GEM: a Distributed Goal Evaluation Algorithm for Trust Management

Trust management is an approach to access control in distributed systems where access decisions are based on policy statements issued by multiple principals and stored in a distributed manner. In trust management, the policy statements of a principal can refer to other principals' statements; thus, the process of evaluating an access request (i.e., a goal) consists of finding a "chain" of policy statements that allows the access to the requested resource. Most existing goal evaluation algorithms for trust management either rely on a centralized evaluation strategy, which consists of collecting all the relevant policy statements in a single location (and therefore they do not guarantee the confidentiality of intensional policies), or do not detect the termination of the computation (i.e., when all the answers of a goal are computed). In this paper we present GEM, a distributed goal evaluation algorithm for trust management systems that relies on function-free logic programming for the specification of policy statements. GEM detects termination in a completely distributed way without disclosing intensional policies, thereby preserving their confidentiality. We demonstrate that the algorithm terminates and is sound and complete with respect to the standard semantics for logic programs.Comment: To appear in Theory and Practice of Logic Programming (TPLP

SETTING UP AN INDUSTRIAL CONTROL SYSTEMS LABORATORY

With the evolution of Industrial Control Systems, many solutions from vendors are offered for industries. But sadly, most of those solutions are close-sourced, delivering lack of support for third parties who aim to develop Industrial Control Systems further. A start-up company named SecurityMatters needs an industrial instrument to simulate industrial environment to have a better idea how a particular protocol works. The application made in this project was developed using Java programming language to have compatibilities across platforms. An Object-Oriented-Programming and Model-View-Controller pattern are used as well to ensure maintainability. This application can be used to demonstrate capabilities of Modbus protocol and test industrial devices for vulnerabilities

Transience of conditioned walks on the plane: Encounters and speed of escape

We consider the two-dimensional simple random walk conditioned on never hitting the origin, which is, formally speaking, the Doob’s h-transform of the simple random walk with respect to the potential kernel. We then study the behavior of the future minimum distance of the walk to the origin, and also prove that two independent copies of the conditioned walk, although both transient, will nevertheless meet infinitely many times a.s.Fil: Popov, Serguei. Universidad de Porto; Portugal. Universidade Estadual de Campinas; BrasilFil: Trivellato Rolla, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigaciones Matemáticas "Luis A. Santaló". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Matemáticas "Luis A. Santaló"; ArgentinaFil: Ungaretti, Daniel. Universidade Estadual de Campinas; Brasi

A flexible architecture for privacy-aware trust management

In service-oriented systems a constellation of services cooperate, sharing potentially sensitive information and responsibilities. Cooperation is only possible if the different participants trust each other. As trust may depend on many different factors, in a flexible framework for Trust Management (TM) trust must be computed by combining different types of information. In this paper we describe the TAS3 TM framework which integrates independent TM systems into a single trust decision point. The TM framework supports intricate combinations whilst still remaining easily extensible. It also provides a unified trust evaluation interface to the (authorization framework of the) services. We demonstrate the flexibility of the approach by integrating three distinct TM paradigms: reputation-based TM, credential-based TM, and Key Performance Indicator TM. Finally, we discuss privacy concerns in TM systems and the directions to be taken for the definition of a privacy-friendly TM architecture.\u

Setting Up an Industrial Control Systems Laboratory

With the evolution of Industrial Control Systems, many solutions from vendors are offered for industries. But sadly, most of those solutions are close-sourced, delivering lack of support for third parties who aim to develop Industrial Control Systems further. A start-up company named SecurityMatters needs an industrial instrument to simulate industrial environment to have a better idea how a particular protocol works. The application made in this project was developed using Java programming language to have compatibilities across platforms. An Object-Oriented-Programming and Model-View-Controller pattern are used as well to ensure maintainability. This application can be used to demonstrate capabilities of Modbus protocol and test industrial devices for vulnerabilities

GEM: a Distributed Goal Evaluation Algorithm for Trust Management

ABSTRACT Trust Management (TM) is an approach to distributed access control where access decisions are based on policy statements issued by multiple principals and stored in a distributed manner. Most of the existing goal evaluation algorithms for TM either rely on a centralized evaluation strategy, which consists of collecting all the relevant policy statements in a single location (and therefore they do not guarantee the confidentiality of intensional policies), or do not detect the termination of the computation (i.e., when all the answers of a goal are computed). In this paper we present GEM, a distributed goal evaluation algorithm for TM systems. GEM detects termination in a completely distributed way without the need of disclosing intensional policies, thereby preserving their confidentiality. We demonstrate that the algorithm terminates and is sound and complete w.r.t. the standard semantics for logic programs

WebQuest per a l'estudi lingüístic de la veu i la comunicació

zip comprimit, Pàgina inicial: 216/index.htmlLes WebQuest són entorns de materials docents per a l'aprenentatge pràctic i cooperatiu. Aquesta WebQuest planteja l'estudi i l'aplicació de conceptes de la Lingüística a situacions concretes de comunicació. En aquestes situacions es considera les següents qüestions: Com comunica un bebè?; i un infant d'un parell d'anys? Com es comunica una persona que ha patit una operació a la laringe o la llengua? Aquest material està vinculat a un altre document, 'Adquisició del llenguatge, parla infantil i anàlisi lingüística'

Informe sobre el I Congresso Ibero-americano de Gestão do Conhecimento e Inteligência Competitiva (Curitiba, el Brasil, 29, 30 i 31 de agosto de 2006) [spa]

Podeu consultar la versió en català a http://hdl.handle.net/2445/8956Durante los días 29, 30 y 31 del pasado mes de agosto de 2006, se celebró en la ciudad de Curitiba (Paraná, Brasil) el I Congresso Ibero-americano de Gestão do Conhecimento e Inteligência Competitiva. Este congreso estaba organizado por la Sociedade Brasileira de Gestão do Conhecimento (SBGC) y la Associasão Brasileira dos Analistas do Inteligência Competitiva (ABRAIC). El evento, que superó el millar de asistentes, intentaba congregar una parte importante de los académicos y profesionales de Latinoamérica, Portugal y España dedicados a los temas de la Gestión del Conocimiento y de la Inteligencia Competitiva. En este sentido, además de aportar un programa y una temática común autónoma, estaba también diseñado para acoger y aglutinar de forma simultánea y paralela una serie de acontecimientos académicos y profesionales ya consolidados anteriormente en este espacio geográfico. Estos acontecimiento acogidos fueron el KM Brasil 2006 (congreso sobre Gestión del Conocimiento organizado anualmente por la Sociedade Brasileira de Gestão do Conhecimento - SBGC), el 7º Workshop brasileiro de Inteligência Competitiva e Gestão do Conhecimento, el III Encontro Nacional de ABRAIC (encuentro anual organizado por la Associasão Brasileira dos Analistas do Inteligência Competitiva - ABRAIC) y el II Prêmio de Inovação em Inteligência Competitiva (premio dirigido a los profesionales que desarrollan su praxis en el campo de la inteligencia competitiva y organizado también por la ABRAIC)