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Newly Declassified Window Film Keeps Out Snoops
Posted by
kdawson
on Tue Jul 03, 2007 01:41 AM
from the pricey-tinfoil-hat-for-your-house dept.
from the pricey-tinfoil-hat-for-your-house dept.
An anonymous reader writes to describe a newly declassified window film from CPFilms Inc. that could give war drivers fits. Scientific American has the story, which includes a rather dismissive comment by Bruce Schneier.
"Once manufactured under an exclusive contract with the US government, this recently declassified window film is now available to the public. But don't expect to see it on store shelves anytime soon. Currently, it's only available directly from the manufacturer, and at prices that will likely make it prohibitive for all but the wealthiest home owners.
The two-millimeter-thick coating can block Wi-Fi signals, cell phone transmissions, even the near-infrared, yet is almost transparent... It can keep signals in (preventing attempts to spy on electronic communications) or out, minimizing radio interference and even the fabled electronics-destroying electromagnetic pulse generated by a nuclear blast."
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War Drivers (Score:5, Funny)
Re:War Drivers (Score:5, Funny)
Re:War Drivers (Score:4, Funny)
Re: (Score:3, Funny)
Like they said in the good ol' days.... (Score:4, Funny)
Does it come as hats? (Score:5, Funny)
Tin foil hat == government conspiracy (Score:5, Informative)
Re:Does it come as hats? (Score:4, Funny)
What about the walls? (Score:5, Insightful)
Re:What about the walls? (Score:4, Interesting)
Incidentally, the original article is down - slashdotted, already?. Does this tech work via the Faraday cage [wikipedia.org] principle similar to the mesh on your Microwave oven view window?
Re:What about the walls? (Score:5, Informative)
As a result the doors and the windows remain the sole way in and out for the radiowaves. While special films like the one described in the article can deliver a nearly perfect insulation, they are not necessary.
If what you are bothered about are script kiddies driving down the street (or in your neigbour's basement) or interference from your neigbour's AP standard K-glass (or similar IR reflective type) will do. In my previous company we did a survey prior to moving into a new office and the drops was by more than 30db in the 802.11b/g band (in layman terms from 95% "quality" to sub 5%). In fact the drop from K-glass was more than the drop through a concrete floor covered by a steel plated grounded raised floor.
Re:What about the walls? (Score:5, Informative)
voila, no wifi or cellular.
Using a special expensive window film is silly, replace your screens with aluminum screens and magically they also no longer pass RF energy.
I get a kick out of all this "new" stuff coming out. Anyone that owns a home that was re-sided in the 70's and 80's typically has aluminum siding and aluminum screens and therefore is mostly living in a faraday cage. (except roof)
Most of the new metalized layers on new construction materials (if any is used) dont block RF worth a darn. I tried them all at new construction sites and none were as effective as good old aluminum sheeting and screening.
Re: (Score:3)
Re: (Score:3, Informative)
A rebar wall makes a fairly good Faraday cage, but mostly only the pillars are rebar. Many recent office buildings have 100% glass walls. The film would work ok there. On a building with walls, then a lot of signal normally leaks through. Yes, the posters
Re: (Score:3, Informative)
That said, it seems that the big difference between them and this "declassified" one is that it seems to be optically transparent? If you d
yeah, but.... (Score:4, Interesting)
yeah, but what about the walls? will the walls block it? if not then this stuff is not useless, but not as effective as one would imagine. not to mention that if a nuke went off I think we would have more problems than some EM pulse coming in through the windows...
Just make your house into one big Faraday cage, but what about the chimneys?
what I'm trying (and probably saying) is that you plug a hole, the waves will go through another. (not saying that we shouldn't plug them, just that we can't really stop until it is all sealed, in which case you live in a bubble.)
Re: (Score:3, Interesting)
Re: (Score:2, Interesting)
However, there is no conceivable way that a plastic film embedded with any sort of thin, transparent conductor will be able to h
Re: (Score:3, Insightful)
Re:yeah, but.... (Score:5, Informative)
Can't blame the editors. The claim regarding resistance to EMP is a direct quote from (the ad copy embedded in the middle of) TFA. Morever, what TFA has to say about the film and EMP is that it is "capable of minimizing radio interference and even...EMP." They don't say block it, they say minimize it. The effective frequency range of the film is 10 Hz. up to "just shy of visible light" so I'd say they at least have a shot at it.
