The ‘123’ of Biometric Technology 83 Section Three The ‘123’ of Biometric Technology We are so used to recognising people in our daily life that we often take this task for granted. Despite the often heard problems of fraud in the electronic transactions over the Internet in which lack of identity authentication is a prime cause, automated identity authentication afforded by biometric technology is not looked into seriously by most corporations. However, after the September 11 incident, biometric technology is gaining in popularity. This article will give an overview of this technology, its potential, issues and challenges to widespread adoption. Yau Wei Yun Research Manager, Laboratories for Information Technology Co-Chair, Biometrics Working Group of Security & Privacy Standards Technical Committee 1. Introduction One of the remarkable ability of human and most animals is to identify friends from foes. Such capability is crucial for survival from ancient time till now. Why is it so? Wrongly identifying a foe as a friend could mean goodwill abused, property or wealth stolen, valuable information lost to unwanted hands, life of oneself and family members jeopardised or in larger scale, the society or nation threatened. The reverse will equally cost one dearly in societal and personal relationship. If you think about it, our capability to recognise people has been developed since young and is used daily - we recognise our family members, friends and foes, primarily through face and voice. Our daily transactions, from purchasing things at the nearby convenience stores, withdrawing small amount of money at the Auto-Teller Machines, entering our house or office to large monetary transactions at a bank involves our identity and the means of authenticating it. Indeed, it is pervasive in our daily life. Even in the current Information Technology (IT) age, identity authentication is very crucial. IT brings with it capability for electronic transaction where face-to-face or other means of personal contact is not necessary. The lack of actual contact makes identifying the real user necessary as well as difficult. Necessary because as the saying goes, in the Internet, even a monkey can be human! Difficult as it goes beyond the traditional means of identity authentication and where being anonymous and staying anonymous is the desired feature of the Internet.
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Transcript
The
‘123
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Biom
etric
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83
Sect
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The ‘123’ of Biometric TechnologyWe are so used to recognising people in our daily life that we often take this task for granted. Despite
the often heard problems of fraud in the electronic transactions over the Internet in which lack of
identity authentication is a prime cause, automated identity authentication afforded by biometric
technology is not looked into seriously by most corporations. However, after the September 11 incident,
biometric technology is gaining in popularity. This article will give an overview of this technology, its
potential, issues and challenges to widespread adoption.
Yau Wei YunResearch Manager, Laboratories for Information Technology
Co-Chair, Biometrics Working Group of Security &
Privacy Standards Technical Committee
1. Introduction
One of the remarkable ability of human and most animals is to identify friends from foes. Such
capability is crucial for survival from ancient time till now. Why is it so? Wrongly identifying
a foe as a friend could mean goodwill abused, property or wealth stolen, valuable information
lost to unwanted hands, life of oneself and family members jeopardised or in larger scale, the
society or nation threatened. The reverse will equally cost one dearly in societal and personal
relationship. If you think about it, our capability to recognise people has been developed since
young and is used daily - we recognise our family members, friends and foes, primarily through
face and voice. Our daily transactions, from purchasing things at the nearby convenience
stores, withdrawing small amount of money at the Auto-Teller Machines, entering our house
or office to large monetary transactions at a bank involves our identity and the means of
authenticating it. Indeed, it is pervasive in our daily life.
Even in the current Information Technology (IT) age, identity authentication is very crucial.
IT brings with it capability for electronic transaction where face-to-face or other means of
personal contact is not necessary. The lack of actual contact makes identifying the real user
necessary as well as difficult. Necessary because as the saying goes, in the Internet, even a
monkey can be human! Difficult as it goes beyond the traditional means of identity authentication
and where being anonymous and staying anonymous is the desired feature of the Internet.
