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Using Aluminum Oxide Paint To Secure Wi-Fi

Posted by Soulskill on from the prank-possibilities-abound dept.

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."

9 of 271 comments (clear)

  1. Extra protection? by BadAnalogyGuy · · Score: 5, Funny

    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.

  2. Note: AlFeO *not* Al2O3 by Anonymous Coward · · Score: 5, Informative

    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.

  3. Does not resonate with me by Ancient_Hacker · · Score: 5, Insightful

    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.

    1. Re:Does not resonate with me by _avs_007 · · Score: 5, Interesting

      Seriously... I work with a WiFi lab at work... I have a Faraday Cage in our lab... One of the techs forgot to install an optical isolator on the network cables, so for a few days the ethernet cables went right into the cage... Well, first day I went to use it, I locked myself in the cage, and was surprised that my cellphone started ringing... Without the optical isolators on the network cable, the RF signals were able to find there way into the faraday cage through the ethernet cables....

      with that being said, I highly doubt that simply painting your walls will keep RF signals at bay... Even when the grounding wire was simply loose on the door to the faraday cage, RF signals would leak in...

    2. Re:Does not resonate with me by quatin · · Score: 5, Funny

      So you went inside a Faraday Cage with an unprotected ethernet cable and managed to get cell phone reception. I on the other hand, can't get cell phone reception if I stand too close to my filing cabinet. I either need to switch to your provider or you need to come do your WiFi experiments next to my filing cabinet.

  4. Re:Resonance at other frequencies? by John+Hasler · · Score: 5, Informative

    > 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.
  5. Re:Cellphone reception? by morgan_greywolf · · Score: 5, Informative

    Try reading more carefully:

    FTFA:

    While paints blocking lower frequencies have been available for some time, Mr Ohkoshi's technology is the first to absorb frequencies transmitting at 100GHz (gigahertz). Signals carrying a larger amount of data - such as wireless internet - travel at a higher frequency than, for example, FM radio.

    ...

    "Our current mobile phones work at much lower frequencies, around 1.5 gigahertz. But, our material can also absorb frequencies that low, so you could block phone signals from outside and stop people's phones ringing during the movie," he said.

    From the sounds of it, just about anything below 100 GHz gets blocked. That means cellphones, too.

    --
    My blog
  6. What is so hard about using WPA2? by Anonymous Coward · · Score: 5, Insightful

    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.

  7. Re:Resonance at other frequencies? by Anonymous Coward · · Score: 5, Informative

    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.

    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.