Now, EMP is what, again? Oh, yeah, Electro-Magnetic Pulse. Put another way, a really, really strong blast of RF interference. Anything that can completely block cell phone and wifi signals will at least somewhat hold back EMP. TFA goes on to say that one of the things that makes the film so effective is that it's part of a completely package. The film is only one component of what you're buying. Sounds like they probably retrofit the building with some kind of Faraday cage-like gear.
EMP doesn't melt plastic, it fry's electronics [frys.com]. Well, if you were so close to the hypocenter that the EMP could melt a 2 mm plastic film on the window, that would be the least of your problems, because if you didn't get vaporized at about the same time, the shockwave that arrived shortly thereafter would blow you, the window, and maybe the wall to the other side of the room.
The EMP they are trying to guard against is the high air burst kind (think huge warhead detonated in LEO over the US east coast) which is intended to take down electrical grids, telephone networks, and as much of everything else electronic as it can. A lot of Soviet (and presumably now Russian) scenarios included such an air burst as an early shot. Get one of those in position undetected and detonate it and you're then in a position to do a couple of things, such as:
If you have your buildings protected to the best possible extent by EMP shielding such as that stuff, it might allow you to launch in such a scenario before the other side does. You'd pretty much have to, because the EMP would fry the recon sats that would normally tell you if they were launching or not. You'd have to assume they were.
Re: (Score:3, Insightful)
I dont suppose you would be someone to think that shorting some 20 gauge wire in an electrical socket won't vaporize the wire? Why dont you try picki
Re: (Score:3, Informative)
EMP was a known threat during the cold war and military electronics were designed to withstand EMP.
I worked as a technician for AT
Should have better defined "film" (Score:5, Funny)
Re: (Score:2, Informative)
Cinema Wallpaper (Score:5, Insightful)
Re:Cinema Wallpaper (Score:5, Interesting)
Re: (Score:3, Interesting)
Re:Cinema Wallpaper (Score:5, Insightful)
This is an interesting theme that pops up every time this sort of discussion takes place. I sometimes get the idea that the entire populace is just shivering with dreaded anticipation - waiting for that fateful cell phone call or text message to tell them that some horrible accident or disease has descended upon family or friend. That if they are out of contact for mere moments, they will live the rest of their lives in anguish because they failed to rush to someone's deathbed for the final conversation.
It's really OK not to be in touch with everyone 24x7. We are not Borg just yet.
Turn the damn things off and enjoy life.
Re:Cinema Wallpaper (Score:5, Insightful)
At the danger of sounding harsh, but what do you expect to do if your loved one is being rushed to the hospital? Stay and enjoy the movie (without knowing it, or the enjoy part is over). You can't do jack there anyway except standing in the way of the docs trying to save him/her.
old news (Score:5, Interesting)
"Tinfoil hat" for your home blocks comms; Wednesday June 27, @01:06PM; Rejected
If you want to keep up with news like this (recall that "news" comes from Middle English for "new thing") just drop New Scientist [pheedo.com] and Scientific American [sciam.com] into your RSS reader.
Re: (Score:3, Insightful)
I've lived in the 21st century for too long. Now it just means "noise".
Hats? (Score:5, Funny)
people aren't wearing enough (Score:5, Funny)
Exec #1: Item six on the agenda: "The Meaning of Life" Now uh, Harry, you've had some thoughts on this.
Exec #2: Yeah, I've had a team working on this over the past few weeks, and what we've come up with can be reduced to two fundamental concepts. One: People aren't wearing enough hats. Two: Matter is energy. In the universe there are many energy fields which we cannot normally perceive. Some energies have a spiritual source which act upon a person's soul. However, this "soul" does not exist ab initio as orthodox Christianity teaches; it has to be brought into existence by a process of guided self-observation. However, this is rarely achieved owing to man's unique ability to be distracted from spiritual matters by everyday trivia.
Exec #3: What was that about hats again?
Exec #2: Oh, Uh... people aren't wearing enough.
Exec #1: Is this true?
