Eyeballs, a severed hand, or fingers carried in ziplock bags. Back alley eye replacement surgery. These are scenarios used in recent blockbuster movies like Steven Spielberg's "Minority Report" and "Tomorrow Never Dies" to illustrate how unsavory characters in high-tech worlds beat sophisticated security and identification systems.

Sound fantastic? Maybe not. Biometrics is the science of using biological properties, such as fingerprints, an iris scan, or voice recognition, to identify individuals. And in a world of growing terrorism concerns and increasing security measures, the field of biometrics is rapidly expanding.

"Biometric systems automatically measure the unique physiological or behavioral ‘signature' of an individual, from which a decision can be made to either authenticate or determine that individual's identity," explained Stephanie C. Schuckers, an associate professor of electrical and computer engineering at Clarkson University. "Today, biometric systems are popping up everywhere – in places like hospitals, banks, even college residence halls – to authorize or deny access to medical files, financial accounts, or restricted or private areas."

"And as with any identification or security system," Schuckers adds, "biometric devices are prone to ‘spoofing' or attacks designed to defeat them."