Biometrics

Many new biometrics products are becoming available to the public today, most of which use fingerprint matching for verification or authorization. Such fingerprint matching products include door locks, computer access locks, and safes. When questioning the security of these biometrics products, many wonder how the fingerprint matching is accomplished, and how hard it is to fake a match.

There are two methods of fingerprint matching: graph based and minutiae based. Graph based fingerprint matching uses the whole image of the fingerprint to attempt to make a match. Minutiae based fingerprint matching uses specific points of the fingerprint that are unique when combined to make a match. The minutiae based fingerprint matching method is most commonly used in biometrics products today.

There are two major reasons minutiae based fingerprint matching is used for biometrics products. First, minutia based fingerprint matching takes up less space in the small computer like memory that stores fingerprints in the biometrics products. When a graph based fingerprint matching method is used, the entire print must be stored as an image in the computer memory. However, when minutiae based fingerprint matching method is used, the key points of the fingerprint, or the minutiae, are stored as numerical data, which takes up much less space in the computer memory.

The other reason that minutiae based fingerprint matching is used for most biometrics products is that minutia based fingerprint matching is more secure and accurate. You see, an image can be skewed, not allowing for a perfect match to come up. But minutia based fingerprint methods require that a large percentage of the points must match the newly scanned print in order for access or authorization to be given. The percentage of points that must be identical in order to establish a match is called the threshold. This method is how forensic scientists match fingerprints between crime scenes and databases.

Unfortunately, criminals are always one step behind, or in some cases one step ahead, of technology. There are a few ways that fingerprint matching scanners can be fooled into allowing access to those to whom access should be denied. Whether or not this is an issue with the biometrics product depends on what type of scanner is used to obtain the fingerprint for matching.

There are two types of fingerprint scanners. One uses light to "copy" the fingerprint, then make a match with a fingerprint in the system. This type of technology is the same technology used in digital cameras and video recorders. The other type of fingerprint scanner uses electrical currents to pull the fingerprint image from your finger and attempt to make a match with another fingerprint in the system.

If you have a fingerprint scanner that uses electrical currents to pull the image, you will likely be much safer and more secure using the biometric products. However, the light fingerprint scanners are very easy to fool. There are two main methods that these fingerprint scanners can be fooled. One way is for a fingerprint to be taken from the scanner itself or from another object. The fingerprint is then transferred to a gelatin mold, which, when held against the finger and then scanner can resemble the fingerprint in memory.