It may seem silly to say that "the future is now" but it is absolutely true.

As far-fetched as movies like seem, there is always a grain of truth to be gleaned from them.

Such is the case in futuristic movies like Minority Report where people drive hover cars and stealing other's eyeballs in order to infiltrate buildings. While hover cars are still things of the future, the fingerprint scanners in the movies are not fictitious.

The fingerprint scanner is a biometric device which can control access—to rooms, computers or other storage—by reading certain characteristics with a biometric sensor. In the case of an fingerprint scanner, it's the fingerprints; however, biometric locks also scan traits such as facial structure, eyes and voice.

After the sensor creates an input image, it compares it to a database of enrolled (permitted) users to make a match. If your fingerprint or face is in the system, you're in!

Different sensors produce different images, such as 2D and 3D sensors. 2D sensors produce flat or two dimensional images as is the case with fingerprint.

The images captured by a 2D sensor indicate only one facet of the subject (the underside of the finger), without taking into consideration how the finger is represented in space.

Although fingerprints are unique, a 3D sensor gives a more detailed image.

Additionally, 2D facial scanners could fail to authenticate your identity if your face is at a different angle or if you have an expression which differs from the one which is stored in the memory of the device while 3D sensors are less susceptible to these issues.

For these reasons 3D sensors are becoming increasingly popular.

Many 3D sensors use structured light in the form of an LCD projector or laser bar to compile a three dimensional image of the subject.

One benefit of 3D sensors is that they simultaneously scan multiple points, unlike other 3D scanning methods.

In biometrics, 3D devices focus on unique physical characteristics. For example, studies suggest that your ear has a shape as unique as your fingerprint which can be used to identify you. 3D facial scans are also common and may prove to be more accurate than 2D facial scans.

Generally, 3D biometric sensors are less available than 2D sensors and there are not as many standardized specifications from which to compare 3D sensors, because this technology is still in development.

Two and three dimensional sensor technologies are often combined for systems which recognize both 2D and 3D imagery.

This is the case with a European bank which, in 2006, added a facial recognition to increase security. However, there are not many, off-the-shelf alternatives available.

When shopping for a biometric lock, whether it is 2D or 3D, pay attention to certain specifications:

• Dots Per Inch (DPI)—indicates image resolution; look for a DPI of 400 or more

• False Acceptance Ratio (FAR)—the likelihood of a match being made incorrectly

• False Rejection Ratio (FRR)—the likelihood of a true match being rejected

In the future we will likely see an increase in the use of 3D biometric technology. However, 2D sensors tend to be sufficient for current use.