Date of Award

Fall 2009

Degree Type

Thesis - Restricted

Degree Name

Master of Science (MS)


Mathematics, Statistics and Computer Science

First Advisor

Ahamed, Sheikh I.

Second Advisor

Harris, Douglas

Third Advisor

Madiraju, Praveen


In recent years, there has been a tremendous growth in sharing of resources, services and content among different types of devices in a pervasive environment. This growth necessitates an efficient way of sharing the resources to ensure no devices can misuse others' resources. However, this type of activity in a pervasive environment always entails security breaches and privacy violations. In the literature, trust models have been used to solve this kind of problem. A trust value in these models is used to quantify security parameters, access level to a resource, amount of sharing etc. However, most of these trust models start with a constant value for any device regardless of the types of interactions. This assumption of constant value significantly undermines the effectiveness of a trust model. In this thesis, we found initial trust level is instead dynamic based on the context of a sharing activity. Context is defined as a set of conditions on which an activity changes. Initial level of trust also plays an important role in the transactions of E-commerce. It is found that most of the customers hesitate to make a transaction with the unknown websites due to the lack of initial trust. Therefore, we need a generic solution, which can dynamically predict the initial level of trust based on a context in various types of computing environments. In this thesis, we have addressed various problems of modeling a context and proposed approaches to solve those problems. We then proposed a model to predict the initial level of trust for a specific context. We have used several mathematical methods in our approaches and implemented prototypes to evaluate our claims.