In one of my previous blogs on "The six dumbest ways to secure a wireless LAN", I struck a cord with my readers like never before. I'm still laughing over the fact that of all the wireless articles I've written over the years on how to secure your wireless LAN, I finally get around to write an article on how NOT to secure your wireless LAN and it gets the best responses. It was a great feeling getting all the emails and feedback thanking me and that they were running real wireless LAN security now.
In one of the funnier responses by reader Kenetrix, Kenetrix tells me that I may have missed a myth on my wireless LAN security hall of shame. Apparently, one of his customers in what he describes as a "betcha-ya-didn't-know-about-this-one" way asked him "what about this special paint that can prevent wireless signals from leaving the building". Um, I hate to break this to you Kenetrix, but there really is such a thing so I hope you didn't laugh in his face when he told it to you :). The one saving grace for you is that the paint isn't 100% full proof because there is still some leakage and can still be picked up by a high powered antenna. Essentially, this pretty much falls under myth #5 in my original myth blog "antenna placement". It does reduce the problem, but it's not completely effective. Even if it were 100% effective, buying a brand new Router/Access Point for $80 that supports AES encryption and a new client adapter for about $70 that supports AES encryption is a lot cheaper than repainting the house and buying special glass film for your windows.
Additionally, there is also a special wall paper developed by BAE Systems that promises to work better and even allow other frequencies through while specifically blocking Wi-Fi frequencies. This way, the radios and cell phones can keep working while 2.4 GHz is being blocked. Note that this is not a commercial product yet.
The bottom line is, even if there is a paint or wall paper that does block 100% of all Wi-Fi signals, we must keep in mind that they offer no protection from hacking inside a house or office. There is simply no substitute for good authentication and good encryption any time you care about your privacy and security. Where this technology will have its niche is cases where there is an extremely high density of Wi-Fi users. For example, a school may have 20 students per room all using Wi-Fi and they don't want to adjacent rooms to interfere with each other. This might also work for neighbors who are spectrum hogs.