Source: http://www.buysec.no/Produkter/
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Contactless Biometric Technologies
A contactless biometric can either come in the form of a passive (biometric device continuously monitors for the correct activation frequency) or active (user initiates activation at will) biometric. In either event, authentication of the user biometric should not take place until the user voluntarily agrees to present the biometric for sampling. A contactless biometric can be used to verify a persons identity and offers at least two dimension that contact biometric technologies cannot match. A contactless biometric is one that does not require undesirable contact in order to extract the required data sample of the biological characteristic and in that respect a contactless biometric is most adaptable to people of variable ability levels.
Facial Geometry
Facial recognition systems are one of the fastest growing biometric technologies. A facial geometry system measures such characteristics as the distance between facial features (from pupil to pupil, for instance) or the dimensions of the features themselves (such as the width of the mouth).
In principle, the analysis of the face seems to be the best way to perform identity authentication and also the most acceptable to the public at large; for this is the most natural way for human beings to identify someone and we do it everyday. Not to mention, it is passive/non-intrusive. However, due to the perception of phantasmagoric privacy and the fear of big brother’s all seeing pineal eye this has not been the case (further discussion to follow).
Image 7: Depiction of Facial Geometry Biometric
Source: http://www.safe-travel.com/spids/v3/images/tech_pic1.jpg
Facial Thermography
Employs the use of an infrared camera to capture the emission of heat patterns that are generated by the vascular system of the face. Heat that passes through facial tissue of a human being produce a unique and repeatable pattern (aura). The captured aura is converted into data and then compared to stored auras of authorized individuals, at which point possible matches are generate along with probability percentages. The facial print does not change over time and is accurate than facial geometry identification technologies.
Image 8: Depiction of Facial Thermography Pattern Biometric
Source: www.msu.edu
Iris Scan Recognition
The iris (colored portion of eye) is a protected internal organ of the eye, behind the cornea and the aqueous humor, yet readily visible externally at a comfortable distance. The iris is composed of elastic connective tissue, with traceable meshwork, whose prenatal morphogenesis is completed by the 8th month of pregnancy. It consists of pectinate ligaments adhering into a tangled mesh revealing striations, ciliary processes, crypts, rings, furrows, a corona, sometimes freckles, vasculature, and other features. During the first year of life a blanket of chromatophore cells usually changes the coloration of the iris, but the available clinical evidence indicates that the trabecular pattern itself is stable throughout the lifespan (Daugman, n.d.).
Image 9: Depiction of Iris Scan Biometric
Source: http://www.cnn.com/2000/TECH/computing/07/24/
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The original concept was developed by Dr. Leonard Flom and Dr. Aran Safir, and the original software patents were developed by Dr. John Daugman. IriScan, Inc. acquired the patent rights from Dr. Daugman and licensed the rights for banking and government kiosk applications to Sensar, Inc. While both Sensar and IriScan use the same underlying technology, Sensar has enhanced the acquisition process.
Being that the iris is an internal organ of the eye, the iris is immune (unlike fingerprints) to environmental influences, except for its pupillary response to light. Pupillary motions, even in the absence of changes in illumination, and the associated elastic deformations it creates in the iris texture, provide one test against photographs, glass eyes, or other resemblance of a living iris. Other tests involve changing infrared LED light sources which should cause corresponding changes in their specular reflections from the cornea; detecting the properties of contact lens which might contain a printed fake iris pattern riding upon the spherical surface of the cornea, rather than in an internal plane within the eye; testing for the properties of living tissue under varying wavelengths of both visible and infrared illumination; and so forth.
Image 10: Left eye of researcher (Dr. William Lawson)
Left Eye Before Lasik Procedure Left Eye After Lasik Procedure
However, with the advent of laser procedures such has LASIK to correct myopia. It is now possible to reshape of the corena, thereby altering the keratometic (refractive) values and thickness of the eye. While laser procedures do not alter the iris itself, it does alter the cornea and that alone may be enough to provoke a FTA (Failure to Acquire) or a FR (False Reject) error in the matching process. Above is an attempt to demonstrate the effects of Lasik, the subject is William Lawson (Courtesy of Lasik Plus).
Retina Scan Recognition
The retina is the surface inside the back of the eye, upon which images that have passed through the pupil are focused. In order to use a retinal scanner, the user places her eye relatively close (between 1 and 2 inches) to the reader and focuses on a rotating green light. In order to enroll, five scans of good quality are recommended; to verify, a single scan is needed. This technology is generally used for physical security applications rather than for data security applications.
Despite its relative sophistication, retina scan is actually one of the oldest biometrics. As far back as the 1930's, research suggested that the patterns of blood vessels on the back of the human eye were unique from person to person. With the exception of some types of degenerative eye diseases, or cases of severe head trauma, retinal patterns are stable enough to be used throughout one's life.
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