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Wireless Security By The Gallon
prostoalex writes "The next effort to improve wireless security might involve a trip to Home Depot. Force Field Wireless sells buckets of aluminum and copped-laced paint designed to prevent the 802.11 packets from escaping the building, Information Week reports. The article also talks about the Firce Field's pitch to the government in order to improve the homeland security, but the only governments that got interested in anti-Wi-Fi paint were from the Middle East. According to the products page, they also sell the brush sets." Easier than wallpaper, or moving into an old house.
Q. Does it really work?
A. Yes, to some extent. The metalic paint does effectively impede radio signals however, it is not 100% effective. Some signal may still leak through the paint also, untreated windows and doors will allow the signal to leak. None the less, signal propagation is greatly reduced by the paint, which was the primary reason for its development.
Q. What about cordless phones?
A. This paint will affect most radio signals including corless and cell phones, AM/FM radio, broadcast TV and more. The overall effect will vary depending on paint application quality, signal frequency and strength, as well as other factors.
Q. Is this paint a health risk?
A. Copper based paint, commonly used in marine applications, is a known health risk and environmental hazard. While there is little data available for aluminum based paints, there do not appear to be significant health risks at this time. This does not mean that there aren't health risks associated with aluminum based paints.
TEMPEST is the codename for a pseudo-mythical method of surveillance used to intercept data from electrical devices, such as your computer, by intercepting unintended EM emanations. To quote:
"TEMPEST was "invented" in 1918 when Herbert Yardley and his staff of the Black Chamber were engaged by the U.S. Army to develop methods to detect, intercept, and exploit combat telephones and covert radio transmitters. The initial research identified that "normal unmodified equipment" was allowing classified information to be passed to the enemy through a variety of technical weaknesses. A classified program was then created to develop methods to suppress these "compromising emanations". However, the actual acronym known as TEMPEST was only coined in the late 60's and early 70's (and is now considered an obsolete term, which has since, been replaced by the phrase "Emissions Security" or EMSEC).
TEMPEST and it's associated disciplines involve designing circuits to minimize the amount of "compromising emanations" and to apply appropriate shielding, grounding, and bonding. These disciplines also include methods of radiation screening, alarms, isolation circuits/devices, and similar areas of equipment engineering.
TEMPEST disciplines typically involve eliminating or reducing the transients caused by a communication signal and the resulting harmonics. These signals and their harmonics could allow the original signal to be reconstructed and analyzed."
Link:
http://www.tscm.com/TSCM101tempest.html
The idea is that EM fields generated my, say, your monitor can be intercepted and used to reconstruct what's being displayed on the screen.
It's not the paster or stucco, but the metal lath to which the stucco and plaster are adhered to.
If you ever see it installed, they (usually) first staple up a thick metal mesh, which holds the plaster in place. Wood lath was the status quo in the really olden days, before steel became cheaper than hardwood strips.
Norm Abrahms goes wardriving in this weeks episode of This Old House!
I don't need no instructions to know how to rock!!!!
The Defend Air people don't give any data I can find on the dB-vs-MHz effectiveness of their product, but plenty of competitive technologies do. I wish they did, because I want to line my laundry room with the stuff! The washing machine makes a terrible racket in my radio.
...and their own copper paint which is startlingly more expensive than the DefendAir product...they even have the same window film that keeps out the sun, but also makes your cell phone not work.
There's Hospital Quality shielding done with aluminum foil, and more serious shielding of both E and H fields for MRI machines. I won't even go into the RF-sealed doors...
If you're concerned about magnetic fields, then Mu Metal is the stuff. Just don't bend any of the Hydrogen-annealed variety. You can get sheet and tape in small quantifies from these folks, who by the way also offer "Personal Protection Devices (silver-impregnated fiber baseball caps, not tinfoil hats, please)
For sealing over the gaps, don't forget 3M 1181 Copper Tape, which features electrically-conducting adhesive, but only specifies 80dB isolation at 30MHz-1GHz.
But my favorite so far is Metal Foam, which reminds me of the almost weightless foamed glass Aerogel that was a announced a few years ago... Foamed aluminum is available commercially in 2x2ft sheets from from Austria, Alulight. They claim 40dB isolation in the 2Ghz range and over 100dB to 140dB in the 10Mhz-1GHz range, plus excellent sound isolation, structural, and fire safety properties. What's not to like? Anybody know where the get this stuff in the US? Reade seems out of my range, but I'll ask them.