77 research outputs found

    A framework for development and implementation of secure hardware-based systems

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    Orientador : Ricardo Dahab.Tese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo A concepção de sistemas seguros demanda tratamento holístico, global. A razão é que a mera composição de componentes individualmente seguros não garante a segurança do conjunto resultante2. Enquanto isso, a complexidade dos sistemas de informação cresce vigorosamente, dentre outros, no que se diz respeito: i) ao número de componentes constituintes; ii) ao número de interações com outros sistemas; e iii) 'a diversidade de natureza dos componentes. Este crescimento constante da complexidade demanda um domínio de conhecimento ao mesmo tempo multidisciplinar e profundo, cada vez mais difícil de ser coordenado em uma única visão global, seja por um indivíduo, seja por uma equipe de desenvolvimento. Nesta tese propomos um framework para a concepção, desenvolvimento e deployment de sistemas baseados em hardware que é fundamentado em uma visão única e global de segurança. Tal visão cobre um espectro abrangente de requisitos, desde a integridade física dos dispositivos até a verificação, pelo usuário final, de que seu sistema está logicamente íntegro. Para alcançar este objetivo, apresentamos nesta tese o seguinte conjunto de componentes para o nosso framework: i) um conjunto de considerações para a construção de modelos de ataques que capturem a natureza particular dos adversários de sistemas seguros reais, principalmente daqueles baseados em hardware; ii) um arcabouço teórico com conceitos e definições importantes e úteis na construção de sistemas seguros baseados em hardware; iii) um conjunto de padrões (patterns) de componentes e arquiteturas de sistemas seguros baseados em hardware; iv) um modelo teórico, lógico-probabilístico, para avaliação do nível de segurança das arquiteturas e implementações; e v) a aplicação dos elementos do framework na implementação de sistemas de produção, com estudos de casos muito significativos3. Os resultados relacionados a estes componentes estão apresentados nesta tese na forma de coletânea de artigos. 2 Técnicas "greedy" não fornecem necessariamente os resultados ótimos. Mais, a presença de componentes seguros não é nem fundamental. 3 Em termos de impacto social, econômico ou estratégicoAbstract: The conception of secure systems requires a global, holistic, approach. The reason is that the mere composition of individually secure components does not necessarily imply in the security of the resulting system4. Meanwhile, the complexity of information systems has grown vigorously in several dimensions as: i) the number of components, ii) the number of interactions with other components, iii) the diversity in the nature of the components. This continuous growth of complexity requires from designers a deep and broad multidisciplinary knowledge, which is becoming increasingly difficult to be coordinated and attained either by individuals or even teams. In this thesis we propose a framework for the conception, development, and deployment of secure hardware-based systems that is rooted on a unified and global security vision. Such a vision encompasses a broad spectrum of requirements, from device physical integrity to the device logical integrity verification by humans. In order to attain this objective we present in this thesis the following set of components of our framework: i) a set of considerations for the development of threat models that captures the particular nature of adversaries of real secure systems based on hardware; ii) a set of theoretical concepts and definitions useful in the design of secure hardware-based systems; iii) a set of design patterns of components and architectures for secure systems; iv) a logical-probabilistic theoretical model for security evaluation of system architectures and implementations; and v) the application of the elements of our framework in production systems with highly relevant study cases. Our results related to these components are presented in this thesis as a series of papers which have been published or submitted for publication. 4Greedy techniques do not inevitably yield optimal results. More than that, the usage of secure components is not even requiredDoutoradoCiência da ComputaçãoDoutor em Ciência da Computaçã

    The 1991 3rd NASA Symposium on VLSI Design

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    Papers from the symposium are presented from the following sessions: (1) featured presentations 1; (2) very large scale integration (VLSI) circuit design; (3) VLSI architecture 1; (4) featured presentations 2; (5) neural networks; (6) VLSI architectures 2; (7) featured presentations 3; (8) verification 1; (9) analog design; (10) verification 2; (11) design innovations 1; (12) asynchronous design; and (13) design innovations 2

    Multi-Quality Auto-Tuning by Contract Negotiation

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    A characteristic challenge of software development is the management of omnipresent change. Classically, this constant change is driven by customers changing their requirements. The wish to optimally leverage available resources opens another source of change: the software systems environment. Software is tailored to specific platforms (e.g., hardware architectures) resulting in many variants of the same software optimized for different environments. If the environment changes, a different variant is to be used, i.e., the system has to reconfigure to the variant optimized for the arisen situation. The automation of such adjustments is subject to the research community of self-adaptive systems. The basic principle is a control loop, as known from control theory. The system (and environment) is continuously monitored, the collected data is analyzed and decisions for or against a reconfiguration are computed and realized. Central problems in this field, which are addressed in this thesis, are the management of interdependencies between non-functional properties of the system, the handling of multiple criteria subject to decision making and the scalability. In this thesis, a novel approach to self-adaptive software--Multi-Quality Auto-Tuning (MQuAT)--is presented, which provides design and operation principles for software systems which automatically provide the best possible utility to the user while producing the least possible cost. For this purpose, a component model has been developed, enabling the software developer to design and implement self-optimizing software systems in a model-driven way. This component model allows for the specification of the structure as well as the behavior of the system and is capable of covering the runtime state of the system. The notion of quality contracts is utilized to cover the non-functional behavior and, especially, the dependencies between non-functional properties of the system. At runtime the component model covers the runtime state of the system. This runtime model is used in combination with the contracts to generate optimization problems in different formalisms (Integer Linear Programming (ILP), Pseudo-Boolean Optimization (PBO), Ant Colony Optimization (ACO) and Multi-Objective Integer Linear Programming (MOILP)). Standard solvers are applied to derive solutions to these problems, which represent reconfiguration decisions, if the identified configuration differs from the current. Each approach is empirically evaluated in terms of its scalability showing the feasibility of all approaches, except for ACO, the superiority of ILP over PBO and the limits of all approaches: 100 component types for ILP, 30 for PBO, 10 for ACO and 30 for 2-objective MOILP. In presence of more than two objective functions the MOILP approach is shown to be infeasible

