What if it were possible to implement a secure system that could foil potential terrorists at their very earliest stage of planning?

Security officials at the Los Angeles International Airport (LAX) are experimenting with what they hope might be a solution. Developed by Viterbi School of Engineering computer scientists at the University of Southern California in Los Angeles (USC), Calif., ARMOR aims to enhance security measures by making them totally unpredictable. The software works by taking all the available resources of an entire security system to create a completely randomized schedule for officials to follow. The system has been designed not only to provide as much cover as a conventional schedule but it will also make it impossible for any observer to find patterns or regularities in LAX security routines that could be exploited as part of his or her plan.

Created by a team of artificial intelligence experts led by Milind Tambe, a USC professor, the software is based on game theory and will allow officials to improve security significantly by using existing resources without incurring any additional costs.

“The idea is to use game theory to randomize how patrols are done, checkpoints are placed, etcetera, making the ‘routine’ actions of LAX police unpredictable,” said Tambe. “ARMOR casts the problem of such patrols, checkpoints as a game and creates a randomized strategy as a solution.”

The routine enemy

Security planners face the extremely challenging task of having to design security measures that will provide total coverage with the existing resources at reasonable costs. While “routine” is generally considered to be the enemy of good security, it becomes almost impossible to avoid given the magnitude of the job at hand, the difficulty of finding reliable people and the pressure to keep costs low. Officials find themselves in the unenviable position of inevitably having to commit to a routine that may contain vulnerabilities potential terrorists can exploit simply by patient observation.

In a keynote address to the US-Europe Aviation Security Policy Conference delivered earlier this year, Kip Hawley, assistant secretary of homeland security for the Transportation Security Administration (TSA), said, “For terrorists, it is easy to plot against a system so predictable they know exactly what to expect each time they approach it. Unpredictability is a crucial tool in thwarting terrorists’ attack plans. If an element of unpredictability is introduced—such as changing or adding inspection routines on a variable basis or using canine teams at different places each day—this randomness increases the complexity for would-be terrorists. It is one of our best tools to defeat them.” (The entire speech can be read here.)