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Wireless Networking Hardware Technology

RF-Blocking Wallpaper 344

spitefulcrow writes "Silicon.com is reporting on a new application for RF-absorbing materials: Wallpaper that blocks Wi-Fi. BAE, the British defense contractor, has announced that the same material used to foil radar by stealth bombers can be used to selectively block certain frequencies and prevent wireless networking signals from entering or exiting a building. Is this the next take on lining the walls with lead?"
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RF-Blocking Wallpaper

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  • by liamo ( 699840 ) on Sunday June 20, 2004 @06:01AM (#9477392)
    Tinfoil is just so passee these days.
    • Finally, I would prefer "wallpaper" underwear... In case all these RF are leading us to infertility, I would build a new branch of our societies!

      Remenber: always put your cell phone in your pant's pocket!

  • a new application for RF-absorbing materials: Wallpaper that blocks Wi-Fi.

    Ok, I know it's not tin foil....

    But the important question is, can I use it to make a hat [utexas.edu]?
    • by Fishstick ( 150821 ) on Sunday June 20, 2004 @06:40AM (#9477491) Journal
      Not nearly as effective or attractive as aluminum. ;-P

      Aluminum is the perfect medium for constructing an AFDB [zapatopi.net]
      1. Get a five foot sheet of aluminum foil (standard one foot wide Reynolds Wrap brand will do nicely.)
      2. Fold the sheet four times into five equal segments so that you end up with a 1x1 foot square, making sure that you fold over the dull side of the foil leaving the square shiny* on both sides.
      3. Use scissors to cut from one corner of the square to the center, making a straight line.
      4. Bend the foil from one side of the cut under the other, making a slight cone. Again, make sure that the outside of the cone has a shiny side of the foil; this is VERY important.
      5. Place the cone on your head and squash the top and sides to make it fit snugly.
      6. Apply Scotch tape liberally making sure to secure the cut in the foil and any form-fitting creases made in step 5.
      7. Use more tape to secure AFDB to your cranium.

      *A Note About The Shiny Side:
      It can't be stressed enough how important it is to have the shiny side pointing out. This is needed because the shiny side is most reflective to psychotronic radiation, while the dull side can actually, in certain environmental conditions, absorb it. However, as is illustrated in the instructions above, it is also wise to complement this with a layer of foil pointing shiny side in. This will keep your brain waves, which are also reflected by the shiny side, from being picked up by mind-reading equipment. There is a small number of aluminum foil researchers who believe that this may cause an alpha-wave harmonic to build up in the skull resulting in memory loss or pseudo-religious visions, but their findings have never been replicated by the aluminum foil research community at large. Even if their findings are validated, the risk involved is small compared to the potential of mind-intrusion.
      • by Anonymous Coward on Sunday June 20, 2004 @06:48AM (#9477503)
        For Linux users, MindGuard [zapatopi.net], free software that turns your computer into an effective mind control ray jammer!

        MindGuard is a program for Amiga and Linux computers that protects your mind by actively jamming and/or scrambling psychotronic mind-control signals and removing harmful engrammic pollutants from your brain. It also has the ability to scan for and decipher into English specific signals so you can see exactly Who wants to control you and what They are trying to make you think.

        MindGuard works by leveraging your computer's aluminum-based innards to both detect and emit psychotronic energy using advanced quasi-quantum techniques. Once a mind-control signal is identified and analyzed, MindGuard can generate a specially tuned anti-signal that will jam the incomming signal. If MindGuard is unable to properly identify the signal, it will generate psychotronic white noise to ensure the signal's harmful message is scrambled.
      • a...l...u...m...i...n...i...u...m

        please!
        • by Fishstick ( 150821 ) on Sunday June 20, 2004 @07:43AM (#9477612) Journal
          RTFWS:

          * FOOTNOTE: The American spelling** of aluminum is used here. If you are searching for more information on aluminum, be aware that the British spell it "aluminium" (and pronounce it accordingly).

