Schneier on Security
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July 19, 2012
I just wrote about the coming age of invisible surveillance. Here's another step along that process.
The material is black in color and cannot be seen through with the naked eye. However, if you point a black and white camera at a sheet of Black-Ops Plastic, it becomes transparent allowing the camera to record whatever is on the other side.
What this means is you can hide a camera inside an object made of this special plastic and no one will know it is there. But the camera is free to record without having its view blocked.
The article doesn't talk about the technology.
Posted on July 19, 2012 at 6:46 AM
• 29 Comments
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and no one will know it is there
...unless they happen to take a picture of it with a black and white camera...
As a commenter on the source site asked, this looks like it's just IR-transmissive plastic, nothing special or new.
Probably just an IR camera. Almost all digicams are IR sensitive, they just have blocking filters over them - there's a fairly large third party market which removes those filters so you can shoot in IR. Then the "plastic" will just be an IR transparent but visible light opaque filter, like a Wratten 87.
If you really want to scare people - IR cameras can also "sort of" see through clothing - it works best with dark clothing with a thin material. There were plenty of scares a few years ago when people were using Sony IR video cameras at the beach to effectively "x-ray" the swimsuits. So if this stuff is deployed (for example, in shops) it may well show rather more than people are expecting, and cue some invasion of privacy concerns.
Either way, this tech doesn't appear to be anything new or clever...
While I guess people would be less suspicious of it than say, one way mirrors, it's only a matter of time and we'll all be suspicious of black panels too.
Mark II better come in a range of colours.
If what you want to do is hide a camera, there are plenty of simple ways to do it without IR-transparent plastic.
Moreover, fixed-focus and pinhole cameras are so small that you hardly even need to try to conceal them anyway, so what the hell.
Queue up the next threat to liberty; this one's a bust.
If this is just IR-transmissive stuff, it'll interact interestingly with the folks who have had lens-replacement surgery that lets them see IR, won't it?
I wonder if we'll see an uptick in elective surgery for this among the paranoid (or criminals, or security professionals).
Easy to spot. To be able to see an image through it, you need to have a gloss surface. A matte finish would scatter via refraction any light that does go through it. Not so useful unless you are specifically doing a bug sweep but if you are...
When I started reading this, I assumed that the point of camera-transparent plastic was for airline security. You make the passengers wear clothing that you can look through with a black and white camera...
If you look closely at the images on the vendor site, you'll notice a change in the light sources between the opaque and transparent images. You are probably correct in your IR assessment of the technology.
unless they happen to take a picture of it with a black and white camera...
Clever! Principle of reciprocity at work...
Lens replacements have been documented that permit vision in the UV spectrum. I dunno about IR.
When I read the headline, I was imagining flexible plastic. The TSA might require people wear camera-transparent clothing made of the stuff through airport security.
But I gather the plastic is rigid, so that's not a possibility.
@Doug D -- Same thing can / could be done with proper contact lenses. Remember some time ago that there were contacts that showed up under UV lights for easy locating if dropped, etc. Plus coloured lenses to change eye colour are still around, so not a big leap to have a soft lens that can do some filtering to see thru this stuff.
I believe TimW is spot on. Many things are transparent in the IR, including coca-cola.
for a first hand look at coke in the infrared! http://www.hoagieshouse.com/IR/
The human eye can't see IR, because the lens blocks it. Also, the retina is not very sensitive to IR. Contact lenses won't help, since they don't change either of these problems.
Human photoreceptors aren't sensitive to IR. In http://en.wikipedia.org/wiki/Photoreceptor_cell see the plot about 20% of the way down. By contrast, we see that the receptors *are* sensitive to UV (responses do not drop to zero at the short wavelength end of this plot.) (IR is >740 nm.) (I'm assuming this plot is for the actual cells, not the combination of cell plus filtering lens.)
This makes sense from a physics/photochemistry point of view: whatever chemical reaction is being triggered in the photoreceptor cells, it has some minimum activation energy. Photons with less energy (redder) than this energy cannot be detected.
This insensitivity is already used by back yard astronomers, who use red lights to see by without affecting their night vision (because the rods, the low light detectors, are not sensitive to red light - 'R' on the wikipedia plot.)
Espionage and the Candid Camera game just got more interesting!
That's far from new, and in fact already in use. Ever seen one of these dome cameras that look like a completely black sphere? Yup, that's it.
On the bright side, they won't ever be able to see colors with this.