    The Virtual Bus: A Network Architecture Designed to Support Modular-Redundant Distributed Periodic Real-Time Control Systems

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    The Virtual Bus network architecture uses physical layer switching and a combination of space- and time-division multiplexing to link segments of a partial mesh network together on schedule to temporarily form contention-free multi-hop, multi-drop simplex signalling paths, or 'virtual buses'. Network resources are scheduled and routed by a dynamic distributed resource allocation mechanism with self-forming and self-healing characteristics. Multiple virtual buses can coexist simultaneously in a single network, as the resources allocated to each bus are orthogonal in either space or time. The Virtual Bus architecture achieves deterministic delivery times for time-sensitive traffic over multi-hop partial mesh networks by employing true line-speed switching; delays of around 15ns at each switching point are demonstrated experimentally, and further reductions in switching delays are shown to be achievable. Virtual buses are inherently multicast, with delivery skew across multiple destinations proportional to the difference in equivalent physical length to each destination. The Virtual Bus architecture is not a purely theoretical concept; a small research platform has been constructed for development, testing and demonstration purposes

    Energy-Aware Data Management on NUMA Architectures

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    The ever-increasing need for more computing and data processing power demands for a continuous and rapid growth of power-hungry data center capacities all over the world. As a first study in 2008 revealed, energy consumption of such data centers is becoming a critical problem, since their power consumption is about to double every 5 years. However, a recently (2016) released follow-up study points out that this threatening trend was dramatically throttled within the past years, due to the increased energy efficiency actions taken by data center operators. Furthermore, the authors of the study emphasize that making and keeping data centers energy-efficient is a continuous task, because more and more computing power is demanded from the same or an even lower energy budget, and that this threatening energy consumption trend will resume as soon as energy efficiency research efforts and its market adoption are reduced. An important class of applications running in data centers are data management systems, which are a fundamental component of nearly every application stack. While those systems were traditionally designed as disk-based databases that are optimized for keeping disk accesses as low a possible, modern state-of-the-art database systems are main memory-centric and store the entire data pool in the main memory, which replaces the disk as main bottleneck. To scale up such in-memory database systems, non-uniform memory access (NUMA) hardware architectures are employed that face a decreased bandwidth and an increased latency when accessing remote memory compared to the local memory. In this thesis, we investigate energy awareness aspects of large scale-up NUMA systems in the context of in-memory data management systems. To do so, we pick up the idea of a fine-grained data-oriented architecture and improve the concept in a way that it keeps pace with increased absolute performance numbers of a pure in-memory DBMS and scales up on NUMA systems in the large scale. To achieve this goal, we design and build ERIS, the first scale-up in-memory data management system that is designed from scratch to implement a data-oriented architecture. With the help of the ERIS platform, we explore our novel core concept for energy awareness, which is Energy Awareness by Adaptivity. The concept describes that software and especially database systems have to quickly respond to environmental changes (i.e., workload changes) by adapting themselves to enter a state of low energy consumption. We present the hierarchically organized Energy-Control Loop (ECL), which is a reactive control loop and provides two concrete implementations of our Energy Awareness by Adaptivity concept, namely the hardware-centric Resource Adaptivity and the software-centric Storage Adaptivity. Finally, we will give an exhaustive evaluation regarding the scalability of ERIS as well as our adaptivity facilities

    Advances in Grid Computing

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    This book approaches the grid computing with a perspective on the latest achievements in the field, providing an insight into the current research trends and advances, and presenting a large range of innovative research papers. The topics covered in this book include resource and data management, grid architectures and development, and grid-enabled applications. New ideas employing heuristic methods from swarm intelligence or genetic algorithm and quantum encryption are considered in order to explain two main aspects of grid computing: resource management and data management. The book addresses also some aspects of grid computing that regard architecture and development, and includes a diverse range of applications for grid computing, including possible human grid computing system, simulation of the fusion reaction, ubiquitous healthcare service provisioning and complex water systems

    NASA Tech Briefs, September 1997

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    Topics include: Data Acquisition and Analysis; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Software; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences

    2013-2014, University of Memphis bulletin

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    University of Memphis bulletin containing the graduate catalog for 2013-2014.https://digitalcommons.memphis.edu/speccoll-ua-pub-bulletins/1434/thumbnail.jp
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