          ** HISTORICAL FOOTNOTE: Aluminum was originally named "alumium" by Sir Humphry Davy, who later changed it to "aluminum" (perhaps in an attempt to make it more Latinized since alumen is Latin for alum, the aluminum compound that the name is derived from). The British (and allied English speakers) shortly thereafter changed the name once more, this time to "aluminium" so that it would again match the pattern of most other elements (helium, sodium, etc.), while the North Americans eventually decided to keep the second, slightly more traditional name. I predict that North Americans will adopt the more regular "-ium" spelling by the year 2050, prompting the British to start calling it "alumininium". At that point debate can begin on changing "platinum" to "platinium"

          ;-)

          • by Deadstick ( 535032 ) on Sunday June 20, 2004 @10:06AM (#9477939)
            match the pattern of most other elements (helium, sodium, etc.)

            The pattern of most other metals, not most other elements. Every element ending in -ium is a metal except helium. The latter was first observed on the sun, via spectrometry, and was believed to be a metal, so it was named "sun metal" in Latin. By the time it was found on earth, it was too late to change the name.

            rj

            • The pattern of most other metals, not most other elements. Every element ending in -ium is a metal except helium. The latter was first observed on the sun, via spectrometry, and was believed to be a metal, so it was named "sun metal" in Latin. By the time it was found on earth, it was too late to change the name.

              -ium vs -um in Latin doesn't have anything to do with the elements being metals or not. Just look at the names of the different elements and you'll see a heap of non-metals ending in -ium: Hydroge

          • That's close. According to Chemical Division of Los Alamos National Labs, the history of alumin(i)um [lanl.gov] is:

            (L. alumen: alum) The ancient Greeks and Romans used alum as an astringent and as a mordant in dyeing. In 1761 de Morveau proposed the name alumine for the base in alum, and Lavoisier, in 1787, thought this to be the oxide of a still undiscovered metal.

            Wohler is generally credited with having isolated the metal in 1827, although an impure form was prepared by Oersted two years earlier. In 1807, Davy pro

      • You can keep your hat, I'm going to stealth out my DIY cruise missile... [interestingprojects.com]

        On second thought, I'm going to need a hat too.
      • For trivia buffs: The reason aluminum foil has a shiny side and a flatter side is that it is rolled into shape. The process involves passing what starts as an ingot through many sets of rollers, each set spaced closer together than the last. When the rollers get very close, they tend to flatten out against each other and jam. Someone had the bright idea to fold two sheets together and run them both through the last set of rollers at once, then peel them apart. Thes lets the last set of rollers be spaced as
  • by Bender_ ( 179208 ) on Sunday June 20, 2004 @06:02AM (#9477398) Journal

    Ok, its nice. This wallpaper blocks a lot of RF radation. This means that you can not use WLAN, cellphones and terrestrial TV/Radio. Is this really what you want?
    • Sounds good if you're doing a makeover of, say, a secure military area.
      Obviously you can still pipe stuff through wires. (you know, those plastic/rubber coated strings of metal? remember them?)
    • Ok, its nice. This wallpaper blocks a lot of RF radation (sic). This means that you can not use WLAN, cellphones and terrestrial TV/Radio. Is this really what you want?

      It's what defense contractors, the government, and businesses worried about industrial espionage by employees, want.

      And given that Witchfinder General Ashcroft [wikipedia.org] and Big Blunkett [wikipedia.org] are in power, I'm sure it will not only sell well, but be heavily subsidized by government, and probably required on certain government contractors.
    • by aussie_a ( 778472 ) on Sunday June 20, 2004 @06:14AM (#9477430) Journal
      we prefer the term reality-challenged.

      Hey, I had to make a joke about something. 3 other people took my tin-foil hat joke :(
    • RTFA (Score:5, Informative)

      by cperciva ( 102828 ) on Sunday June 20, 2004 @06:14AM (#9477431) Homepage
      This means that you can not use WLAN, cellphones and terrestrial TV/Radio. Is this really what you want?

      Quoth the article:
      The company has produced panels using the technology to produce a screen that will prevent outsiders from listening in on companies' Wi-Fi traffic but let other radio and mobile phone traffic get through.
      • so it will block only 2.4ghz? or 5 as well? or nothing at all? it has the makings of a snakeoil in it(besides.. really, should you be using wifi if you don't wany anyone outside the room to detect it? if you absolutely must have wireless wouldn't some low power bluetooth be better?).

        802.11b and 802.11g standards transmit at 2.4 GHz,
        802.11a standard transmits at 5 GHz.

