Principles of hand biometrics
An individual's hand does not significantly change after a certain age. Unlike fingerprints, the human hand isn't unique. Individual hand features are not descriptive enough for identification. However, hand biometric recognition systems are accurate for verification purposes when combining various individual features and measurements of fingers and hands.
How does hand biometrics work
Biometric hand recognition systems measure and analyze the overall structure, shape and porportions of the hand, e.g. length, width and thickness of hand, fingers and joints; characteristics of the skin surface such as creases and ridges. Some hand geometry biometrics systems measure up to 90 parameters.
As hand biometrics rely on hand and finger geometry, the system will also work with dirty hands. The only limitation is for people with severe arthristis who cannot spread their hands on the reader.
The user places the palm of his or her hand on the reader's surface and aligns his or her hand with the guidance pegs which indicate the proper location of the fingers. The device checks its database for verification of the user. The process normally only takes a few seconds.To enroll, the users places his or her hand palm down on the reader's surface.
To prevent a mold or a cast of the hand from being used, some hand biometric systems will require the user to move their fingers. Also, hand thermography can be used to record the heat of the hand, or skin conductivity can be measured.
Benefits of hand biometric systems
- Easy to use
- Non intrusive
- Small amount of data required to uniquely identify a user, so a large number of templates can be easily stored in a standalone device: Hand biometric systems will generally only require a template size of 10 bytes, which is much smaller than most other biometric technologies (fingerprint systems require 250 to 1,000 bytes and voice biometric systems require 1,500 to 3,000 bytes)
- Low FTE (failure to enroll) rates
Weaknesses of hand biometric systems
- Lack of accuracy, so it can only be used for verification
- Size of the scanner
- Fairly expensive, compared with fingerprint systems
- Injuries to hands are fairly common and would prevent the hand biometric system from working properly
Applications of hand biometrics
Hand biometric systems are currently among the most widely used biometric technologies.
- Time and attendance
- Access to restricted areas and buildings: Hand biometric systems are currently used in appartment buildings, offices, airports, day care centers, welfare agencies, hospitals, and immigration facilities.