Network Meta-Reasoning for Information Assurance in Mobile Agent Systems

This paper develops a practical means of measuring information assurance for mobile agent systems operating on wireless, ad hoc networks based on meta-reasoning [Dix et ai, 2000; Xuan et al, 2001] to improve the security of communication. Figure 1 shows an agent system and its two distinct layers of communication: host-to-host and agent-toagent. Given the plethora of new techniques for identifying network intruders, we study the compromised host problem: determining the appropriate response to an identified intruder. In the context of a mobile, multi-agent system operating on an ad hoc network [Forman & Zahorjan, 1994], it is not merely a simple matter of removing the compromised hosts and its agents. While keeping the compromised host can result in information disclosure, removal of the host can degrade or even sever the network. Wc develop a state description for an agent system and introduce a measure of* information assurance for the system in terms of the integrity of the messages delivered to the agents in a given network state. Agents have three responses to a compromised host: ignore the compromised host; reroute around the compromised host using network route redundancies; or remove the compromised host, by having the agents instruct their hosts to eliminate it from the network. These responses are shown in Figure 2.