Monday, October 16, 2006

Defeating Face Recognition

Chicago is instituting a policy of cameras on every block. Well screw you, Mayor Daley. I don't want my life under the scrutiny of your corrupt and sinister thugs. While I may not be able to stop the cameras from going up, I can educate my fellow citizens on how to render them useless. It's just too bad that you're using my tax dollars to do this.

Cameras are part of one of Darpa's old projects .. HID technology, or "HumanId at a Distance". They advocate that it's used to pick known terrorists out of crowds in public spaces, but it's undoubtedly being used for more than that in our America of secret prisons and CIA-sponsored murders of American citizens.

Now keep in mind that most facial recognition systems require a reference photo to be cross-checked when the system scans your face. This would be something like a driver's license, credit card photo, or national ID photo. The technology basically renders your face into a computerized image of mapped "points" such as the dimensions of your chin, eyes, nose, etc. Then it translates those to numbers and does a quick search of all the numbers in its database (mapped to reference photos). It comes up with probability hits as to who you might be. It's suprisingly accurate when all the conditions are right (fresh photos, good lighting, etc.)

Methods for Foiling
Knowing now how it works, your next step is to use this knowledge to prevent it from reading your mapped points correctly.

1. Physically altering your appearance - This doesn't have to mean a big rubber Nixon mask. It can be as simple as mirrored sunglasses, wrapping a scarf around your face in cold weather, a bandage on the face, etc. These are relatively innocuous and won't attract a lot of attention. Additional countermeasures include wearing a mask or painting your face with stripes, but these I rule out as impractical when you're trying to avoid calling attention to yourself.

2. Altering the lighting - If the camera position is known, stay in shadow or turn your face away from it. Carry a cigarette or a cellphone and inconspicuously cover your face with your hand. A flashlight shined either at the camera or used to backlight your face also works, but will attract attention.

3. Good Prepartion - Many distinguishing marks occur in the reference photos and make it so that it's almost impossible to conceal your identity later on. Eyeglasses and facial hair play a prominent part in this. When posing for government photos, make sure you look as different in them as possible.

Some individuals have such a unique face that they simply are not able to avoid detection. Being alert to the presence of cameras and avoiding those locations is easy today, but will not be so by 2016 when almost all of the major cities are camera-promiscuous. In those situations it is necessary to inject as much noise in the system as possible. Move in large crowds, concealing yourself where possible behind other individuals. Use the landscape to your advantage. Don't walk through the normal 'channels' where public traffic is herded; instead take alternate routes in and out of public spaces.

Remember: Whether or not you use these methods today is up to you, but as a citizen it is your duty to know them. Our government is conceivably less benign today than it was in earlier years and is likely to continue its downhill slide under either party. Prepare for the future.