Applying Policy Based Access Control and XML Digital Signatures for Security in Pervasive Computing Environments

Security and access control are one of the major issues within pervasive computing environments such as Task Computing. There is a need of unobtrusive and flexible access control and access to services has to be restricted based on certain policies imposed by the organization (Fujitsu in this case). The dynamic nature of pervasive computing environments also requires the updating of policies on the fly.

REI developed at University of Maryland Baltimore County is an expressive and extensible language for describing different kinds of policies in a wide range of application domains such as security policies / privacy policies. The REI policy engine reasons over REI policies and domain knowledge to provide answers about current permissions and obligations of an entity dynamically. REI allows the dynamic change of policies on the fly through its provision of speech acts such as delegation.

Using Task Computing as a platform we have shown that REI can be used in highly pervasive and ubiquitous environments to provide access control decisions. These decisions are based on facts provided by the client, resource/service policies, shared policies and ontologies depicting the domain knowledge of the organization. In addition XML Digital Signatures are used to provide authentication and data integrity.