    • I guess you can use WLAN inside your apartment, as long as you use this kind of wallpaper on your outside walls only. Then the radio waves can pass through the inner walls, though not outside (your garden, e.g.).

      Cellphones won't work, but TV and radio could, if the antenna is outside (on the roof) and the signals are distributed via cable. And cable TV/radio works too, of course.

      I'm not sure how big the market really is. A few people are concerned with the increasing amount of radiation (TV, GSM, UMTS
      • Regarding health issues, there is no definitve answer.

        There is a definitive answer when you are talking about non-ionizing radiation like radio waves: if there is any deleterious health effect, it is so small that it cannot be reproducibly measured even in studies involving tens of thousands of individuals.

        Pampered Western worry-warts would do well to drop their concerns about non-ionizing radiation from power lines and cell phones, and worry more about things with real consequences like what they eat a

  • I'm really busy (Score:5, Interesting)

    by isoprophlex ( 659648 ) on Sunday June 20, 2004 @06:03AM (#9477400)
    I will be wonderful when the adhear this technology in movie cinemas so that the wankers sitting behind me who answer there phones during the films, can't take their "important calls".
    • Seriously. The parent sounds like a valid application of this technology.
      • Yes, hospitals too. (Score:5, Interesting)

        by teidou ( 651247 ) <tait@f i t i s . com> on Sunday June 20, 2004 @08:01AM (#9477653) Homepage
        Most people don't understand why hospitals would use this: every hospital I have worked in would be interested.

        Cell phones, even by being on can affect drug infusion pumps: it is not good to have the infusion rate spontaneously jump from 1 mL/min to 100mL/min. What's worse is that some people don't know the difference between "standby" and "off" - they think just not using it will turn off the transceiver. (Yeah, yeah, Snopes [snopes.com] says it's not a big problem. They're FOS on this one: it really does happen).

        Some visitors argue it is a problem with the medical equipment and they should get to keep their phone on: 1) possibly a valid point, but the fact is that patient health is threatened by the phone, and 2) the historic FCC position is that RF shall not interfere with other equipment. (Incidenally, new medical equipment is better shielded (hinted at on the FDA website [fda.gov]).

        Finally, to the genius who wants to point out that many hospitals are using wireless for notebook computing and wireless monitoring: 1) those in use are on different frequencies than cell phones, and 2) they are very carefully tested before implementation, (Also, I'm not sure on this point, but I believe they are probably less powerful than cell phones; this is why repeaters are in every hallway rather than just one on the roof. If the wallpaper is just on the exterior of the building, I doubt it would not interfere with current use).

        Teidou
        • by way2trivial ( 601132 ) on Sunday June 20, 2004 @09:17AM (#9477817) Homepage Journal
          wrap the drug infusion pumps...
          I bet it would cost a lot less than wallpapering the entire hospital...
        • by Myself ( 57572 ) on Sunday June 20, 2004 @09:24AM (#9477830) Journal
          While you're right that it's the transmitter's responsibility not to cause interference, I still think it's dangerously irresponsible to keep old machines in service that've proven themselves unreliable in the face of common interference.

          You make an excellent point that the WLANs used in hospitals are very low power. Yes, they put APs every few yards down the hallways, so that the portable devices never have to step up their transmit power to reach one.

          The solution to the cell phone problem in hospitals is to put base station equipment IN the hospital and run Radiax down the hallways. Alternately, just put cell sites as close to the building as possible. When the phones can reach a tower easily, they'll limit their output power accordingly.

          This is also the counterintuitive solution to the weenies who protest when a cellphone company wants to put a tower near the high school. (This frequently happens when an athletic field is getting new lights.) Compare a cordless phone to a moonbounce transmission, which requires more power?

          The first mobile phones weren't cellular, there was a single base station in the center of town. The powers used were on the order of 50 watts, so it's a good thing the vehicle-mounted antenna was several feet from the handset. When cellular was developed, it meant you were always within a mile or two of a tower, so the power levels decreased drastically. Phones reduce their output power in response to requests from the tower, because it's easier for the tower to "hear" the faint phones if the near phones aren't screaming.

