How Do Biometric Security Systems Work?

Biometrics measure various physical or behavioral traits for security purposes.

Biometrics is the use of physical or behavioral attributes as a password or key. You've probably seen fingerprint or eye scanners in popular Hollywood spy movies, but this technology is real and provides an outstanding level of security. Biometrics work by recording a physical or behavioral trait such as fingerprint or voice. It then uses these recordings as a password so the person must provide, for instance, the same fingerprint or voice to gain access to private information, data or locations.

Fingerprint Recognition

The fingerprint is truly unique to each individual, so there's little chance of a security breach when this technology is in use. Minutiae based systems scan for specific minutiae (precise details) of the fingerprint and match it against prints in the database. Correlation systems superimpose the image of a scanned print onto prints in the database, looking for a match. Ridge capturing systems measure the specific ridges and raises in fingerprints; this advanced system works best with low-quality samples.

Eye Recognition

Eye recognition is similar to fingerprint systems, but uses specific colors, rings and lines in a person's eye as a "key" or "password." A well-known eye recognition system is the iris scanner, which scans the colored part of person's eye in extreme detail, a human feature as unique to each individual as the fingerprint. The color, rings and spots of the iris are matched against a database for matches. Retinal scanning is more advanced and takes an infrared image of a person's eye and searches for database matches based on blood vessels in the eye.

Facial Recognition

Another physical biometric method, facial recognition uses a person's entire face. Geometric facial scanners scan things like the shape of the person's nose, mouth and eyes and their distance from each other. A more advanced facial recognition system is facial thermogram recognition, which scans faces with infrared light searching for heat signatures. Research Web claims that this system cannot be fooled by disguises or even plastic surgery. For even further security, many facial scans require the person to blink, smile or move in a manner that proves they're human and not a detailed mask.

Voice Recognition

Voice recognition is an example of a system that scans a behavioral attribute. Vocal recognition systems measure frequency, timing, tone, inflection and speech patterns to match a person's voice to one in the database. The person either pre-programs or is given a word or phrase by the security system itself to repeat to test voice patterns. Advanced systems don't require the articulation of any specific word or phrase, meaning they can be used by people of different languages.

Signature Recognition

Another behavioral attribute test, signature recognition, has been used for validation of identity before biometrics were even around. Biometrics simply improves the accuracy of such systems, as a camera matching a signatures specific characteristics against a database image is much more accurate than the human eye. That said, this method can be forged by professional forgers and people's signatures naturally change over time, making this method not as secure as many of the other methods available.

References

• Research Web: Biometrics: A Further Echelon of Security
• NC SC: An Overview of Biometrics