Exec #4: Certainly. Hat sales have increased but not pari passu, as our research...
Exec #3: [Interrupting] "Not wearing enough"? enough for what purpose?
Exec #5: Can I just ask, with reference to your second point, when you say souls don't develop because people become distracted...
[looking out window]
Exec #5: Has anyone noticed that building there before?
Say goodbye to using your cellphone indoors!!! (Score:2, Interesting)
Anyways,
Just what we al needed (Score:5, Insightful)
No Thanks!
Don't mind a bit if movie theaters heap several layers on the ceiling, walls, and seats though. I'll help put 'em up.
I read the subject as... (Score:3, Insightful)
I was like... 'wtf would Microsoft have done that was classified?' I still think it would have been more interesting that way.
This is non-news. Just some crap that will be bought by the paranoid. Whats next? Roofing underlayment that blocks free radicals?
Re: (Score:2)
Works great until you... (Score:2, Funny)
At last... (Score:5, Funny)
A few months back.. (Score:3, Interesting)
It appears to work exactly as promised, and honestly, in certain applications it is the only real way to secure wireless data.
The government declassifies technology all the time, usually after they've developed something better.
Re: (Score:3, Informative)
Place it directly over a cell phone, and the signal disappears, for instance. Place it directly between a wireless router, and your wireless card, and you cease to get a signal.
He in
Windows Tag? (Score:3, Insightful)
Ever wonder why there's a "Linux" and an "Apple" section, but no "Microsoft" or even cleverly abbreviated "M$"?
There's your tinfoil conspiracy.
And tinfoil isn't made from tin. Stop calling it that.
Re:Windows Tag? (Score:4, Funny)
Re:Windows Tag? (Score:5, Funny)
EMP? You mean electromagnetic pulse? (Score:5, Funny)
Now that's serious product testing.
Booom! (Score:4, Funny)
I'm sure being able to view mutant porn after nuclear devastation hits will be a great comfort. Well done to all involved.
Finally! (Score:5, Funny)
Not a bad thing (Score:3, Insightful)
A faraday shield is unintrusive (if implemented properly) and can't be ignored. Nobody thinks their rights are being violated when they can't get a signal
Re:Cell Phones (Score:3, Informative)
Not always. Once you have a sealed RF container, you have the choice of what to let in and what to keep out. For example an active Cell/Pager
Re:if it were effective, it would still be classif (Score:5, Informative)
Not always. Many things that were classified are no longer classified because they became common knowledge and no longer required protection. Some examples are encryption standards, Nuclear basics, some radio modulation techniques, some CPU's, some radio frequencies, and much data from WWII. Even some of the SR71 information is no longer classified.
The fact a window tinting film can have a metalized film that blocks RF is now common knowledge. Others have stumbled upon the fact. Offices with metalic colors such as bronze, copper or stainless, have had problems with cell and pager coverage. GPS users have had reception problems in some vehicles. Many films are designed to reduce IR transmission to keep the heat out. With all that general knowledge, having a classified film with these properties is a moot point.
Just because it is declassified does not make it ineffective. The stealth fighter is still a low radar profile item.
It was classified when the film was used on the cockpit windows of stealth fighters to prevent radar reflections from entering the cockpit and having a retro-reflection back to the radar source. It's now common knowledge the stealth fighters have RF screens over things like Jet intakes and conductive films over windows so the plane's cavities do not reflect a signal back to the direction it came from. This lack of a reflection back to the source is what makes a stealth plane invisable to radar. Very little signal returns. All reflections are sent off to an angle, not back to the source. It's no longer a secret, so the film tech is now declassified.
If you don't want to spend big bucks for the official military product, visit your local car window tinting shop. Ask for a film that keeps out the heat and has a a nice metalic tint. Ask for samples. Take them outside and lay them on your GPS while watching signal strength. Pick from the ones that kill the GPS reception. Now you have one that blocks far IR, maybe near IR and radio. If you need to block near IR, take a IR modified webcam and see if it is transparant in the near IR. Most non-metalic window tints are water clear in the near IR. An IR camera sees through them like ordinary window glass.
Sample photos of IR and sunglasses and other materials. Caution, fabric photo may not be safe for work.
http://images.google.com/imgres?imgurl=http://www