          Shielding the place into an RF hole is counterproductive. In the event that someone forgets to turn their phone off, it'll sit there chirping out its maximum transmit power every once in a while, searching for a tower it can't find. Worse yet, it'll maintain contact with a tower it can just barely hear, only if it really blasts out the RF. This helps nobody.
    • Re:I'm really busy (Score:4, Informative)

      by arcade ( 16638 ) on Sunday June 20, 2004 @06:19AM (#9477445) Homepage
      Oh how I would love that application of it in Norway. Unfortunately it's not allowed. The "problem" with this solution is that if there happens an accident - one "should" be able to call the norwegian equivalent of 911.

      I think it sucks too.
    • by Anonymous Coward
      Phones have a vibrate mode for more than sexual pleasure. people should use it!!
    • Re:I'm really busy (Score:5, Insightful)

      by aflat362 ( 601039 ) on Sunday June 20, 2004 @08:27AM (#9477711) Homepage
      I agree that cell phones are abused way too often. (Jerks taking useless calls in a theater is a prime example)

      However, we should never block cell phone reception anywhere.

      What if a doctor were to go watch a movie and one of his patients started dying and he needed to be contacted? What if a loved one were in an accident and people were trying to get ahold of you so you could possibly see them before they died?

      There are many scenarios where having cell reception is important.

      Just try to use the vibrate or silent mode. I can deal with people forgetting to turn their phones off in a movie (though I myself have the courtesy to turn mine off), as long as they don't yack on them in the theater.

      • Re:I'm really busy (Score:5, Interesting)

        by nacturation ( 646836 ) <nacturation@gmai l . c om> on Sunday June 20, 2004 @09:42AM (#9477872) Journal
        What if a doctor were to go watch a movie and one of his patients started dying and he needed to be contacted? What if a loved one were in an accident and people were trying to get ahold of you so you could possibly see them before they died?

        There are many scenarios where having cell reception is important.


        Man, what *did* people do before cell phones? Give out the public number to the theatre/opera/amusement park/restaurant/stadium's land line and have an employee come and get them if they got a call?

        Actually, an interesting note is that some classy restaurants offer this as a service. They ask you to forward your cell phone to a special number, let them know your name and where you're sitting, and the restaurant staff picks up the call and comes and gets you. "Excuse me, Mr. Smith, but you have a call. This way please..."
      • Re:I'm really busy (Score:3, Informative)

        by AmunRa ( 166367 )
        What about if the doctor went to the cinema and the local cell transmitter went down? Cell-phones have no SLA (service level agreement), so a doctor has no guarantee that he will get service in the cinema anyway.
        Plus when I worked in a cinema here in the UK, we had a scren that was underground, and you couldn't get reception there _ever_!

        The way I see it, if a cinema puts up a notice saying that cellphones are not allowed in the auditorium, then there's nothing wrong with them using technology to inforce i
      • Re:I'm really busy (Score:3, Insightful)

        by Bagheera ( 71311 )
        I agree that cell phones are abused way too often. (Jerks taking useless calls in a theater is a prime example)

        Yes, I think we all agree on that.

        However, we should never block cell phone reception anywhere.

        Bullshit. We should never block reception EVERYwhere I can agree with, but not ever anywhere.

        There are some places where it is simply inappropriate to even HAVE a cell phone. Say, an operating suite? Do you REALLY want the RFI, or someone distracted by a call while you're on the slab?

        No? Didn
  • by afriguru ( 784434 ) on Sunday June 20, 2004 @06:04AM (#9477401) Homepage
    UK defence contractor BAE Systems has developed a stealth wallpaper to beat electronic eavesdropping on company Wi-Fi and wired LANs.
    Instead of qoing through the hassle of covering a building with this wallpaper, why can't system admins just get into the habit of implementing encryption all the way (particularly for Wi-Fi networks?)
    • by Cska Sofia ( 705257 ) on Sunday June 20, 2004 @06:10AM (#9477420)
      Why take the risk of an outsider breaking your encryption if you can prevent their access to the signal in the first place?
      • by afriguru ( 784434 ) on Sunday June 20, 2004 @06:15AM (#9477434) Homepage
        The attacker may well be inside the building; business offices are generally not run as military zones! And what about the windows of the building; will they be covered too? Breaking high encryption is probably not as easy as bribing a staff member to for access.
        • by qtp ( 461286 )
          I would be surprised if the military was not encrypting the traffic as well. Even if you do have the link encrypted, it is still better if "the enemy" does not know that a message was passed in the first place.

