Slashdot Mirror
Paint Provides Network Protection
thefickler writes "Forget WEP and WPA; I'm switching over to the EM-SEC Coating System, a recently announced paint developed by EM-SEC Technologies that acts as an electromagnetic fortress, allowing a wireless network to be contained within painted walls without fear of someone tapping in or hacking wireless networks. The EM-SEC Coating System is clearly the most secure option aside from stringing out the CAT5, and can be safely used to protect wireless networks in business and government facilities."
The idea of containing electrostatic and electromagnetic fields is to create a Faraday cage. If you are within an unbroken metal shell, most alternating fields and all electrostatic fields can't reach you. Un-alternating magnetic fields can still pass through. The problem is that any break in the metal shell is a possible window for the fields. That means the shielding on the walls has to be completely bonded to the shielding on the ceiling and floor and windows. The doors use something akin to weather stripping.
The other problem is that wires pass through the faraday shield in most cases and those provide a path through it. The bottom line is that if you are relying on a coat of paint to protect you, you're going to be sorely disappointed.
Theoretically you would have a doubled doored vestibule... Most commercial buildings have one anyway to keep the (heat|air conditioning) bills low.
A physical barrier is not security through obscurity.
Assembling etherkillers for fun an profit
> Remember, radio signal strength is logarithmic.
No it isn't. It is inversely proportional to distance squared.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
Cell phones are all lower frequency
From 800 MHz to 1.9 GHz
(and something about 450MHz, but that isn't common)
Don't you think they can limit their product to 2.4 GHz +/- 500 MHz?
[Fuck Beta]
o0t!
http://www.rustoleum.com/product.asp?frm_product_i d=644&SBL=1
painted my daughters room with it OVER 3 YEARS AGO and it does the exact same thing. we lost cellphone coverage in that room (aluminum screens and storm windows complete the circuit)
The overpriced paint mentioned in that article and I have see elsewhere for the tinfoil-hat crowd is no better than the el-cheapo rustoleium primer applied as 3 coats so that fridge magnets happily adhere to the wall.
Do not look at laser with remaining good eye.
When you talk about grounding the walls and floors and ceilings, you have also to talk about how you are going to do the grounding. Any conductor that you use will act like an antenna or at least it will have significant impedance. Really, the only way to do a Faraday cage is to have an unbroken metal shell. Your comment about wavelength is correct; again as far as it goes. For instance, the window of a microwave oven consists of a bunch of holes which are too small for the RF to squeeze through. On the other hand the gap can be long and narrow so the shield on the wall and the shield on the floor won't work if they aren't bonded every inch or so at the frequencies you mention.
I take note that the grandparent is modded as a troll. Somebody should have to explain that one. I'm guessing that whoever modded it that way would have trouble with Ohm's law let alone RF circuits.
Is lead the only metal that
1) Can be made into a paint
2) Conducts radio waves (this is a Faraday Cage for radio waves)?
The answer is no. Most metals conduct radio waves to some degree, just like most can conduct all EM radiation. There are quite a number to choose from that are harmless to humans. Lead is the big choice because its so dense, but we're not talking about nuclear radiation here (and more importantly, we're not talking about nuclear particles, which are stopped by other matter getting in the way, not just by conductive materials). We're not blocking the EM equivalent of a truck - just a series of tubes.
I can see a way around the window/door thing as well.
Put enough conductive material into the Windows and you'll get the same effect. In addition, there are some shapes you can make the entryways (again using principals of a Faraday cage) that will cause the radio waves to tend not to reflect out.
Mod me down and I will become more powerful than you can possibly imagine!
Called "selective screens". Used everywhere here in Finland. They let heat in but not out. However, they are not of any use for blocking radio signals. (I guess they are also used in other parts of the world for the opposite effect)
Bot Assisted Blogging
I remember reading about it from a luddite *keep the emf out* website
A quick google reveals this
There's no doubt more.
It's illegal to actively block frequencies (by using a jammer, for instance), but not illegal to passively block frequencies (by creating a Faraday cage, like this paint is trying to do).