2000-12-21 – Personal privacy areas

As we enter the third millennium, personal data security and privacy
become goals that are ever harder to achieve. You may have read about the ‘flash
hat’ which renders flash photography of a subject impossible. How, then, to
perform the same feat with a video camera? Suppose that you used infrared floods
and spots to shine both onto the subject and away from the subject. The infrared
would upset any black and white cameras attempting to take your photo, colour
video cameras using an infrared system for range finding would also be put out,
light meters and auto white balance may also suffer. The infrared shining onto
the face would also cause areas of over exposure and under exposure on an
infrared or black and white camera, or night sights.

A similar system could be used to ensure privacy against audio bugs and/or
parabolic microphones. A suitable arrangement would be several relatively
directional sound sources connected to a computer playing pink noise with a
spectral frequency similar to the ‘subjects’. The computer is used to advance
and retard the delay on each of these speakers in order to effectively cancel
the obscuring pink noise in the ears of the subject. This may require ear plugs,
however if not, no system outside the perimeter of speakers (and sound) would be
capable of determining what was being said inside. Laser eavesdroppers and human
ears would probably be the only systems that could overcome this, and let’s not
forget lip readers.

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