Biometric Checks

A relatively new method of identification for computer systems is the biometric check. It consists of comparing some readily accessible and reliably unique physical characteristic of a human user against the system's stored values for that characteristic. Some commonly used biometrics are:

• hand proportions
• facial image
• retinal image
• finger prints
• voice print

• all the biometric sensors are relatively expensive, in both monetary and computing terms;
• measuring hands requires that the appropriate hand be free, ungloved, and that the user has a measurable hand;
• a facial image scan requires that the user's appearance not change drastically;
• a retinal image scan requires that the user has a measurable retina, that eyeglasses or a contact lens not interfere, and that the user is willing to allow the scanner's laser to scan their eye;
• fingerprint analysis has the same drawbacks as the hand proportion metrics;
• voice print analysis is affected by noise and throat problems, and requires that the user have a measurable voice.