Biometrics refers to the measurement of specific physical or behavioral characteristics and the use of that data in identifying subjects. With wide application, biometricbased identification techniques are increasingly an important part of physical and financial security infrastructure because biometric data is difficult, if not impossible, to duplicate or otherwise falsify. Accordingly, biometric systems offer highly accurate means of comparison of measured characteristics to those in a preassembled database.

Biometric identification points include gross morphological appearance that is most often subjectively interpreted upon superficial examination (e.g., gender, race or color of skin, hair and eye color). Other gross biometric data can include more quantifiable—and therefore less subjective—data (e.g., weight, height, location of scars or other visible physical markings).

Some biometric data are easily changeable and therefore not reliable (e.g. presence of facial hair, wearing of glasses, etc.).

Because even objective features such as weight can change over time, systems of identification that rely on changeable or gross features are not as reliable as biometric systems that measure more stable anatomical and physiological characteristics such as fingerprints, retinal blood vessel patterns, specific skull dimensions; dental and skeletal x-rays, earlobe capillary patterns and hand geometry.

The most specific and reliable of biometric data are obtained from DNA sequencing.

More controversial and, at present, less reliable biometric studies seek to enhance quantification of social behaviors, voice characteristics—including language use patterns and accents—handwriting and even keystroke input patterns.

Biometric data can be encoded into magnetic stripes, bar codes, and integrated circuit "smart" cards.

On a global scale, biometric data interchange and interoperability standards are at present fragmented into different measurement and input format schemes. The Common Biometric Exchange File Format (CBEFF), in development by the International Biometric Industry Association (IBIA), seeks to integrate such measurement schemes to enhance reliability and use of biometric data. Other integration efforts include the Biometric Application Programming Interface (BioAPI) specification program used by the United States Department of Defense. The Department of Defense has also established a Biometrics Management Office (BMO). BioAPI protocols are also being used by other governmental agencies and the financial service industry in the development of smart cards.

In the private sector, specific organizations regulate need-driven biometric integration schemes. For example, the American National Standards Institute (ANSI) establishes specific biometric standards for the financial industry.

One system already with broad integration is used by the American Association for Motor Vehicle Administration (AAMVA). The Driver's License and Identification (DL/ID) standards are used to provide rapid and accurate identification based upon data gathered during the issuance of a driver's license within Canada or the United States.

The National Institute of Standards and Technology (NIST) also has programs dedicated to biometric research and exchange. NIST developed the initial data protocols used in the Face Recognition Vendor Test (FRVT) and established the format for data collection used by most face recognition technologies.



Jain, A., A. Bolle, and S. Pankanti. Biometrics, Personal Identification in Networked Society. Norwell, MA: Kluwer Academic Publishers, 1999.


Podio F., et al. "Common Biometric Exchange File Format (CBEFF)." NISTIR 6529 (January 3, 2000).


NIST Biometric Interoperability, Performance and Assurance Working Group (May, 2003) < > (May, 10, 2003).


APIS (Advance Passenger Information System)
Closed-Circuit Television (CCTV)
Facility Security
Fingerprint Analysis
Forensic Voice and Tape Analysis
IBIS (Interagency Border Inspection System)
IDENT (Automated Biometric Identification System)
INSPASS (Immigration and Naturalization Service Passenger Accelerated Service System)
Los Alamos National Laboratory
NAILS (National Automated Immigration Lookout System)
NIST (United States National Institute of Standards and Technology)
PORTPASS (Port Passenger Accelerated Service System)
Retina and Iris Scans
SENTRI (Secure Electronic Network for Travelers' Rapid Inspection)

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