- A bio-metric identifier known as a retinal scan is used to map the unique patterns of a person's retina
- uses the unique patterns on a person's retina to identify them
- The pattern of variations is converted to computer code and stored in a database.
- retinal patterns may be altered in cases of diabetes, glaucoma or retinal degenerative disorders
- the retina typically remains unchanged from birth until death
Authentication is the process of
verifying that a person is indeed who they claim to be.
Biometric authentication refers to
using a physiological characteristic to perform that verification. Biometrics
offer some security advantages over other authentication methods, for example
an eye cannot be stolen like a key card or forgotten like a PIN or a password,
and biometrics cannot be shared between individuals. At the time of enrollment,
documents or other means are used to identify the individual, and the biometric
measure is captured and stored for future comparison.
We forget our highly secretive combinations, so we frequently have them reset and sent to our cellphones and alternative email addresses. We come up with clever jumbles of letters and words, only to mess up the order. We sit there on the login screen, desperately punching in a code we should know by heart.
We forget our highly secretive combinations, so we frequently have them reset and sent to our cellphones and alternative email addresses. We come up with clever jumbles of letters and words, only to mess up the order. We sit there on the login screen, desperately punching in a code we should know by heart.
A biometric identifier
known as a retinal scan is used to map the unique patterns of a
person's retina.
The idea for retinal identification
was first conceived by Dr. Carleton Simon and
Dr. Isadore Goldstein
A retinal scan, commonly
confused with the more appropriately named "iris scanner", is a biometric technique
that uses the unique patterns on a person's retina to identify
them. The biometric use of this scan is used to examine the pattern of blood
vessels at the back of the eye.
The blood vessels within
the retina absorb light
more readily than the surrounding tissue and are easily identified with
appropriate lighting. A retinal scan is performed by casting an unperceived
beam of low-energy infrared light into
a person’s eye as they look through the scanner's eyepiece. This beam of light
traces a standardized path on the retina. Because retinal blood vessels are
more absorbent of this light than the rest of the eye, the amount of reflection
varies during the scan. The pattern of variations is converted to computer code
and stored in a database.
Retinal Scan technology maps the
capillary pattern of the retina, a thin (1/50th
inch) nerve on the back of the eye. To enroll,
a minimum of five scans is
required, which takes 45 seconds. The
subject must keep his head and eye
motionless within ½” of the device,
focusing on a small rotating point of green
light. 320 – 400 points of reference
are captured and stored in a 35-byte field,
ensuring the measure is accurate with
a negligible false rejection rate
Eyeglasses and contact lenses present
no problems to the quality of the image,
and the system further tests for a
live eye rather than, say, a lens with an image
printed on it, by checking for the
normal continuous fluctuation in pupil size.
The human retina is a
thin tissue composed
of neural cells that is
located in the posterior portion of the eye. Because of the
complex structure of the capillaries that
supply the retina with blood,
each person's retina is unique. The network of blood vessels in the
retina is not entirely genetically determined and thus even identical twins do
not share a similar pattern.
Although retinal patterns may be
altered in cases of diabetes, glaucoma or retinal
degenerative disorders, the retina typically remains unchanged from birth until
death. Due to its unique and unchanging nature, the retina appears to be the
most precise and reliable biometric, aside from DNA. Advocates of retinal
scanning have concluded that it is so accurate that its error rate is estimated
to be only one in a million.
Retinal scanners are typically used
for authentication and identification purposes. Retinal scanning has been
utilized by several government agencies including the FBI, CIA,
and NASA
Advantages
Low occurrence of false positives
Extremely low (almost 0%) false
negative rates
Highly reliable because no two people
have the same retinal pattern
Speedy results: Identity of the
subject is verified very quickly
Disadvantages
Measurement accuracy can be affected
by a disease such as cataracts
Measurement accuracy can also be
affected by severe astigmatism
Scanning procedure is perceived by
some as invasive
Not very user friendly
Subject being scanned must be close
to the camera optics
High equipment cost
Refrences:
