1,721,027 research outputs found
Self-Adaptive Systems for Information Survivability: PMOP and AWDRAT
Full text linkInformation systems form the backbones of the critical infrastructures of modern societies. Unfortunately, these systems are highly vulnerable to attacks that can result in enormous damage. Furthermore, traditional approaches to information security have not provided all the protections necessary to defeat and recover from a concerted attack; in particular, they are largely irrelevant to the problem of defending against attacks launched by insiders.This paper describes two related systems PMOP and AWDRAT that were developed during the DARPA Self Regenerative Systems program. PMOP defends against insider attacks while AWDRAT is intended to detect compromises to software systems. Both rely on self-monitoring, diagnosis and self-adaptation. We describe both systems and show the results of experiments with each
New solutions for cybersecurity
Full text linkHoward Shrobe, David L. Shrier and Alex Pentland (eds.)New Solutions for Cybersecurity, Cambridge MA, MIT Press, 2018, pp.49
New solutions for cybersecurity
Full text linkHoward Shrobe, David L. Shrier and Alex Pentland (eds.)New Solutions for Cybersecurity, Cambridge MA, MIT Press, 2018, pp.49
Sound and Complete Runtime Security Monitor for Application Software
Full text linkWe present a run-time security monitor that detects both known and unknown cyber attacks by checking that the run-time behavior of the application is consistent with the expected behavior modeled by an application specification. This is crucial because, even if the implementation is consistent with its specification, the application may still be vulnerable due to flaws in the supporting infrastructure. This run-time security monitor is sound and complete, eliminating false alarms, as well as efficient, so that it does not limit run-time application performance and so that it supports real-time systems. Importantly, this monitor is readily applicable to both legacy and new system platforms.The security monitor takes as input the application specification and the application implementation, which may be expressed in different languages. The security monitor detects attacks by systematically comparing the application execution and specification behaviors at run-time, even though they operate at two different levels of abstraction. We define the denotational semantics of the specification language and prove that the monitor is sound and complete, i.e. if the application is consistent with its specification, the security monitor will produce no false alarms (soundness) and that it will detect any deviation of the application from the behavior sanctioned by the specification language (completeness). Importantly, the application specification language enables the description of known or potential attack plans, enabling not only attack detection but attack characterization as well
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Distributed Area Search with a Team of Robots
Full text linkMEng thesisThe main goal of this thesis is to demonstrate the applicability of the distributed systems paradigm to robotic systems. This goal is accomplished by presenting two solutions to the Distributed Area Search problem: organizing a team of robots to collaborate in the task of searching through an area. The first solution is designed for unreliable robots equipped with a reliable GPS-style localization system. This solution demonstrates the efficiency and fault-tolerance of this type of distributed robotic systems, as well as their applicability to the real world. We present a theoretically near-optimal algorithm for solving Distributed Area Search under this setting, and we also present an implementation of our algorithm on an actual system, consisting of twelve robots. The second solution is designed for a completely autonomous system, without the aid of any centralized subsystem. It demonstrates how a distributed robotic system can solve a problem that is practically unsolvable for a single-robot system
TIARA: Trust Management, Intrusion-tolerance, Accountability, and Reconstitution Architecture
Full text linkThe last 20 years have led to unprecedented improvements in chipdensity and system performance fueled mainly by Moore's Law. Duringthe same time, system and application software have bloated, leadingto unmanageable complexity, vulnerability to attack, rigidity and lackof robustness and accountability. These problems arise from the factthat all key elements of the computational environment, from hardwarethrough system software and middleware to application code regard theworld as consisting of unconstrained ``raw seething bits''. No elementof the entire stack is responsible for enforcing over-archingconventions of memory structuring or access control. Outsiders mayeasily penetrate the system by exploiting vulnerabilities (e.g. bufferoverflows) arising from this lack of basic constraints. Attacks arenot easily contained, whether they originate from the clever outsiderwho penetrates the defenses or from the insider who exploits existingprivileges. Finally, because there are no facilities for tracing theprovenance of data, even when an attack is detected, it is difficultif not impossible to tell which data are traceable to the attack andwhat data may still be trusted. We have abundant computational resources allowing us to fix thesecritical problems using a combination of hardware, system software,and programming language technology: In this report, we describe theTIARAproject, which is using these resources to design a newcomputer system thatis less vulnerable, more tolerant of intrusions, capable of recoveryfrom attacks, and accountable for their actions. TIARA provides thesecapabilities without significant impact on overall system performance. Itachieves these goals through the judicious use of a modest amountof extra, but reasonably generable purpose, hardware that is dedicatedto tracking the provenance of data at a very fine grained level, toenforcing access control policies, and to constructing a coherentobject-oriented model of memory. This hardware runs in parallel withthe main data-paths of the system and operates on a set of extra bitstagging each word with data-type, bounds, access control andprovenance information. Operations that violate the intendedinvariants are trapped, while normal results are tagged withinformation derived from the tags of the input operands.This hardware level provides fine-grained support for a series ofsoftware layers that enable a variety of comprehensive access controlpolicies, self-adaptive computing, and fine-grained recoveryprocessing. The first of these software layers establishes aconsistent object-oriented level of computing while higher layersestablish wrappers that may not be bypassed, access controls, dataprovenance tracking. At the highest level we create the ``planlevel'' of computing in which code is executed in parallel with anabstract model (or executable specification) of the system that checkswhether the code behaves as intended
Continuous Space-Time Semantics Allow Adaptive Program Execution
Full text linkA spatial computer is a collection of devices filling spacewhose ability to interact is strongly dependent on theirproximity. Previously, we have showed that programmingsuch a computer as a continuous space can allow self-scalingacross computers with different device distributionsand can increase robustness against device failure. Wehave extended these ideas to time, allowing self-scalingacross computers with different communication and executionrates. We have used a network of 24 Mica2 Motes todemonstrate that a program exploiting these ideas showsminimal difference in behavior as the time between programsteps ranges from 100 ms to 300 ms and on a configurationwith mixed rates
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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