A biometric technology that requires an employee to have direct contact with an electronic device (scanner) will be referred to a contact biometric. The very nature of a contact biometric is that a person requiring access is to make direct contact with an electronic device to attain physical or logical access. Because of the inherent need of a person to make direct contact, many people have come to consider a contact biometric to be a technology that intrudes into personal space and to be interfering to personal privacy.

Hand/Finger Geometry
Hand or finger geometry is an automated measurement of many measurements of the hand and fingers. None of these methods takes actual prints of fingers or palm. The hand image is made using a camera looking from the top when the user places hand at a special surface. The hand can be aligned using pegs or reference marks. Two views are usually taken in a single image, the top view and the side view. The side view is usually taken by the top camera as well using a side mirror. From the hand image, the fingers are located and the length, width, thickness, curvatures and their relative geometry measured. Finger geometry templets are typically 20 to 25 bytes, and hand geometry templets 9 bytes. Finger geometry usually measures two or three fingers. Hand geometry is a well-developed technology that has been thoroughly field-tested and is easily accepted by users.

Fingerprint
The fingerprint biometric is an automated digital version of the old ink-and-paper method used for more than a century for identification. Fingerprint has been used since 1896 for criminal identification and it is the oldest method of identity authentication. The biometric device involves platen, for the user’s finger to be placed and read.

The fingertips have grooved skin with line like ridges flowing from one side of the finger to another. The ridges are non-continuous and form a pattern. The intermittence in the ridge flow give rise to feature points, called minutiae, while the pattern of flow give rise to classification pattern such as arches, loops and whorls. These are the basis of fingerprint recognition.

The image is then extracted by the system’s algorithm, which also makes a fingerprint pattern analysis. Fingerprint templet size varies from 50 to 1000 bytes. Fingerprint biometrics currently have three main application areas: extensive Automated Finger Imaging Systems (AFIS) usually used for law enforcement purposes, fraud prevention in entitlement programs and physical and computer access.

In general, fingerprint recognition can achieve good accuracy sufficient for both verification and identification. It is low cost and compact and is getting popular as consumer products. However, not everyone has fingerprints that can be recognized. The sensor is also not able to capture acceptable quality fingerprint images for people with very wet and very dry skin. In addition, the sensor needs to be maintained properly in order to get consistent performance. Fingerprints have the most potential in terms of user authentication. It was recently concluded by The Spring 2002 international developer survey.

Keystroke Dynamics
Keystroke dynamics is an automated method of examining an individual’s keystrokes on a keyboard. This technology examines such characters as pressure and speed, the total time of typing a password and the time a user takes between hitting certain keys. One potentially useful application that may emerge is computer access, where this biometric could be used to verify the computer user’s identity. This technology’s algorithms are still being developed to improve reliability and quality.

Dynamic Signature Verification
It is an automated method of examining an individual’s signature. This technology scans such dynamics as speed, direction and pressure of writing; the time that the stylus is in and out of contact with the “paper”; the total time taken to make the signature; and where the stylus is raised from and lowered onto the “paper.” Dynamic signature verification templates are typically 50 to 300 bytes.