      • by BlueWonder ( 130989 ) on Sunday June 20, 2004 @07:32AM (#9477588)

        When planning a security system (not restricted to computers, I'm talking about security in general), it's usually a good idea to take into account what an insider can do. Most often, what an insider can do is a strict superset of what an outsider can do, so if your system is secure against attacks from insiders, it's automatically also secure against attacks from outsiders.

        In the case at hand, it might be possible to use separate cryptograhic keys for separate groups of insiders, just like not every employee in a large company has a door key for every single door in the building. Restricting the signal by means of a wallpaper could be harder.

    • by Richard_L_James ( 714854 ) on Sunday June 20, 2004 @06:16AM (#9477437)
      The answer to your question is right at the start of the text you quoted:

      UK **defence** contractor

      For some applications encryption isn't enough. Note also that WEP is a commercial encryption system this means it is NOT secure enough for very serious military applications which is where technologies like this play a role by preventing leakage or blocking interference.

      • Because if you emit RF, you're giving your opponent another way to track your position. I'm not a military strategist, but advertising your position and time of presense (increased activity) sounds like a bad idea to me.
      • I see we have a new member of the "I can sprout bullshit and get +5 club."

        (a) If you are so worried about interception that you think cryptography is not enough (meaning you are worried about traffic analysis and alike) then you won't be using a wireless network anyways.

        (b) WEP is not secure enough for any application. When the grandparent said encrypt things, he didn't necessarily mean WEP: for example, run an encrypted VPM over the WIFI network. WEP may suck, but claiming that commercial encryption syst
    • by hot_Karls_bad_cavern ( 759797 ) on Sunday June 20, 2004 @06:23AM (#9477454) Journal
      "Why not just encrypt?"

      Uh, when's the last time you had the electrons from your monitor's gun encrypted on the way to the screen? Right, never. That's what i thought...there are many, many forms of RF that can give away what it is that you are doing on a computer...encryption is only the beginning of the game.
    • by Myolp ( 525784 )
      Instead of blocking signals to prevent eavesdropping, this could actually be used in rooms where you don't want a constant RF-signal passing through, like your childrens bedroom or something.

      The main reason I don't want WiFi in my home is the potential health-risk. If I could limit the RF-field to certain rooms, I just might consider it.
      • I have a feeling the field strength in your home from nearby TV and radio transmitters, not to mention hydrogen-alpha radiation from the universe at large, is much higher than a WLAN would be. Do you live in a shielded box?
  • You still need a good Faraday cage to block everything.
  • by MachDelta ( 704883 ) on Sunday June 20, 2004 @06:05AM (#9477408)
    Dude! Couple this with some lead-painted shingles, and a couple of those dentists X-ray aprons for curtains, and my house will finally be impenetrable to their prying eyes (and ears).

    At last! A sanctuary!
  • ...to block RF? I'm sure you can select what frequencies by the size of the mesh. Though not as cool as wallpaper, that's for sure.

  • by orin ( 113079 ) on Sunday June 20, 2004 @06:08AM (#9477412)
    If you were concerned enough about Wi-Fi security to buy this stuff, wouldn't you consider Wi-Fi enough of a security problem to ban it from your network environment? And what if this stuff doesn't come in the right color? Also - does anyone use IPSec on Wi-Fi networks? (given that WEP can be cracked with a large enough data capture)

    • You may want the flexibility of wireless, without the security risk. No harm in trying to find a way to have your cake and eat it too. ;)
    • by Homology ( 639438 ) on Sunday June 20, 2004 @06:54AM (#9477514)
      Also - does anyone use IPSec on Wi-Fi networks? (given that WEP can be cracked with a large enough data capture)

      OpenBSD has built-in support for IPSec, so it was quite easy to setup for WiFi. The OpenBSD firewall at home is functioning as an access point, and only IPSec related/authenticated traffic is allowed. So when I boot up the older laptop - that is also running OpenBSD - I'm up and running securely. And fast, since no encryption is done on the WiFi chipset, and thus freeing the chipset for handling packets only.

      OpenBSD really makes it straightforward to setup a secure, functional and stable home gateway.

