Intensive screening of passengers makes air travel vulnerable to attacks

Washington, Feb 1 (ANI): Extensive screening of all passengers actually makes the system less secure by overtaxing security resources, according to a new study.

University of Illinois computer science and mathematics professor Sheldon H. Jacobson, in collaboration with Adrian J. Lee at the Central Illinois Technology and Education Research Institute, explored the benefit of matching passenger risk with security assets.

"A natural tendency, when limited information is available about from where the next threat will come, is to overestimate the overall risk in the system," Jacobson said.

"This actually makes the system less secure by over-allocating security resources to those in the system that are low on the risk scale relative to others in the system."

When overestimating the population risk, a larger proportion of high-risk passengers are designated for too little screening while a larger proportion of low-risk passengers are subjected to too much screening.

With security resources devoted to the many low-risk passengers, those resources are less able to identify or address high-risk passengers. Nevertheless, current policies favour broad screening.

"One hundred percent checked baggage screening and full-body scanning of all passengers is the antithesis of a risk-based system," Jacobson said.

"It treats all passengers and their baggage as high-risk threats. The cost of such a system is prohibitive, and it makes the air system more vulnerable to successful attacks by sub-optimally allocating security assets."

In an effort to address this problem, the Transportation Security Administration (TSA) introduced a pre-screening program in 2011, available to select passengers on a trial basis.

In the new study, Jacobson and Lee developed three algorithms dealing with risk uncertainty in the passenger population.

Then, they ran simulations to demonstrate how their algorithms, applied to a risk-based screening method, could estimate risk in the overall passenger population - instead of focusing on each individual passenger - and how errors in this estimation procedure can be mitigated to reduce the risk to the overall system.

They found that risk-based screening, such as the TSA's new Pre-Check program, increases the overall expected security. Rating a passenger's risk relative to the entire flying population allows more resources to be devoted to passengers with a high risk relative to the passenger population.

"The TSA's move toward a risk-based system is designed to more accurately match security assets with threats to the air system," Jacobson said.

"The ideal situation is to create a system that screens passengers commensurate with their risk. Since we know that very few people are a threat to the system, relative risk rather than absolute risk provides valuable information," Jacobson added.

The study has been published in the journal Transportation Science. (ANI)