security in services. Next, we adjust the computation of security metrics with a refined model of an attacker. Then, the thesis proposes a general method for the evaluation of security of a complex service composed from several simple services using different security metrics. The method helps to select the most secure design of the complex service. In addition, the thesis describes an approach based on the Usage Control (UCON) model for continuous reevaluation of security in services. Finally, the thesis discusses several strategies for a cost-effective decision making in the UCON unde

    Radio Communications

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    In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modified our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the field of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks
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