From there, it is compared against other such images in a database and then either authorized or (in some cases) stored as unauthorized access. This method is faulty, however, due to the fact that sometimes the image isn't scanned correctly or is blurry or unfocused. In this situation, the scanner would more than likely re-scan the image and continue from there. Capacitance scanners create an image of a finger as well, but in a different way. Instead of sensing light, an image is created based on current received from a large array of tiny conductor plates (by tiny I mean smaller than the ridges and valleys in your fingers). For an adequate representation of such cells:.
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As shown, current is produced by a ridge on the finger, and each point is mapped out by the current produced and from there is converted into an electrical mapping of a fingerprint. This system is more difficult to trick, due to the fact that scanning is based on electrical currents and not an actual picture. The actual analysis of fingerprint image relies on specific points of the print, as opposed to an entire comparative analysis (this takes increased processing power and presents another security flaw). Most systems compare what is known as minutiae: specific features of the fingerprint; as well as bifurcations: where a ridge line ends or where one ridge splits into two. From there, the scanner software uses algorithms to analyze these features. A commonly known flaw in such systems, namely in optical scanners, is the use of gummy bears to spoof the image of a fingerprint by smashing it onto the scanner, picking up the oil left by a previous fingerprint and usually capturing the minutiae necessary to bypass the system. .
Retina Scanning.
Retina scanners are the next most commonly used biometric systems, and possibly the most difficult (if not impossible) to bypass. Retinal scanning essentially makes a map of blood vessels in the back of the eye, using a low-intensity light.
