HOW DOES IT WORK?
The principle behind Van Eck phreaking is pretty simple. Your computer monitor, as well as your keyboard and mouse, emit a high-frequency radio signal. If you’re old enough, you’ve seen that signal in action. Remember when your mom used to scramble the television by firing up the blender for another round of margaritas? Van Eck radiation in action!
With a portable monitor (to see what there is to see), a variable oscillator and frequency divider (to let you filter and synchronize incoming signals), an antenna (to capture the signals), and the proper cabling, you can intercept the signals output by pretty much any modern electronic device. Wonder what your neighbor is laughing so hard at on the television? Phreak the signal and find out. Curious about why the woman in the cubicle next door needs to hit her keyboard so hard? Your trusty Van Eck interceptor can recreate those violent keystrokes.
Federal Communication Commission standards require modern electronics to include a small amount of shielding, simply to prevent the interference people in their thirties remember from their childhood. What shielding is there, however, is not enough to prevent eavesdropping.