Security is an essential part of our lives, and technology can play a great role in increasing the level of security. In today's tech-driven world, a new lab is working on special shoe insoles designed to monitor access to high-security areas such as military bases or nuclear power plants.

The concept for these insoles builds on extensive research that shows each individual has unique feet and ways of walking. The biometric soles include several sensors designed to check the pressure of feet, monitor gait (i.e. the way of walking), and use a microcomputer to compare the patterns with those registered in a master file for that person. If the patterns match, no harm done. If not, a wireless alarm message can be triggered. "It's part of a shoe that you don't have to think about," said Marios Savvides, head of the new Pedo-Biometrics Lab at Carnegie Mellon University in Pittsburgh, according to the Associated Press (AP).

The lab received $1.5 million in startup funding, and is in partnership with Canadian company Autonomous ID, that is relocating in several cities in the United States. Autonomous ID president Todd Gray said he saw the potential for this concept when his daughter was in a maternity ward decorated with representations of various baby feet.

The Canadian company has been flirting with the concept and working on prototypes since 2009, aiming to create a relatively low cost ID system. According to Gray, the company has already run tests on sample biometric soles, which are no thicker than common foot pads. The tests reportedly yielded an accuracy rate of more than 99 percent.

Gray said Carnegie Mellon will broaden the tests to include "a full spectrum of society: big, tall, thin, heavy, athletic, multicultural, on a diet, twins and so on." He declined, however, to speculate on how much the system would cost, or when it might hit the market, but said each worker at a site would have his or her own pair of biometric soles. "Within the third step, it knows it's you, and it goes back to sleep," explained Gray. "If I put on yours, it would know almost instantly that I'm not you."

Scientists have known for centuries that each person has a unique way of walking, and the U.S. Department of Defense, as well as the Chinese government, have been pouring millions into funding gait research. The Institute of Intelligent Machines is also doing extensive research into gait biometrics, and there are even reports of systems where a floor can monitor footsteps without people's knowledge.

"I must admit I find this news very exciting," said John DiMaggio, an Oregon podiatrist who has assisted law enforcement in forensic investigations. DiMaggio, who is not connected with the CMU lab, said it is too early to fully assess the CMU research plan, but using fee as a biometric identification source does make sense.

Researchers are also aware that gait can vary with injuries, fatigue, and other factors, but Savvides said the bio-soles would be able to detect such things as well. In addition, the soles might also have medical uses. Papers presented at the Alzheimer's Association International Conference, which took place this month in Vancouver, indicate that changes in how elderly people walk, such as variable stride or slowing pace, can provide early signs of dementia. Should this prove to be true, it could have tremendous value in preventing and fighting the condition.

According to Gray, the technology is not as invasive as eye scans and other types of biometrics, partly because the individual data stays inside the bio-soles. On the other hand, one group that has followed biometrics and privacy issues believes the concept could still cause serious problems.

"Any biometric capture device is a potential tracking device, just like every iPhone is a potential tracking device," said Lee Tien, an attorney with the San Francisco-based nonprofit organization Electronic Frontier Foundation that monitors free speech and privacy issues. Tien reckoned that the biometric soles "might make a person feel a little bit better" than other security systems, and acknowledged that Gray's claim that the system can ID an individual within three steps is "pretty impressive." He did, however, raise concerns that if the project proves successful, such bio-soles could also be implanted in shoes secretly. "I wouldn't expect Nike to build these in. But it's potentially covert," said Tien, hinting that the system could be used to spy on people.