22-03-2011, 04:55 PM
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BIOMETRICS
INTRODUCTION:
Biometrics refers to two very different fields of study and application. The first, which is the older and is used in biological studies, is the collection, synthesis, analysis and management of data in biology. Biometrics in reference to biological sciences, or biostatistics, has been studied since the early twentieth century. Biometrics is the science and technology of measuring and analyzing biological data. In information technology, biometrics refers to technologies that measure and analyze human body characteristics, such as fingerprints, eye retinas and irises, voice patterns, facial patterns and hand measurements, for authentication purposes.
More recently and incongruously, the term's meaning has been broadened to include the study of methods for uniquely recognizing humans based upon one or more intrinsic physical or behavioral traits. In information technology particularly, biometrics is a form of identity access management and access control.
Some researchers have coined the term behaviometrics for behavioral biometrics such as typing rhythm or mouse gestures where the analysis can be done continuously without interrupting or interfering with user activities.
Biometrics is used to identify the input sample when compared to a template, used in cases to identify specific people by certain characteristics.
i. possession-based
ii. using one specific "token" such as a security tag or a card
iii. knowledge-based
iv. The use of a code or password.
CLASSIFICATION:
Biometric characteristics can be divided in two main classes, as represented in figure on the right:
Physiological are related to the shape of the body. Examples include, but are not limited to fingerprint, face recognition, hand and palm geometry and iris recognition.
Behavioral are related to the behavior of a person. Characteristic implemented by using biometrics are signature verification, keystroke dynamics, and voice. The analysis and recognition of facial features is a tool used in the detection of criminals and undesirables. Conventional biometric methods introduced to improve security are mainly based on cross matching the face of the person with that recorded in their databases. At present, the data is static and would not, for example, identify suspects with cosmetic or plastic surgery modification of their faces to escape identification. However, it is possible to train persons that could be referred to as "face-minders", to memorized faces of suspects on a watch-list, by way of example.
Recently, a new trend has been developed that merges human perception to computer database in a brain-machine interface. This approach has been referred to as cognitive biometrics. Cognitive biometrics is based on specific responses of the brain to stimuli which could be used to trigger a computer database search. Currently, cognitive biometrics systems are being developed to use brain response to odor stimuli, facial perception and mental performance for search at ports and high security areas. .
Strictly speaking, voice is also a physiological trait because every person has a different pitch, but voice recognition is mainly based on the study of the way a person speaks, commonly classified as behavioral.
Other biometric strategies are being developed such as those based on gait (way of walking), retina, hand veins, finger veins, ear canal, facial thermo gram, DNA, odor and scent, palm prints and footprints.
BIOMETRICS:
The diagram on right shows a simple block diagram of a biometric system.
When such a system is networked together with telecommunications technology, biometric systems become telebiometric systems. The main operations a system can perform are enrollment and test. During the enrollment, biometric information from an individual is stored. During the test, biometric information is detected and compared with the stored information.
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 our 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 features needed are extracted. This step is an important step as the correct features need to be extracted and 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 all the characteristics extracted from the source, in the optimal size to allow for adequate identifiability.
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) .
BIOMETRICS
INTRODUCTION:
Biometrics refers to two very different fields of study and application. The first, which is the older and is used in biological studies, is the collection, synthesis, analysis and management of data in biology. Biometrics in reference to biological sciences, or biostatistics, has been studied since the early twentieth century. Biometrics is the science and technology of measuring and analyzing biological data. In information technology, biometrics refers to technologies that measure and analyze human body characteristics, such as fingerprints, eye retinas and irises, voice patterns, facial patterns and hand measurements, for authentication purposes.
More recently and incongruously, the term's meaning has been broadened to include the study of methods for uniquely recognizing humans based upon one or more intrinsic physical or behavioral traits. In information technology particularly, biometrics is a form of identity access management and access control.
Some researchers have coined the term behaviometrics for behavioral biometrics such as typing rhythm or mouse gestures where the analysis can be done continuously without interrupting or interfering with user activities.
Biometrics is used to identify the input sample when compared to a template, used in cases to identify specific people by certain characteristics.
i. possession-based
ii. using one specific "token" such as a security tag or a card
iii. knowledge-based
iv. The use of a code or password.
CLASSIFICATION:
Biometric characteristics can be divided in two main classes, as represented in figure on the right:
Physiological are related to the shape of the body. Examples include, but are not limited to fingerprint, face recognition, hand and palm geometry and iris recognition.
Behavioral are related to the behavior of a person. Characteristic implemented by using biometrics are signature verification, keystroke dynamics, and voice. The analysis and recognition of facial features is a tool used in the detection of criminals and undesirables. Conventional biometric methods introduced to improve security are mainly based on cross matching the face of the person with that recorded in their databases. At present, the data is static and would not, for example, identify suspects with cosmetic or plastic surgery modification of their faces to escape identification. However, it is possible to train persons that could be referred to as "face-minders", to memorized faces of suspects on a watch-list, by way of example.
Recently, a new trend has been developed that merges human perception to computer database in a brain-machine interface. This approach has been referred to as cognitive biometrics. Cognitive biometrics is based on specific responses of the brain to stimuli which could be used to trigger a computer database search. Currently, cognitive biometrics systems are being developed to use brain response to odor stimuli, facial perception and mental performance for search at ports and high security areas. .
Strictly speaking, voice is also a physiological trait because every person has a different pitch, but voice recognition is mainly based on the study of the way a person speaks, commonly classified as behavioral.
Other biometric strategies are being developed such as those based on gait (way of walking), retina, hand veins, finger veins, ear canal, facial thermo gram, DNA, odor and scent, palm prints and footprints.
BIOMETRICS:
The diagram on right shows a simple block diagram of a biometric system.
When such a system is networked together with telecommunications technology, biometric systems become telebiometric systems. The main operations a system can perform are enrollment and test. During the enrollment, biometric information from an individual is stored. During the test, biometric information is detected and compared with the stored information.
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 our 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 features needed are extracted. This step is an important step as the correct features need to be extracted and 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 all the characteristics extracted from the source, in the optimal size to allow for adequate identifiability.
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) .
