527 research outputs found

    Towards a formally designed and verified embedded operating system: case study using the B method

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    The dramatic growth in practical applications for iris biometrics has been accompanied by relevant developments in the underlying algorithms and techniques. Along with the research focused on near-infrared images captured with subject cooperation, e orts are being made to minimize the trade-o between the quality of the captured data and the recognition accuracy on less constrained environments, where images are obtained at the visible wavelength, at increased distances, over simpli ed acquisition protocols and adverse lightning conditions. At a rst stage, interpolation e ects on normalization process are addressed, pointing the outcomes in the overall recognition error rates. Secondly, a couple of post-processing steps to the Daugman's approach are performed, attempting to increase its performance in the particular unconstrained environments this thesis assumes. Analysis on both frequency and spatial domains and nally pattern recognition methods are applied in such e orts. This thesis embodies the study on how subject recognition can be achieved, without his cooperation, making use of iris data captured at-a-distance, on-the-move and at visible wavelength conditions. Widely used methods designed for constrained scenarios are analyzed

    Formally designing and implementing cyber security mechanisms in industrial control networks.

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    This dissertation describes progress in the state-of-the-art for developing and deploying formally verified cyber security devices in industrial control networks. It begins by detailing the unique struggles that are faced in industrial control networks and why concepts and technologies developed for securing traditional networks might not be appropriate. It uses these unique struggles and examples of contemporary cyber-attacks targeting control systems to argue that progress in securing control systems is best met with formal verification of systems, their specifications, and their security properties. This dissertation then presents a development process and identifies two technologies, TLA+ and seL4, that can be leveraged to produce a high-assurance embedded security device. The method presented in this dissertation takes an informal design of an embedded device that might be found in a control system and 1) formalizes the design within TLA+, 2) creates and mechanically checks a model built from the formal design, and 3) translates the TLA+ design into a component-based architecture of a native seL4 application. The later chapters of this dissertation describe an application of the process to a security preprocessor embedded device that was designed to add security mechanisms to the network communication of an existing control system. The device and its security properties are formally specified in TLA+ in chapter 4, mechanically checked in chapter 5, and finally its native seL4 architecture is implemented in chapter 6. Finally, the conclusions derived from the research are laid out, as well as some possibilities for expanding the presented method in the future

    CONFIGEN: A tool for managing configuration options

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    This paper introduces CONFIGEN, a tool that helps modularizing software. CONFIGEN allows the developer to select a set of elementary components for his software through an interactive interface. Configuration files for use by C/assembly code and Makefiles are then automatically generated, and we successfully used it as a helper tool for complex system software refactoring. CONFIGEN is based on propositional logic, and its implementation faces hard theoretical problems.Comment: In Proceedings LoCoCo 2010, arXiv:1007.083

    Exploiting Template Metaprogramming to customize an object-oriented operating system

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    Nowadays, the growing complexity of embedded systems demands for configurability, variability and reuse. Conditional compilation and object-orientation are two of the most applied approaches in the management of system variability. While the former increases the code management complexity, the latter leverages the needed modularity and adaptability to simplify the development of reusable and customizable software at the expense of performance and memory penalty. This paper shows how C++ TMP (Template Metaprogramming) can be applied to manage the variability of an object-oriented operating system and at the same time get ride out of the performance and memory footprint overhead. In doing so, it will be statically generated only the desired functionalities, thus ensuring that code is optimized and adjusted to application requirements and hardware resources.Fundação para a Ciência e a Tecnologia (FCT
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