Personal Firewalls and Intrusion Detection Systems

In this paper we explore how secure coprocessors can be used to secure client devices, especially mobile clients such as notebook computers. The goal is to protect data on the mobile client in case of theft, and to adapt the client's protection to the working environment --such as the Intranet or Internet-without relying completely on the integrity of the client. We show how physically secure coprocessors can introduce a security lifecycle into commercial off the shelf (COTS) clients by booting the client into a secure starting state, supervising the client's configuration and operation, and inspecting any network traffic that is sent or received by the client.