Managing Access Control in the Presence of Physical and Logical Mobility

The emerging mobile computing environment draws new attention to the need for coordination among networked components. The very nature of this environment requires parties to interact even when they have never met before, and subsequent encounters are totally unpredictable. Because mobile networks are often decoupled from any fixed network infrastructure, reliance on centralized servers to authenticate agents and to establish data access policies is impractical. Access control is a key component of security in such systems, and application agents must be able to directly manipulate and examine policies because they need full and flexible control over their data. Starting from this premise, we examine the essential features of general access control policies designed to respond to the specific needs of agent coordination in the presence of logical and physical mobility. A novel construct to support such policies is proposed and evaluated with respect to its impact on mobile applications. We also show some example uses of this access control construct.