Biometric identification systems are depicted as foolproof crime-fighting tools in Hollywood but in reality they are far from perfect, a report said.

The report from National Research Council said identification systems that rely on fingerprints, palm prints or voice recognition or the like are "inherently fallible" and urged government agencies to make sure that a system they invest in works as advertised.

Governments and companies increasingly are looking to biometric systems as a better way to track terrorists at borders, control access to buildings or provide a convenient way to access bank accounts.

Finger-imaging sensors are now appearing on consumer products including laptops, hand-held devices and cell phones.

Bob Blakley of Burton Group Identity and Privacy Strategies in Texas, who worked on the report done by a panel for the National Academy of Sciences, said governments and companies need to be sure the technology is up to the task.

"We shouldn't just choose biometrics because it is sexy and looks good in science fiction movies. We should do it because it is the most effective solution to the problem," Blakley said in a telephone interview.

He said many large-scale biometric systems work well, citing the FBI fingerprint database, or the fingerprint system used recently in Nigeria to prevent voter fraud.

"However, those systems have been carefully designed and expertly reviewed. It's really easy to take a good biometrics scanner and use it to build a bad system," Blakley said.

Besides fingerprinting, biometric security systems can use voice recognition, face recognition, hand geometry systems that measure the lengths of fingers and size of palms, a form of finger recognition that looks at capillaries in the hand, and even gait recognition -- recognizing a person's way of walking.

One big drawback of systems that rely on physical characteristics is that people change over time. Faces sag with age. Stress or disease can change a person's voice or cause them to lose or gain weight.

Sensors may develop glitches, data can become degraded, and security of information can be breached.

Blakley said retail stores that use fingerprint systems to access a person's bank account could expose people to fraud and identity theft.

He said with a bank card and a personal identification number, people can simply replace the card and choose a new PIN if it is stolen. But if a fingerprint ID is stolen, you can't replace your finger, he said. – Reuters