In information technology, biometric authentication refers to technologies that measure and analyze human physical and behavioural characteristics for authentication purposes. Examples of physical characteristics include fingerprints, eye retinas and irises, facial patterns and hand measurements, while examples of mostly behavioural characteristics include signature, gait and typing patterns. Voice is considered a mix of both physical and behavioural characteristics. However, it can be argued that all biometric traits share physical and behavioural aspects.   Biometrics   Wikipedia, the free encyclopedia

Imagine you're James Bond, and you have to get into a secret laboratory to disarm a deadly biological weapon and save the world. But first, you have to get past the security system. It requires more than just a key or a password -- you need to have the villain's irises, his voice and the shape of his hand to get inside. You might also encounter this scenario, minus the deadly biological weapon, during an average day on the job. Airports, hospitals, hotels, grocery stores and even Disney theme parks increasingly use biometrics -- technology that identifies you based on your physical or behavioral traits -- for added security.   How Biometrics Work  How Stuff Works

Computerized fingerprint scanners have been a mainstay of spy thrillers for decades, but up until recently, they were pretty exotic technology in the real world. In the past few years, however, scanners have started popping up all over the place -- in police stations, high-security buildings and even on PC keyboards. You can pick up a personal USB fingerprint scanner for less than $100, and just like that, your computer's guarded by high-tech biometrics. Instead of, or in addition to, a password, you need your distinctive print to gain access.   How Fingerprint Scanners Work   How Stuff Works

A ticket to Super Bowl XXXV in Tampa Bay, Florida, didn't just get you a seat at the biggest professional football game of the year. Those who attended the January 2000 event were also part of the largest police lineup ever conducted, although they may not have been aware of it at the time. The Tampa Police Department was testing out a new technology, called FaceIt, that allows snapshots of faces from the crowd to be compared to a database of criminal mugshots.   How Facial Recognition Systems Work   How Stuff Works

Your voice is unique because of the shape of your vocal cavities and the way you move your mouth when you speak. To enroll in a voiceprint system, you either say the exact words or phrases that it requires, or you give an extended sample of your speech so that the computer can identify you no matter which words you say. When people think of voiceprints, they often think of the wave pattern they would see on an oscilloscope. But the data used in a voiceprint is a sound spectrogram, not a wave form. A spectrogram is basically a graph that shows a sound's frequency on the vertical axis and time on the horizontal axis. Different speech sounds create different shapes within the graph. Spectrograms also use colors or shades of grey to represent the acoustical qualities of sound. This tutorial has a lot more information on spectrograms and how to read them.   How Biometric Systems Work - More Biometric Systems  How Stuff Works

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