There are several categories of biometric authentication methods.
Biometric Authentication Method and Description
A user’s ﬁngerprint pattern is scanned and stored. To authenticate, the user scans a ﬁnger again and the print is compared to the stored image in the authentication database. The ﬁngerprint scanner can be a small separate hardware device, and is even built into some laptops, mice, and USB ﬂash drives.
Hand geometry scanner:
An individual’s hand geometry can also be used for authentication. Hand scanners have pegs between which users insert their ﬁngers. Once the initial scan is stored, and then used to authenticate, subsequent scans are compared to the stored scan in the authentication database.
The pattern on a user’s retina is scanned and stored. To authenticate, the user scans an eye again and the pattern is compared to the authentication database.
The user provides a speech sample that is analyzed with voice-recognition software and stored. To authenticate, the user speaks again and the speech patterns are analyzed by the software and compared against the stored sample in the authentication database.
A digital image of the user’s face is analyzed with face-recognition soft- ware and stored. To authenticate, the user’s face is scanned digitally again and the facial appearance is compared against the stored image in the authentication database.
Biometric authentication tokens:
Biometric user data can be scanned and encoded once and then stored on a chip on some form of portable electronic security token such as a smart card or a digital keyfob. To authenticate, the user presents the token instead of submitting to another biometric scan. Because the token could be lost or stolen, it is best to combine this type of authentication with a password or PIN, or at least to include a user photograph on the card for visual conﬁrmation of the user’s identity.