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Using Aluminum Oxide Paint To Secure Wi-Fi
eldavojohn writes "The BBC reports on people using aluminum oxide in their paint to block Wi-Fi signals from leaving their home or business. Aluminum oxide resonates at the same frequency as Wi-Fi signals and other radio waves, blocking data from going outside a building. It's not a flawless solution, as it may also block AM/FM signals. You or your neighbors may be unwittingly using this already, as most pre-finished wood flooring uses aluminum oxide as a protective coating."
Wouldn't keeping radio signals in also have the unfortunately side effect of keeping radio signals out? While having a neighborhood coffee shop offer free wifi to paying customers while being an of oasis of cellphone-free peace & quiet would be sweet, having no cellphone reception at home because one desperately wants to prevent neighbors from stealing one's wifi seems very inconvenient (especially when setting up even the most basic built-in wireless router security would successfully do the trick in 99.9% of cases).
Just once I'd like someone to call me 'Sir' without adding 'You're making a scene.'
I'm already using aluminum foil lining in many of my hats and clothes to protect me from the government transmissions. However, I hadn't heard that Al2O3 was any better than straight aluminum foil.
It seems suspicious that this story would be posted immediately after I began considering papering my walls with foil.
...a way to stop wearing this itchy tinfoil hat!
Then != than you morons.
Wouldn't you have to paint over the windows?
I dipped my head in this aluminum oxide paint, and it keeps all their signals out. Granted, I look somewhat like a cyborg now, but this stuff should work just fine for an office trying to keep their signals in.
Authority questions you. Return the favor.
Note, the material concerned is Aluminium IRON oxide. Big difference. Aluminium oxide is a good dielectric and would be bugger all use for RF shielding. Oh and the article is a wierd too: it talks about 100GHz shielding where WiFi bands are ~ 2.5GHz.
Dunno where they got the crap about "resonates".
The paint might act as an electrostatic shield, or as a lossy dielectric, both effects that will attenuate RF signals.
But resonate, no.
We do know the world would be a better place if everyone shared their wi-fi securely using
a technology like FON, don't we. (No I'm not associated with the company. Just recognize a
great concept when I see one.)
I'm seriously tired of how, particularly in the US, sharing wi-fi gets implanted in peoples'
brains as a criminal, borderline terrorist activity, with terms such as
"theft of tele-communication resources" and similar Orwellian mindf**k terms.
Where are we going and why are we in a handbasket?
> What frequencies are not resonant in Aouminum Oxide paint?
The reporter is just yammering. He hasn't the foggiest idea what the word "resonant" means and knows less than nothing about radio. All we can glean from this is that someone has put out a press release about rf absorbant paint, something that has been around for decades.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
You select WPA2-PSK in your router's config, press "generate key", make a note of the generated key, connect your laptop to the encrypted WLAN, enter the key, done. No beacon disabling, radio frequency shielding, MAC filtering, DHCP disabling or other nonsense necessary. It's like people are trying to test every option but the right one.
Using information in the article I was able to find the actual science paper. It turns out they are able to tune the resonate frequency of this paint. Very cool. However, the it doesn't go all the way down to 2.4 GHz. That's a pretty long wavelength for this process.
Where I am there is some WIFI (hidden or not) on every channel. There are large broadcast towers about half a mile from me which have various Internet over 802.11B from service providers.
My WIFI in my home has a hard time with all this. This paint would be a good way for me to improve my in home signal. A lot of my equipment doesn't support the new 5Ghz of 802.11N, so while I have 802.11N APs they do not help much.
The number of times I've "borrowed" wi-fi from a neighbour, I felt obliged to leave mine open for everyone to use.
:)
I did however install the Tomato firmware on my router, and use it's brilliant QoS to limit all machines but my own to 56k connections
I happen to live in Minnesota, where most homes have basements. Our Comcast cable enters the house through the basement, so I figured it was a convenient place to hook up the WiFi access point. The WAP is sitting on the bottom shelf of a bookshelf I have there.
The net effect is that I have great WiFi signal throughout the house. I have a wood frame house, and WiFi signal is not retarded by normal wood construction. However, I get almost no signal as soon as I step out the back door onto the porch. A few feet away from the house, I can't pick up the signal at all. I've also tested it from the street, and it's like my WAP isn't even there. No, I'm not using any special paints or "Faraday cage" wallpaper.
That's because basements are constructed from cement blocks, which do a pretty good job of retarding WiFi signal. Not to mention my basement is 6-7 feet underground (there are windows at almost ceiling height) and all that dirt also helps block the signal. I figure I'm pretty safe from snooping. Sometimes it helps to just be incrementally harder to get to than the next guy. If you're a wardriver who's interested in free WiFi, my neighbor two doors down is an easier target (his WAP is on the second floor of his house, so he's essentially broadcasting to the whole neighborhood.) Or I suppose you could drive down a block and a half to the coffee shop who runs a completely open WAP.
* And yes, I do use good WAP security, with encryption, long passphrase, MAC filtering, only wired connections are allowed to connect to the admin screen.
the aluminum siding does a great job of keeping wifi in my house. i can hardly get a signal in my yard without LOS to the router through my window.
:(
after installing a steel garage door, it did a pretty effective job of preventing my garage door opener from working either
I checked my deo, but no aluminum so I googled around and apparently it's an ingredient in antiperspirant which is in some deodorants (mine's the plain kind). Interestingly this turned up some debate on the safety of aluminum use :
"A small study in 17 women with breast cancer was quite widely reported in the news in 2007. It found higher levels of aluminium in the part of the breast nearest the skin, and the authors speculated that aluminium in deodorants might cause breast cancer. But the design of this study was not strong enough to draw that conclusion." From cancerresearchuk
And from wikipedia : "Aluminium, present most often in antiperspirants, but not usually present in non-antiperspirant deodorants, has been established as a neurotoxin in very high doses."
From what I can tell smearing it on your skin is probably OK and ingesting it in more than trace amounts should probably be discouraged :-) Thanks for the tip.
If all else fails, immortality can always be assured by spectacular error.