Types of Biometric Authentication

Fingerprints are the most common type of biometric authentication.

In his article, "Biometric Authentication, An Introduction," Keith Palmgren defines biometrics as measurable physical or behavioral characteristics that can be used to verify a person's identity. Other methods of identity verification employ something a person knows, such as a password, or something a person has, such as a key or card. By employing something that is an integral part of the person, biometric authentication climbs to a cut above the other two methods.

Fingerprints and Hand Geometry

Fingerprint verification is the most common type of biometric authentication currently in use. Fingerprint scanners have the advantage of being small, low-cost, easy to implement and highly accurate. On the downside, cuts or dirt on the fingers or improper orientation of the finger on the scanner can cause false negatives. It is also possible for the user to use an image of a fingerprint instead of a real finger on some systems.

Hand or palm geometry focuses on the lengths and angles of the hand and the fingers. It is very user friendly but can be cumbersome.

Voice Recognition

Voice recognition systems look for voice pattern matches and should not be confused with speech recognition, which interprets what is said. Voice recognition systems have the advantage of being user friendly, but such things as background noise and changes to the voice due to colds, sinus congestion, anxiety, etc. can result in false negatives. Voice recognition systems also require a great deal of disk space, and entering an individual into the system is time consuming.

Eye Scans

Two types of eye scan are retinal and iris scans.

There are two different types of eye scans: retinal and iris, and they use two different technologies. Retinal scanning scans the patterns of the retina, in the interior of the eye. It is a highly accurate and well-established security method. It requires that the user make physical contact with the scanner, which raises hygiene problems, and for an accurate reading, the user must hold a focus on a particular point. Additionally, although the scan uses harmless, low-intensity light, users may have concerns about safety.

Iris scanning involves scanning the patterns of the iris, the colored part of the eye. The scan can be done at a distance and without removal of eyeglasses. The images used by iris scans are larger than retinal scan images and so require more storage space.

Facial Recognition

Facial recognition systems are the newest biometric authentication technology. They look for distinctive facial features such as the location and shape of the nose and eyes, the sides of the mouth, cheekbones, etc. The technology is still being developed, and as of now it works best when comparing two static images. Palmgren notes that successful implementation of facial recognition systems has been limited.

Signature Dynamics and Typing Patterns

Signature dynamics systems look for patterns in the writing speeds and pressures at different points in the signature. Typing pattern recognition systems look for patterns in the intervals between typed characters and the overall typing speed. While these methods can be effective, there are problems with long-term reliability.

References

• SecurityDocs.com: Biometric Authentication, An Introduction
• Computerworld: QuickStudy: Biometric authentication
• ResearchWeb: Biometrics: A Further Echlon of Security

Resources

• Advances in Biometrics: Third International Converence, ICB 2009: Proceedings; Tistarelli, Nixon