What do you get when you add aluminum iron oxide to regular latex housepaint?

If you follow the recipe developed recently by researchers at the University of Tokyo, you get an effective barrier for radio signals that could effectively lock drive-by WiFi freeloaders out of your home or small office wireless network.

According to the inventors, the additives in their paint resonate at the same radio frequencies used by wireless systems, effectively blocking connections from outside of any building coated with the compound.

The researchers didn’t say how much more the WiFi shield paint might cost than regular exterior finishes but at least one paint expert of our acquaintance speculates that that users would not only have to pay significantly more for the paint but also buy more if it, perhaps enough to apply several coats, to ensure an effective WiFi barrier. And the effectiveness of the barrier would also depend, to some degree, on the skill of the painters — specifically, their ability to apply even, consistent coats.

One way or the other, industry observers say it would be just a matter of time until freeloading hackers found a way aroud the barrier. Whether the new WiFI barrier paint ever hits the shelves as a product remains to be seen.