What is a biometric?
The three main types of authentication available today
are:
- something you know – e.g. a password, a PIN,
or a code
- something you have – e.g. a swipe card, smart
card, a token or a key
- something you are – a biometric
Of these biometrics is the most secure and convenient
for authentication. It can’t be taken, borrowed,
forgotten or written down.
Biometrics involves measuring an individual’s
unique physical or behavioural characteristics to determine
or verify their identity. Common physical biometrics
include fingerprints, hand or palm geometry, face, iris
or retina. The most widely used physical biometric is
fingerprint.
Behavioural biometrics include signature, voice (with
a physical aspect), keystroke pattern and gait. Of this
class the most developed technologies are signature
and voice.
Why Use Biometrics?
Greater security and convenience
- Convenience: nothing to lose or forget
- Security: cannot be guessed, transferred or stolen
and is unique
Higher productivity and lower
costs
- No one is locked out because of lost cards or forgotten
or expired passwords
- Less support calls.
Studies have shown that maintaining Windows passwords,
for example, costs companies $150 per user, per year.
Fingerprint Biometrics
Fingerprint biometrics is based on the patterns on
the fingerprint which have been used for identification
purposes for centuries. There are a variety of techniques
and systems which use the unique features of the fingerprint
to identify it. Some of these features are-
- Minutiae points. These are the points where fingerprint
ridges lines start, stop, or fork. A typical fingerprint
has around 70 minutiae points
- Ridge pattern/density
- Core area
- Delta
- Type Lines
Hand Geometry
Hand geometry biometrics involves analysing and measuring
the hand’s shape. This uses the overall geometry
of the hand, not individual fingerprints. This biometric
is relatively easy to use. It could be suitable where
the system is used infrequently or where users are somewhat
less disciplined in their use of it.
Accuracy can be good and it can be used for a wide
range of applications. Hand geometry has been popular
for time clocking and access control.
Iris
Iris scan biometrics looks at the features found in
the rings of tissue surrounding the pupil. Iris scan
uses a camera and does not require close contact between
the user and the sensor. It has the potential for high
recognition performance and can work while the user
is wearing glasses.
Face
Face recognition analyses the characteristics of the
face. This technique has attracted a lot of interest
but has generally only been used to date for some specialised
applications such as within airports or casinos. Face
scan requires more elaborate hardware and is more expensive than other
popular biometrics.
Biometric Recognition Performance
The performance of a biometric system can be characterised
by the:
- False Acceptance Rate (FAR): This is the probability
that an intruder or someone not entitled to access
is accepted by the system. This constitutes a serious
security breach. For finger, hand and iris systems
this ranges from 0.1% - 0.000001%. Many users of such
systems find they are now perfect are for all practical
purposes.
- False Rejection Rate (FRR): This is the probability
that a legitimate user will be rejected by the system.
This is not really a security breach but is an annoyance
for the user (since it requires a second attempt).
For a typical fingerscan system it is 1% - 0.1%.
Components of Biometric System
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