> Human photoreceptors aren't sensitive to IR. In http://en.wikipedia.org/wiki/Photoreceptor_cell
That's a linear plot and a bit misleading. Since eyes operate over many orders of magnitude of brightness, useful plots are on log graphpaper. Here's one which shows that humans can see far out into IR well past 900nM if the light source is millions of times brighter than the peak at visible green http://amasci.com/graphics/IRcurve_HVS.jpg
So to see through the special plastic, just use a powerful near-IR spotlight, plus IR-passing filter goggles.
It's basically just an IR filter as many people have said.
This isn't new, a lot of surveillance cameras on buses and in shops are mounted inside black domes so you can't see if you're being watched (Or if there's a camera there. Some are fakes, but you can't tell which!)
So here's some trivia about IR:
Humans can see a very small amount of "Near" IR. You can make a Low Pass filter and on a sunny day, see through it. This is a really poor system, but kind of a fun thing to mess with.
You can buy IR webcams from Eyetoy that use IR LEDs to fake 'Night Vision'. this is a lot easier to use if you want to walk around and look at stuff out of curiosity (Or stare through security plastic and look like a crazy person).
Many pigments we use don't show up, they're IR transparent (Hence the looking through clothing aspect). Coca Cola for instance shows up as clear as water. Most t-shirts will show up as plain white unless they're dyed or printed with black ink.
If you think you're being watched by an IR Camera, get your phone out - An Infra Red LED or light will show up as a bright white light though your phone's camera (You can exploit this to look at your remote control flickering and blinking when you press buttons).
You can really annoy the owner of a security/surveillance camera by buying a cheap LED torch, swapping the LED for an IR one and pointing it at the camera. This will not blind it, but until it adjusts it's white balance there's going to be a bit of a white-out.
This is really nothing new. You could buy cameras hidden in tinted plastic kleenex boxes for years. Cameras can be hidden in sprinkler heads, clocks, thermostats, computer speakers, etc. The list really is long.
There is one that that is a camera and microphone on a small keyfob. Records 2 hrs to a microSD. I show it to customers to show what is possible. No card in it until I show them. I always Then I show them how to spot covert cameras.
It is a use of IR filtering. Camera can be spotted rather easily in a dark room. In a lit room, use the right frequency light to find them. All the previous can be looked up on internet if you are curious.
I showed what is possible to wife, and daughter. They are security aware for something suspicious. There are people out there that like to take pictures or otherwise get their jollies. Also, a camera can be used to stage something. Video doesn't lie after all. society is almost trained to except what is claimed to be fresh, didn't record because it would happen...etc.
An example of awareness would be the slat angle in changing room doors come to mind (news story).
People should be aware of what is possible. The trick is not to become unbalanced worrying about it. Not being paparazzi worthy helps.... ;)
I guess I need to start wearing a shirt with a built in web of IR LED emitters that display advertising like the side of the Goodyear blimp (soon to be Zeppelin!). I can put insulting phrases or even advertising on it, and then only these spies would have to see it.
Need 'nother Friday squid post for off-topic stuff!
Its a WSJ op-ed:
"Taking the Cyberattack Threat Seriously" by Barack Obama (wait.. isn't he President??)
I can think of one good use of this technology, and that would be a dome or sphere to cover a visible security camera on a gimbal. This would be an improvement over the current cameras you see in stores and other locations. A thief or other attacker would not be able to know what position the camera is facing unless they have some IR vision equipment. (Try walking into a store with IR night vision goggles and not attracting attention.)
Of course, the potential for abuse is always significant, but that can still happen today with pinhole cameras and one way mirrors.
Interesting. Note that it depends on illumination by natural sunlight, an incadescent lamp, or conceivably an actual flame. (Or, perhaps, a concealed IR lamp.)
The increasingly prevalent fluorescent lamp rarely emits any significant amounts of IR. In fact the most common phosphor mix emits very little light below 630 nm. The cheaper type of white LED has more deep red, but still very little IR.
So as these light sources become more prevalent, these concealment devices will become useful only in daylight.
I wonder if a technology such as this would make an interesting art piece. You get the outside being styles in the black yet viewed with camera's the inside can light up another panarama.
Well this might open a Pandora's box of another kind. I mean, can you develop materials that allow 50-80% of visible light to pass through while looking entirely opaque to the naked eye, at least at a distance of a few meters? Maybe some kind of extremely nano-porous plastic perhaps?
If you could find such materials and they can be made to resemble wood, stone, or roofing materials, and find a reasonable way to concentrate incoming light in a particular area, I'm certain indoor marijuana growers at sunny locations across the industrialized world would be interested. It would cut down on their electricity bills substantially. Even better if the stuff doesn't permit good IR penetration.
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