  • by dj245 ( 732906 ) on Sunday June 20, 2004 @06:08AM (#9477415)
    Have you any idea how much harder it is to make hats out of wallpaper than it is out of tinfoil?
  • by lokedhs ( 672255 ) on Sunday June 20, 2004 @06:09AM (#9477418)
    I mean, if you have such sensitive data that you need to install this, why not simply use copper cables, and spare yourself the hassle (and sleepless nights in case the cat tears the wallpaper).
  • Interesting (Score:5, Interesting)

    by hot_Karls_bad_cavern ( 759797 ) on Sunday June 20, 2004 @06:20AM (#9477446) Journal
    For sometime i've wanted to have my main workstation off the network, grid and inside a faraday cage. But think about how ridiculous that would be/look? The other machines in the house would be okay to leave alone, but i'd want at least one that i knew was safe (data transfers would be on extreme need only, i.e. data sets into and encrypted messeges written inside).

    But i'm getting away from my original point: this is sweetness. No, it's not exactly what i'm looking for, but it's a stop in the correct direction. Think you've never had a neighbor whom owns a 900MHz scanner? Anyway, i think this is great. You and i both know that information, its protection, secure dissemenation, and reliability of said information are the weapons of the upcoming century. You need to have your data safe whether you think so or not, so the more things like this the better.
  • by KitFox ( 712780 ) on Sunday June 20, 2004 @06:31AM (#9477470)
    What about the windows and doors? RF goes through them too. I could just see somebody wallpapering their ceiling also. (It's such a lovely print though!)

    It really strikes me as a product for the "Security-Concerned-But-Uninformed", because I really wonder how many companies that want to use this will block other means of RF egress. And those that don't will simply have a false sense of security and a big hole in their "defenses".

    Believe me, I'm literally right across the hall from a "RF-Secure" room at times, and that has EVERYTHING covered in every direction, windows, doors, floor and ceiling.
    • Glass can be coated with a "transparent" (ok not really transparent but it looks like window tinting) conductive material that will block various ranges of em radiation. We have used it in the past with gauss cages to build em isolation rooms for conferences
    • What about the windows and doors?

      I suspect that many of the rooms this has been designed for are unlikely to even have Windows. However quoting the article: The panels are 50 to100 microns thick and can be applied to most surfaces including glass.

      Believe me, I'm literally right across the hall from a "RF-Secure" room at times, and that has EVERYTHING covered in every direction, windows, doors, floor and ceiling.

      Oh I believe you!! The military have been known to paint entire rooms 100% black (inclu

  • by ross.w ( 87751 ) <rwonderley@[ ]il.com ['gma' in gap]> on Sunday June 20, 2004 @06:36AM (#9477484) Journal
    I want to put this stuff on my car.

    No more radar speed traps!
  • Stealth wallpaper could keep LANs secure

    June 18 2004, by Ron Coates

    UK defence contractor BAE Systems has developed a stealth wallpaper to beat electronic eavesdropping on company Wi-Fi and wired LANs. The company has produced panels using the technology to produce a screen that will prevent outsiders from listening in on companies' Wi-Fi traffic but let other radio and mobile phone traffic get through.

    The FSS (Frequency Selective Surface) panels are made in the same way as printed circuit boards -

  • Good greif.

    It's high tech, it can block wifi! So can standing in front of the antena.

    Find a tastefull way to tape aluminum foil to all your walls, without looking like a kook, and I guess you can make a million.
  • that's the same as a Faraday cage [wikipedia.org]. No signal in means no signal out!

    Does that mean I can't patent my own copper wire net?

    Can you patent the laws of physics?

    If yes, I patent the gravity and demand fees for using my patent....

  • by rapiddescent ( 572442 ) on Sunday June 20, 2004 @07:16AM (#9477551)
    would be to cover my car with this material to prevent getting snapped by one of the 20,000 GATSO speed cameras in the UK... rd
  • Alright...! (Score:5, Funny)

    by igrp ( 732252 ) on Sunday June 20, 2004 @07:25AM (#9477570)
    BAE, the British defense contractor, has announced that the same material used to foil radar by stealth bombers can be used to selectively block certain frequencies and prevent wireless networking signals from entering or exiting a building.
    So... what they're saying is that all I need now is a whole bunch of their wallpaper and a cessna and I could have my very own stealth plane?

