A Trust Model for Pervasive Computing Environments

With the growth of mobile and sensor devices, embedded systems, and communication technologies, we are moving towards an era of pervasive computing. Pervasive computing applications typically involve interactions between a large number of entities that span different organizations. Uncontrolled disclosure of information or unconstrained interaction among entities may have extremely grave consequences. Traditional security policies and mechanisms are inadequate for pervasive computing applications. Unlike traditional applications, pervasive computing applications have no definite security perimeters and are dynamic in nature. Pervasive computing applications may need to interact with entities that are not known a priori and therefore cannot be trusted. The traditional binary notion of trust where known entities are completely trusted and unknown entities are distrusted are not suitable for such applications. To fill this gap, we develop a trust model useful for pervasive computing applications and develop strategies for establishing trust between entities. The model must accommodate the notion of different degrees of trust, identify how to determine the trust value, and define how trust changes over time

I. Introduction

With the growth of mobile and sensor devices, embedded systems, and communication technologies, we are moving towards an era of pervasive computing. Pervasive computing is expected to create a revolution by providing services and functionalities that use the knowledge of surrounding physical places. The very knowledge that enables an application to provide better services and functionalities may however be misused causing security and privacy breaches. The problem is serious because pervasive computing applications typically involve interactions between a large number of entities that span different organizations. Uncontrolled disclosure of information or unconstrained interaction among entities may have extremely grave consequences. We need to understand what resources an entity has access to, which entities it should interact with, what information can be released to an entity, how to protect the information used or produced by an entity, which entities can be trusted and to what extent, and how these trust relationships change over time.