Facial and hand modalities are two forms of biometric inputs. Facial recognition usually requires a sensor (such as a camera) to verify a person's unique facial features. Hand geometry is a lot like fingerprinting, and uses technology to recognize a person's unique skin patterns on their palms. Facial and hand modalities require large amounts of physical space within a security computer system in order to be effective.
Voice modalities use telephones or microphones to record (input) and recognize an individual's speech pattern. Voice modality recognizes the speaker and not the words that they communicate. Iris recognition is a biometric input that uses verifies a unique pattern of blood vessels within an individual's retina for the purpose of identification. There are some public health concerns about using this biometric scanning technology on the eyes. Iris recognition technology has been implemented in some biometric systems but is still being developed.
Behavior biometrics is another way to input data into a security system and it can identify a person over a period of time through their unique actions. Data for behavior biometrics records a person's physical actions (that is, how they walk or move) and their keystroke and signature dynamics. This technology inputs a person's actions and characteristics and then matches it up against a template of their actions. Fingerprinting is a traditional security measure and is another common type of biometric input.