    Cool... Be the first kid on your block to own your own flower wall paper stealth plane.

  • Shielding is Hard (Score:5, Interesting)

    by Detritus ( 11846 ) on Sunday June 20, 2004 @07:28AM (#9477578) Homepage
    Assuming that you cover the walls with this stuff, you still have to worry about the floor, ceiling, windows, doors, ventilation ducts, plumbing and electrical wiring, plus any holes or gaps in the shielding. Then there is telephone, LAN and video wiring to worry about.
  • by hashwolf ( 520572 ) on Sunday June 20, 2004 @07:37AM (#9477596)
    ...the British defense contractor, has announced that the same material used to foil radar by stealth bombers can be used to selectively block certain frequencies and prevent wireless networking signals from entering or exiting a building.

    In a related article:
    Wallpaper coated cessna evades radar detection.
  • by G4from128k ( 686170 ) on Sunday June 20, 2004 @07:37AM (#9477597)
    Stuff like this will restore the peace and quiet to theaters and restaurants. And the passive nature of the material means it should not run afoul of U.S. FCC regs on "interference" (I don't know about other countries' rules).

    Assuming the material is actually absorptive (not reflective) at cell-phone frequencies, it would also reduce the passage of cellphone signals into and out of airplanes and reduce any chance of passenger's cell phone transmissions from interfering with the airplane's electronics or the ground-based cells they are flying over.

    Finally, they could use the stuff to help separate WiFi networks in office and apartment buildings. A layer of the stuff under the carpet or in the ceiling would keep wifi signals confined to a single tenant's floor or section of the building so that different tenant's wireless nets don't collide.
  • lead walls? (Score:4, Funny)

    by ylikone ( 589264 ) on Sunday June 20, 2004 @07:46AM (#9477620) Homepage
    After all the effort everyone has gone through to get rid of lead-based paint on the walls?
  • by SharpFang ( 651121 ) on Sunday June 20, 2004 @07:49AM (#9477629) Homepage Journal
    who first starts selling paper hats made of that wallpaper.
    Definitely better than tinfoil.
    I guess ThinkGeek would find many customers on slashdot...
  • by rayd75 ( 258138 ) on Sunday June 20, 2004 @08:02AM (#9477655)
    She constantly embarrasses me by explaining to visitors that our wireless network is secure because "we only use the lower power equipment that is hard to pick up outside the building". Never mind the DMZ, L2TP tunnel, MAC filtering, client firewalls, etc. Oh well, at least she is letting me keep the access points turned on more often these days.
  • by shpoffo ( 114124 ) <<gro.airdnaxelawen> <ta> <mapson>> on Sunday June 20, 2004 @08:14AM (#9477678) Homepage
    Does this sound to anyone else as causing similar problems as reported by a study from the UK (reported here on /.) about cel phone usage in trains raising the ambient radiation levels about those deemed safe by regulatory committees? When the waves are 'blocked' I get the sense that they're reflected back into the space. Probalby makes for a stronger signal, but you'll also get radiation build-up, and perhaps focusing effects - where you'll get small spaces where there will be a literal 'hot spot.' Everyone could go and set their food on the left corner of the third filing cabinet from the end of Dave's cubicle for a few minutes to heat it up before lunch......

    yuck

    .
    -shpoffo

  • What I'd Like... (Score:3, Interesting)

    by Gyorg_Lavode ( 520114 ) on Sunday June 20, 2004 @08:21AM (#9477694)
    You know what I'd like. A clear, (well colorless as in it wouldn't make my walls look funky), coating I can paint on in my apartment to try and block out whoever the bastard w/ the 2ghz phone is. It farks up my wireless at least every other night.
  • by Alexis de Torquemada ( 785848 ) on Sunday June 20, 2004 @08:23AM (#9477700)
    Sounds good, where can I download it?
  • by macemoneta ( 154740 ) on Sunday June 20, 2004 @08:31AM (#9477723) Homepage
    My mom always loved the foil/felt (flock) wallpapers in our dining room, when I was growing up (about 40 years ago). The foil was always grounded, because it went under the (metal) outlet and switch covers, which in turn grounded to the (metal) box. I know the foil was conductive, because we once had a two-wire appliance short to it's metal case (before the days of 'double insulated' design), and I got a shock touching the wall and appliance.

