Trusted Mobile Computing

Mobility leads to unplanned interactions between computer systems as people use devices to access services in varied environments. Before two systems agree to interact, they must trust that each will satisfy the security and privacy requirements of the other. In this paper we introduce trust overlays, a systematic approach to building such trust. Our solution exploits the increasing availability of trusted computing hardware on commodity systems, including portable computers. We report that key pieces of this solution are coming into place, for example systems that provide distributed mandatory access control. We also point out that difficult challenges remain, for example how to set compatible security policies across administrative domains.