Security in Agent Systems1.7 The Mists of Time"Here be dragons" As a system becomes more complex and more interconnected, it is more likely to exhibit large-scale behaviors that we would not predict from knowledge of the individual elements. The worldwide computer-virus problem, for instance, turns out to depend more on various characteristics of the computing infrastructure than on the bits and bytes of any particular virus [10]. Telephone networks have been brought down by obscure bugs in computerized switches, where the chances of any one switch failing was small, but once one had failed, the effect spread to its neighbors in unanticipated ways [11]. What sorts of emergent failures and security weaknesses might we expect to see in highly-connected agent systems? [12], for instance, shows that increasing the intelligence of the elements of a system does not necessarily improve the behavior of the system as a whole; seemingly-intelligent strategies can interact perversely. As agents begin to exchange, process, retransmit, and otherwise shuffle information, we can expect to see more sophisticated versions of the message-routing loops that occur in current networks. Relatively simple message tracking solutions suffice to prevent simple loops, but loops that involve more complex transformations and combinations of data are much harder to prevent [13]. Traffic floods caused by such loops can be accidental annoyances, or intentional attacks. Viruses of various kinds may also be a problem in some kinds of agent systems. For instance, any system that allows one agent to modify or replace another may be vulnerable to a spreading attack, where a piece of malicious code modifies other agents to include a copy of itself. Eventually, the code might be widely distributed around the system, and able to do various sorts of damage. A bit farther afield, one can imagine an information virus, that spreads between knowledge-based intelligent agents that exchange production rules. An infected agent would contain a set of rules that would make the agent more likely to send those rules to other agents. See [14] for further speculation on more or less exotic phenomena that may grow in future networks.[ Top of Page | Previous Page | Next Page | Table of Contents ] |