Submitted To:-Submitted By: - Biometric: MR. Harjeet Singh Ravinder Kumar
Submitted To:-Submitted By: - Biometric: MR. Harjeet Singh Ravinder Kumar
Submitted To:-Submitted By: - Biometric: MR. Harjeet Singh Ravinder Kumar
Biometric
Biometrics refers to the study of methods for uniquely recognising humans based on inherent
physical or behavioural traits.
In the Identity Society they will become an increasingly important Authentication method,
particularly in combination with other methods (or in technology speak "Authentication form
factors") because of the growing importance of seeing the real person behind applications and
devices. An example of a physical Biometric method are finger or face recognition. Voice
recognition combines both physical and behavioural methods.
Good knowledge based recognition could be described as exclusively behavioural thanks to the
uniqueness of the "memes" we all store in our brains.
The issue of "binding" is particularly strongly solved with Biometrics thanks to the decisiveness of
what or who you "are" which is irrevocably established.
Biometrics are highly emotive when it comes to identity, thanks to the sci-fi implications of
blending our physical and logical selves, and the imaginative threads unravelling from such
imagery. Also because of the sense of invasiveness from allowing someone your most personal
data. The recent advancements in DNA have introduced a possibly powerful new biometric method.
Biometrics consists of methods for uniquely recognizing humans based upon one or more intrinsic
physical or behavioral traits. In computer science, in particular, biometrics is used as a form of
identity access management and access control. It is also used to identify individuals in groups that
are under surveillance.
Biometric characteristics can be divided in two main classes:
• Physiological are related to the shape of the body. Examples include, but are not limited to
fingerprint, face recognition, DNA, Palm print, hand geometry, iris recognition, which has
largely replaced retina, and odour/scent.
• Behavioral are related to the behavior of a person. Examples include, but are not limited to
typing rhythm, gait, and voice. Some researchers have coined the term behaviometrics for
this class of biometrics.
Strictly speaking, voice is also a physiological trait because every person has a different vocal tract,
but voice recognition is mainly based on the study of the way a person speaks, commonly classified
as behavioral.
The basic block diagram of a biometric system
It is possible to understand if a human characteristic can be used for biometrics in terms of the
following parameters:
• Universality – each person should have the characteristic.
• Uniqueness – is how well the biometric separates individuals from another.
• Permanence – measures how well a biometric resists aging and other variance over time.
• Collectability – ease of acquisition for measurement.
• Performance – accuracy, speed, and robustness of technology used.
• Acceptability – degree of approval of a technology.
• Circumvention – ease of use of a substitute.
A biometric system can operate in the following two modes:
• Verification – A one to one comparison of a captured biometric with a stored template to
verify that the individual is who he claims to be. Can be done in conjunction with a smart
card, username or ID number.
• Identification – A one to many comparison of the captured biometric against a biometric
database in attempt to identify an unknown individual. The identification only succeeds in
identifying the individual if the comparison of the biometric sample to a template in the
database falls within a previously set threshold.
The first time an individual uses a biometric system is called an enrollment. During the enrollment,
biometric information from an individual is stored. In subsequent uses, biometric information is
detected and compared with the information stored at the time of enrollment. Note that it is crucial
that storage and retrieval of such systems themselves be secure if the biometric system is to be
robust. The first block (sensor) is the interface between the real world and the system; it has to
acquire all the necessary data. Most of the times it is an image acquisition system, but it can change
according to the characteristics desired. The second block performs all the necessary pre-
processing: it has to remove artifacts from the sensor, to enhance the input (e.g. removing
background noise), to use some kind of normalization, etc. In the third block necessary features are
extracted. This step is an important step as the correct features need to be extracted in the optimal
way. A vector of numbers or an image with particular properties is used to create a template. A
template is a synthesis of the relevant characteristics extracted from the source. Elements of the
biometric measurement that are not used in the comparison algorithm are discarded in the template
to reduce the filesize and to protect the identity of the enrollee.
If enrollment is being performed, the template is simply stored somewhere (on a card or within a
database or both). If a matching phase is being performed, the obtained template is passed to a
matcher that compares it with other existing templates, estimating the distance between them using
any algorithm (e.g. Hamming distance). The matching program will analyze the template with the
input. This will then be output for any specified use or purpose (e.g. entrance in a restricted area).
Performance
Cancelable biometrics
One advantage of passwords over biometrics is that they can be re-issued. If a token or a password
is lost or stolen, it can be cancelled and replaced by a newer version. This is not naturally available
in biometrics. If someone’s face is compromised from a database, they cannot cancel or reissue it.
Cancelable biometrics is a way in which to incorporate protection and the replacement features into
biometrics. It was first proposed by Ratha et al.
Several methods for generating cancelable biometrics have been proposed. The first fingerprint
based cancelable biometric system was designed and developed by Tulyakov et al. Essentially,
cancelable biometrics perform a distortion of the biometric image or features before matching. The
variability in the distortion parameters provides the cancelable nature of the scheme. Some of the
proposed techniques operate using their own recognition engines, such as Teoh et al. and Savvides
et al., whereas other methods, such as Dabbah et al., take the advantage of the advancement of the
well-established biometric research for their recognition front-end to conduct recognition. Although
this increases the restrictions on the protection system, it makes the cancellable templates more
accessible for available biometric technologies.
Soft biometrics
Soft biometrics because of their inner nature are privacy preserving. They allow to describe a
subject starting from his/her physical attributes. Those attributes have a low discriminating power,
thus not capable of identification performance, additionally they are fully available to everyone (e.g.
height, weight, gender) which makes them privacy-safe.