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Hand Geometry System Hand geometry data, the three-dimensional record of the length, width, and height of the hand and fingers is acquired by simultaneous vertical and horizontal camera images. Enrollment Procedure and Time The subject is directed to place the hand flat on a grid platen, positioned against pegs between the fingers. Four finger-position lights ensure proper hand location. A digital camera records a single top and side view from above, using a 45º mirror for the side view. The subject is directed to withdraw and then reposition the hand twice more. The readings are averaged into a single code and given a PIN. Total enrollment time is less than 2 minutes. Template or File Size The hand geometry user file size is nine bytes. User Actions Required The hand geometry system operates only as an identification verifier. The user states identification by entering a PIN on a keypad or by using a card reader. When the “place hand” message appears on the unit display, the user places the hand flat on the platen against the pegs. When all four lights confirm correct hand position the data are acquired and a “remove hand” message appears. System Response Time Visual and audible annunciation of the confirm or not confirm decision occurs in 3 to 5 seconds. Anticounterfeit Method The manufacturer states that “the system checks to ensure that a live hand is used.” Accuracy Sandia National Laboratories tests have produced a one-try false accept rate less than 0.1%, a three-try false reject rate less than 0.1%, and crossover error rates of 0.2 and 2.2% (i.e., two tests). Field History Thousands of units have been fielded for access control, college cafeterias and dormitories, and government facilities. Hand geometry was the original biometric system of choice of the Department of Energy and the Immigration and Naturalization Service. It was also used to protect the Athlete’s Village at the 1996 Olympics in Atlanta. Problems Experienced Some of the field applications did not perform up to the accuracy results of the initial Sandia test. There have been indications that verification accuracy achieved when user data bases are in the hundreds deteriorates when the data base grows into the thousands. Unique System Aspects The hand geometry user file code of nine bytes is by far the smallest of any current biometric system. Hand geometry identification systems are manufactured by Recognition Systems, Inc. A variation, a two-finger geometry identification system is manufactured by BioMet Partners. Voice Pattern Systems Up to seven parameters of nasal tones, larynx and throat vibrations, and air pressure from the voice are captured by audio and other sensors. Enrollment Procedure and Time Most voice systems use equipment similar to a standard telephone. As directed, the subject picks up the handset and enters a PIN on the telephone keypad. When cued through the handset, the subject speaks his or her access phrase, which may be his or her PIN and name or some other four- to six-word phrase. The cue and the access phrase are repeated up to four times. Total enrollment time required is less than 2 minutes. Template or File Size Voice user files vary from 1,000 to 10,000 bytes, depending on the system manufacturer. User Actions Required Currently, voice systems operate only as identification verifiers. The user states identification by entering the PIN on the telephone-type keypad. As cued through the handset (i.e., recorded voice stating “please say your access phrase”), the user speaks into the handset sensors. System Response Time Audible response (i.e., “accepted, please enter” or “not authorized”) is provided through the handset. Some systems include visual annunciation (e.g., red and green lights or LEDs). Total transaction time is up to 10 to 14 seconds. Anticounterfeit Method Various methods are used including measuring increased air pressure when “p” or “t” sounds are spoken. Some sophisticated systems require the user to speak different words from a list of 10 or more enrolled words in a different order each time the system is used. Accuracy Sandia National Laboratories has reported crossover errors over 10% for two systems they have tested. Other voice tests are being planned. Field History Over 100 systems have been installed, with over 1,000 door access units, at colleges, hospitals, laboratories, and offices. Problems Experienced Background noise can affect the accuracy of voice systems. Access systems are located at entrances, hallways, and doorways, which tend to be busy, high-traffic, and high-noise-level sites. Unique System Aspects Some voice systems can also be used as an intercom or to leave messages for other system users. There are several companies producing voice-based biometric identification systems.
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