Some of the different types of biometric security technology available as of 2015 includes visual, behavioral, chemical, auditory and olfactory biometrics. A biometric security technology is a tool that can recognize or authenticate a person's identity by measuring the individual's unique physical or behavioral characteristics.
Visual biometrics are one of the most diverse groups and includes technologies such as iris, retina, fingerprint, face and ear recognition. There are also a number of visual/spatial biometrics, such as finger geometry and hand geometry recognition. While visual biometrics generally focus on physical characteristics, chemical biometrics identify a person based on an analysis of segments of their DNA.
Another common biometric security technology is signature recognition, which is a type of visual/behavioral biometric that allows the individual to be identified by a digital analysis of their signature. There are several other types of behavioral biometrics as well, including typing or keystroke recognition and gait recognition. Typing recognition seeks to identify a person based on their own unique typing characteristics, while gait recognition identifies a person based on their gait or style of walking.
Of the various types of biometric technologies, voice recognition and signature recognition are the most developed. Voice recognition is the main type of auditory biometric, which can be used to identify an unknown speaker or to authenticate the speaker's identity. Finally, there are even olfactory biometrics that can identify a person based on their individual odor.