    Maybe companies selling this kind of wallpaper should rebrand it as inexpensive high-tech (but low cost) Faraday shielding. And maybe the defense agency could save a few billion dollars by using an off-the-shelf solution. Nah.
  • by qtp ( 461286 ) on Sunday June 20, 2004 @08:45AM (#9477758) Journal
    The computer room (floor, walls, and ceiling) was lined with akluminized wallpaper, the window had an aluminum screen. His own home-built faraday cage.

    As he did not have wi-fi, I beleive that he was more concerned with preventing eavesdropping of his CRTs rf feild. There were other CS guys (from the uni) who did the same thing.

    As he my first real programming teacher, I always assumed that the tech to "tempest" a CRT was available then. Tapping WiFi is undoubtably a magnitude simpler.

  • I wonder (Score:3, Interesting)

    by BCW2 ( 168187 ) on Sunday June 20, 2004 @08:46AM (#9477759) Journal
    if the foil coated sheathing panels put under the siding of some houses does the same thing? Or someone might make a fabric version to be used like Tyvek as a house wrap during construction. Then everything stays in the house.
  • by Moblaster ( 521614 ) on Sunday June 20, 2004 @08:49AM (#9477766)
    I keep telling my mom that my room is classified and off-limits. Now with my Stealth-fighter wallpaper, I'll be able to call the Feds any time she breaches the perimeter.
  • Relaxation (Score:5, Funny)

    by beforewisdom ( 729725 ) on Sunday June 20, 2004 @09:18AM (#9477820)
    Now the truly paranoid can come home from work and relax by taking their foil hats off - unless - the material used to make the wall paper is fault.

    Heh, this whole story is probably fictitious. A plot from the government to get citizens who are on to them to let down their good.

    Phew, almost got suckered in.
  • by Jott42 ( 702470 ) on Sunday June 20, 2004 @09:25AM (#9477831)
    The FSS, or frequency selective surface, which is used in the panels described in the article works as a frequency selective filter to an electromagnetic wave. The one by the british firm is used as a stop band filter, which lets everything except WiFi-frequencies pass. It is also possible to make FSS which works as pass-band filters, usually for radar applications. (Stealth planes incorporates FSS in order to have a reflecting surface for the enemys radar, but which is still transparent for the planes own radar.)

    So it is very different from ordinary aluminium foil. Foil wallpaper and window treatments have been available for quite a while, both for security applications and for people concerned about electromagnetic radiation. But these blocks all frequencies.
  • RF Proof clothes? (Score:3, Interesting)

    by freeduke ( 786783 ) on Sunday June 20, 2004 @09:34AM (#9477853) Journal
    That could be cool to build RF proof clothes with a tissue that has the same properties as this wallpaper. So that you could hear your cell phone, without fearing for your health! ok, problem arise when you put it in one of your pockets and wait for a call...
  • Reuse (Score:3, Interesting)

    by Doc Ruby ( 173196 ) on Sunday June 20, 2004 @10:26AM (#9477990) Homepage Journal
    Sure, the RF power it absorbs is tiny. But is there a way to capture that power for reuse? Like a solar collector, powered by our RF devices?
  • by dougmc ( 70836 ) <dougmc+slashdot@frenzied.us> on Sunday June 20, 2004 @11:22AM (#9478149) Homepage
    Is this the next take on lining the walls with lead?
    No, it's not. To block a RF signal all you need is a faraday cage -- which can even have lots of holes in it (like a wire cage) as long as the holes are a good deal smaller than the wavelength of the signal you're trying to keep out.

    Wrapping the whole places in tinfoil would work nicely as well, as long as you don't leave any holes. No need to go to anything as heavy as lead, unless you're trying to block things like X-rays or gamma rays.

  • RFID (Score:3, Interesting)

    by bigbigbison ( 104532 ) on Sunday June 20, 2004 @11:56AM (#9478237) Homepage
    So I could take this to a store, wrap an rfid tagged item in it and steal it? So you are saying that a new technology can easilly be circumvented by criminals and therefore only serves to annoy and monitor law abiding citizens? That's umpossible!

Order and simplification are the first steps toward mastery of a subject -- the actual enemy is the unknown. -- Thomas Mann

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