114,895 research outputs found
Model checking multi-agent systems
A multi-agent system (MAS) is usually understood as a system composed of interacting
autonomous agents. In this sense, MAS have been employed successfully as a modelling
paradigm in a number of scenarios, especially in Computer Science. However, the process
of modelling complex and heterogeneous systems is intrinsically prone to errors: for this
reason, computer scientists are typically concerned with the issue of verifying that a system
actually behaves as it is supposed to, especially when a system is complex.
Techniques have been developed to perform this task: testing is the most common technique,
but in many circumstances a formal proof of correctness is needed. Techniques
for formal verification include theorem proving and model checking. Model checking
techniques, in particular, have been successfully employed in the formal verification of
distributed systems, including hardware components, communication protocols, security
protocols.
In contrast to traditional distributed systems, formal verification techniques for MAS are
still in their infancy, due to the more complex nature of agents, their autonomy, and
the richer language used in the specification of properties. This thesis aims at making
a contribution in the formal verification of properties of MAS via model checking. In
particular, the following points are addressed:
ā¢ Theoretical results about model checking methodologies for MAS, obtained by
extending traditional methodologies based on Ordered Binary Decision Diagrams (OBDDS) for temporal logics to multi-modal logics for time, knowledge, correct behaviour, and strategies of agents. Complexity results for model checking these logics
(and their symbolic representations).
ā¢ Development of a software tool (MCMAS) that permits the specification and verification
of MAS described in the formalism of interpreted systems.
ā¢ Examples of application of MCMAS to various MAS scenarios (communication, anonymity, games, hardware diagnosability), including experimental results, and comparison with other tools available
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A Static Verification Framework for Secure Peer-to-Peer Applications
In this paper we present a static verification framework to support the design and verification of secure peer-to-peer applications. The framework supports the specification, modeling, and analysis of security aspects together with the general characteristics of the system, during early stages of the development life-cycle. The approach avoids security issues to be taken into consideration as a separate layer that is added to the system as an afterthought by the use of security protocols. The main functionality supported by the framework are concerned with the modeling of the system together with its security aspects by using an extension of UML, modeling of abuse cases to represent scenarios of attackers and assist with the identification of properties to be verified, specification of properties to be verified in a graphical template language, verification of the models against the properties, and visualization of the results of the verification process
An algebraic basis for specifying and enforcing access control in security systems
Security services in a multi-user environment are often based on access control mechanisms. Static aspects of an access control policy can be formalised using abstract algebraic models. We integrate these static aspects into a dynamic framework considering requesting access to resources as a process aiming at the prevention of access control violations when a program is executed. We use another algebraic technique, monads, as a meta-language to integrate access control operations into a functional
programming language. The integration of monads and concepts from a denotational model for process algebras provides a framework for programming of access control in security systems
XRound : A reversible template language and its application in model-based security analysis
Successful analysis of the models used in Model-Driven Development requires the ability to synthesise the results of analysis and automatically integrate these results with the models themselves. This paper presents a reversible template language called XRound which supports round-trip transformations between models and the logic used to encode system properties. A template processor that supports the language is described, and the use of the template language is illustrated by its application in an analysis workbench, designed to support analysis of security properties of UML and MOF-based models. As a result of using reversible templates, it is possible to seamlessly and automatically integrate the results of a security analysis with a model. (C) 2008 Elsevier B.V. All rights reserved
Applying Formal Methods to Networking: Theory, Techniques and Applications
Despite its great importance, modern network infrastructure is remarkable for
the lack of rigor in its engineering. The Internet which began as a research
experiment was never designed to handle the users and applications it hosts
today. The lack of formalization of the Internet architecture meant limited
abstractions and modularity, especially for the control and management planes,
thus requiring for every new need a new protocol built from scratch. This led
to an unwieldy ossified Internet architecture resistant to any attempts at
formal verification, and an Internet culture where expediency and pragmatism
are favored over formal correctness. Fortunately, recent work in the space of
clean slate Internet design---especially, the software defined networking (SDN)
paradigm---offers the Internet community another chance to develop the right
kind of architecture and abstractions. This has also led to a great resurgence
in interest of applying formal methods to specification, verification, and
synthesis of networking protocols and applications. In this paper, we present a
self-contained tutorial of the formidable amount of work that has been done in
formal methods, and present a survey of its applications to networking.Comment: 30 pages, submitted to IEEE Communications Surveys and Tutorial
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