Putting Your Finger On the Pulse of Access Control

When biometrics was introduced to the security industry, people scoffed at the idea of using parts of their bodies to gain access to a secured area. They had concerns about their voices being analyzed, their hands being radiated and their eyes being damaged by 'lasers.'

Voice recognition, hand geometry, and iris scanning all eventually moved into the role of acceptable means of identification for the security professional. The exception to the biometric scare was fingerprints. People have had their fingerprints recorded since birth.

Among all the biometric techniques, fingerprint-based identification is the oldest method. It has been successfully used in a variety of law enforcement and security applications. Large volumes of fingerprints are collected and stored everyday in applications including forensics, access control, and driver license registration. An automatic recognition of people based on fingerprints requires that the input fingerprint be matched with a large number of fingerprints in a database (FBI database contains approximately 70 million fingerprints!).

Professionals have come to the conclusion that everyone has unique, identifiable fingerprints. A fingerprint is made of a series of ridges and valleys on the outermost layer of skin of the finger. The pattern of ridges and valleys, as well as a variety of intersecting and ending points, determines the uniqueness of a fingerprint.

Fingerprint readers use algorithms as a method to identify and categorize. An algorithm is described as a step-by-step problem-solving procedure, especially an established, recursive computational procedure for solving a problem in a finite number of steps. To reduce the search time and computational complexity, it is desirable to classify these fingerprints in an accurate and consistent manner so that the input fingerprint is required to be matched only with a subset of the fingerprints in the database.

To map an entire fingerprint is time-consuming; even the most expensive equipment can take one or more minutes. Once the fingerprint is mapped, it must be compared to the database of fingerprints. This takes even more time. This is a significant amount of time when reading a fingerprint is used to control access.

For this reason, fingerprinting equipment manufacturers are constantly investigating methods to pool evidence from various matching techniques to increase speed and overall accuracy of their systems. A commercial fingerprint-based authentication system requires a very low False Reject Rate (FRR) for a given False Accept Rate (FAR). This is difficult to achieve with any one technique. In a real application, the sensor, the acquisition system and the variation in performance of the system over time is very critical.

One method of sub-classification is to require another means of credential along with the fingerprint. By utilizing a pin number, proximity card or similar method, authorized users can be authenticated more quickly because only one fingerprint must be compared to the fingerprint wanting access.

Following are three examples of fingerprint use as a means of identification with different types of security products. We'll examine a fingerprint reader used as a switch, a standalone lock that uses a fingerprint instead of a keypad and a security case opened by a fingerprint reader. Each item is from a different manufacturer and the details are included to receive additional information.

BIOSCRYPT V-SERIES READERS

Bioscrypt Inc. offers a line of fingerprint readers that are used as controls for electric strikes, magnetic locks or almost any access control product. The V-Flex, V-Prox and V-Pass fingerprint readers are a convenient way to provide facility security and positive user identification. Each model is designed to augment existing security infrastructures such as proximity, magnetic stripe, keypad/PIN and barcode readers.