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Traditional means of identity authentication using tokens such as keys and cards, or
personal identification numbers (PINs) and passwords are ill suited for such a task. For
example, if you would like to purchase anything in the Internet, most likely you will
require a credit card number to authenticate who you are and that you have means
to pay for your goods. However, such a number can be obtained rather easily by hackers,
not to mention the numerous fake credit cards in circulation. Bank cards need PINs to
authenticate one's identity. However, in many situations, the PINs can be obtained
easily either because the users wrote the PINs behind their cards or at some place or
that the PINs were obtained through observation or fraudulent means. Some users have
more than one bank account and thus it is challenging to remember all the PINs on
top of the various PINs/passwords used daily. The most important issue is how to identify
the "real" person without resorting to any complex and troublesome mechanism for
verification. Biometrics is seen as one of the best candidates to solve this problem.
Essentially, biometrics is the automated approach to authenticate the identity of a
person using the individual's unique physiological or behavioural characteristics such
as fingerprint, face, voice, signature etc. Since it is based on a unique trait which is
part of you, you do not have to worry about forgetting it, losing it or leaving it at some
place. Since it is unique to you, it is more difficult for others to copy, duplicate or steal
it. Thus in general, biometrics offers a more secure and friendly way of identity
authentication.
2. Biometrics
There are several biometric technologies in use today with a few more technologies
being investigated in research laboratories worldwide [1, 2]. Nevertheless, all the
technologies share a common process flow as follows:
Figure 1: Common Biometric Process Flow
Processing:Extract Features andGenerate Template
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A sensor is required to acquire the biometric data that will then be processed by a processor
which could be part of an embedded system or a PC. The processing involves enhancing the
data, removing noise and segmenting out the crucial data. From such conditioned data, the
unique features are then extracted and a template is then generated to represent the biometric
data. This template will be the basis from which the uniqueness of the data is associated with
the identity of the user. If it is the first time the user is using the biometric system, the template
will be stored for future references. Other information associated with the user may be included
as well. User access to the system involves comparing the generated template against the
reference of allowed user(s). If the matching is made against a claimed identity, the matching
process will be a one to one comparison between the generated template and the stored
reference template. Such a matching process is called a verification process. There are many
ways to claim an identity, such as by entering name, telephone number, PIN or password and
using token such as smart card or contactless card.
Another possible mode of matching is to compare the generated template against a list of
reference templates of legitimate users. Such a process involves one to many comparisons and
the matching process is called an identification process. The type of matching process used
in a biometric system will depend on the nature of application where the biometric system
is used and the biometric technology involved, as not all biometric technology is suitable for
identification. The following sections will discuss the common biometric technology such as
face, fingerprint, hand geometry, iris, and voice.
3. Face
A face image can be acquired using a normal camera such as an off-the-shelf desktop camera.
As such, it is the most natural biometric for identity authentication. Two main approaches are
used to perform face recognition, namely holistic or global approach and feature-based
approach [3].
Feature-based approach rely on the identification of certain fiducial points on the face which
are less susceptible to alteration, including the points at the eyes, the side of the nose and
the mouth, the points surrounding one's cheekbones etc. The locations of these points are
used to compute the geometrical relationships between the points. The regions surrounding
the points can be analysed locally as well. Results from all the local processing at the fiducial
points are then combined to obtain the overall face recognition. Since detection of feature
points precedes the analysis, such a system is robust to position variations in the image.
However, automatic detection of the fiducial points is not accurate and consistent enough
to yield a high accuracy rate for the face recognition.
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Holistic approach processes the entire face image simultaneously without attempting
to localise the individual points. This approach has some variants in the type of
technology used, such as statistical analysis, neural networks or transformations. The
famous examples for statistical analysis are the eigenface technique [5] and local
feature analysis [6] while for neural network is the elastic bunch graph matching
technique [7]. The advantage of holistic approach is that it utilizes the face as a whole
and does not destroy any information by exclusively processing only certain fiducial
points. This generally yields more accurate recognition results. However, such technique
is sensitive to variations in position and scale, and thus requires large training data