Fingerprints are the oldest biometric known, and are by far the most popular biometric identifier used in the world today. Fingerprints form in the womb and, barring injury, remain unique and consistent throughout life. For almost 150 years analyses of fingerprints have been an important part of criminal investigations and identification of individuals. Until recently, the capture of fingerprints has been more art than science, and their comparison largely restricted to highly trained specialists. Using small digital imaging devices that can be mounted beside entrances, or even built into computer keyboards, fingerprints can now be captured, digitised into mathematical descriptions, encrypted and compared by computers against databases.

Whereas once fingerprints had to be captured with ink on paper and sent through the mail or faxed to central repositories for specialized study, the entire process can now be done in near real time. The uniqueness of fingerprints and wide acceptance and understanding of the technology has resulted in fingerprint-based biometric technology being employed to automate processes in numerous areas that previously required significant administrative resources, such as time and attendance, access control, etc.