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Assurance management framework for access control systems

Description

Access control is one of the most fundamental security mechanisms used in the design and management of modern information systems. However, there still exists an open question on how formal access control models can be automatically analyzed and fully realized

Access control is one of the most fundamental security mechanisms used in the design and management of modern information systems. However, there still exists an open question on how formal access control models can be automatically analyzed and fully realized in secure system development. Furthermore, specifying and managing access control policies are often error-prone due to the lack of effective analysis mechanisms and tools. In this dissertation, I present an Assurance Management Framework (AMF) that is designed to cope with various assurance management requirements from both access control system development and policy-based computing. On one hand, the AMF framework facilitates comprehensive analysis and thorough realization of formal access control models in secure system development. I demonstrate how this method can be applied to build role-based access control systems by adopting the NIST/ANSI RBAC standard as an underlying security model. On the other hand, the AMF framework ensures the correctness of access control policies in policy-based computing through automated reasoning techniques and anomaly management mechanisms. A systematic method is presented to formulate XACML in Answer Set Programming (ASP) that allows users to leverage off-the-shelf ASP solvers for a variety of analysis services. In addition, I introduce a novel anomaly management mechanism, along with a grid-based visualization approach, which enables systematic and effective detection and resolution of policy anomalies. I further evaluate the AMF framework through modeling and analyzing multiparty access control in Online Social Networks (OSNs). A MultiParty Access Control (MPAC) model is formulated to capture the essence of multiparty authorization requirements in OSNs. In particular, I show how AMF can be applied to OSNs for identifying and resolving privacy conflicts, and representing and reasoning about MPAC model and policy. To demonstrate the feasibility of the proposed methodology, a suite of proof-of-concept prototype systems is implemented as well.

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Created

Date Created
2012

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Establishing distributed social network trust model in MobiCloud system

Description

This thesis proposed a novel approach to establish the trust model in a social network scenario based on users' emails. Email is one of the most important social connections nowadays. By analyzing email exchange activities among users, a social network

This thesis proposed a novel approach to establish the trust model in a social network scenario based on users' emails. Email is one of the most important social connections nowadays. By analyzing email exchange activities among users, a social network trust model can be established to judge the trust rate between each two users. The whole trust checking process is divided into two steps: local checking and remote checking. Local checking directly contacts the email server to calculate the trust rate based on user's own email communication history. Remote checking is a distributed computing process to get help from user's social network friends and built the trust rate together. The email-based trust model is built upon a cloud computing framework called MobiCloud. Inside MobiCloud, each user occupies a virtual machine which can directly communicate with others. Based on this feature, the distributed trust model is implemented as a combination of local analysis and remote analysis in the cloud. Experiment results show that the trust evaluation model can give accurate trust rate even in a small scale social network which does not have lots of social connections. With this trust model, the security in both social network services and email communication could be improved.

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Created

Date Created
2011

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Topic chains for determining risk of unauthorized information transfer

Description

Corporations invest considerable resources to create, preserve and analyze

their data; yet while organizations are interested in protecting against

unauthorized data transfer, there lacks a comprehensive metric to discriminate

what data are at risk of leaking.

This thesis motivates the need for

Corporations invest considerable resources to create, preserve and analyze

their data; yet while organizations are interested in protecting against

unauthorized data transfer, there lacks a comprehensive metric to discriminate

what data are at risk of leaking.

This thesis motivates the need for a quantitative leakage risk metric, and

provides a risk assessment system, called Whispers, for computing it. Using

unsupervised machine learning techniques, Whispers uncovers themes in an

organization's document corpus, including previously unknown or unclassified

data. Then, by correlating the document with its authors, Whispers can

identify which data are easier to contain, and conversely which are at risk.

Using the Enron email database, Whispers constructs a social network segmented

by topic themes. This graph uncovers communication channels within the

organization. Using this social network, Whispers determines the risk of each

topic by measuring the rate at which simulated leaks are not detected. For the

Enron set, Whispers identified 18 separate topic themes between January 1999

and December 2000. The highest risk data emanated from the legal department

with a leakage risk as high as 60%.

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Agent

Created

Date Created
2014