By Joseph Moran

Most of us gain access to our computers (and lots of other stuff, too) by typing in a password or PIN. In the future, this will go by the wayside as we rely more and more on biometric forms of authentication, which work by measuring and analyzing characteristics of the body such as fingerprints, voice or a face.

I recently came across LemonScreen, an interesting utility that works with a webcam and lets you log into your Windows system using your face in lieu of a typed password. Although it’s currently a bit rough around the edges and it does have some major limitations, LemonScreen is still pretty cool to try and it offers a taste of biometrics at home.

You can download LemonScreen directly from Key Lemon. The software is freeware, and like just about everything these days, in beta. Although the download link references compatibility only with Windows XP, I successfully used it on a Vista system as well. According to the site FAQ, a Mac OS X version is under development, as is an update to the Windows version.

Once LemonScreen is installed on your system, launch it and click the Settings button. One of LemonScreen’s limitations is that it uses its own session-locking mechanism and inactivity timer rather than the one built into Windows, so here you must specify how long you want the system to be idle before LemonScreen locks your session. You should also make sure your webcam is listed next to Camera device.

LemonScreen should be compatible with most relatively recent USB-based cameras — I used a couple of Logitech QuickCam models.

Now it’s time to “register” your face with the software, so click the Enrollment button. You should see the live webcam feed with a flashing red box attempting to detect your face in the image. First, type your Windows account password into the box provided (you don’t have to hit Enter); then, move the mouse cursor over the Update model button, but don’t click it. Finally, position your face in the window until the two vertical indicators on the right are showing green, then click the Update model button. It will take several seconds to create the model. When it’s finished, click save to minimize LemonScreen to the Windows tray. Not surprisingly, it’s the one that looks like a face.

When the system has been idle for the specified amount of time, LemonScreen will kick in and present the webcam window centered within a white screen. By default, the live webcam image is displayed for five minutes and then it goes dark. You can reactivate it by moving the mouse or changing the timeout from the Settings menu. To log back into your computer, look into the camera from no more than a foot or two away; the red face detection box will appear. When the software recognizes you, you’ll regain access to the system. If something goes wrong, you always have the option of logging back in using your standard Windows password.

Facial recognition doesn’t work by simply snapping a picture and using it as a comparison, but rather by storing a mathematical analysis of your facial dimensions, which are static and unique to you. Although I wore glasses when I created my facial model, LemonScreen recognized me even when I wasn’t wearing them. When I tried doing things like having someone else look into the camera for me or holding a picture of myself up to the lens, LemonScreen didn’t get tripped up. However, some people in the online forum claim to have been able to fool the software with such tactics.

To have LemonScreen lock your system manually without waiting for the inactivity period, select that option from the tray icon or pressing ALT+L. Remember, LemonScreen doesn’t tie into Windows login, so if you lock your system with the standard Windows Logo+L or it locks due to Windows screen saver settings, you’ll need to log back in the conventional way.

For this reason, you can’t use LemonScreen for your initial login at system startup.

Right now, the LemonScreen experience is both sour and sweet (sorry, couldn’t resist). Think of it as a fun thing to play with more than a serious security tool. Hopefully, the next update will better integrate with Windows. In the meantime, check out LemonScreen if you’re looking for a cool and convenient way to access your system with your face instead of your fingers.

Joseph Moran is a regular contributor to PracticallyNetworked.