BAD VIBES: High-speed video camera records your voice from trash Run a camera fast enough and its images can capture sound from the way nearby objects vibrate, according to boffins from MIT, Adobe and Microsoft. The experiments, announced by MIT, worked so well that they claimed to have recovered sound from the leaves of plants, and the vibration of a crisp packet. The latter, as the …
True or not, it's not unheard of, and I'm pretty sure I've heard of a laser being used to detect vibration at some point in the not-too-distant past. If they did, they didn't use a mirror but the glass itself, much like how a shotgun microphone focuses on the acoustic vibrations of the flat window panes.
But here I thought they were trying to recreate the real sounds off old silent cinema (no chance at only 24fps). Silly me...
"The real question is, now that this is public what did the spy agencies just invent that's so much better?"
The sooper dooper pooper scooper. That's the nickname given to a device in an old Piers Anthony novel, IIRC, which can be focused on any point in space and time, allowing the viewer to see what happened at that point. Things like walls, distance, etc are completely irrelevant.
Aha - a quick search reveals it's called Macroscope.
There's an Asimov story that pre-dates the Macroscope by 13 years: The Dead Past, Asimov, where being able to see and hear anything in the past, including only 1 second ago, has devastating implications for everyone's privacy.
(Not that I'm casting aspersions on The Macroscope: I'd not heard of it, and now I want to read it.)
The real question is, now that this is public what did the spy agencies just invent that's so much better?
You mean like some kind of exotic Acoustic Vector Sensor that can record all conversations whispered or shouted within a 25 meters radius ?
http://www.newscientist.com/article/mg21929364.400-matchsticksized-sensor-can-record-your-private-chats.html
Yep , but that requires you to fire a laser at a target such as a window and look at the light coming back . In theory this method has the POTENTIAL , to be able to detect the sound from anything that can be viewed optically without giving away your position by firing a nice big juicy laser which can easily be detected .
"Yep , but that requires you to fire a laser at a target such as a window and look at the light coming back "
Nope. You could equally use a passive reflection too.
The benefit of a laser, or any other bright reflection, is that the modulation is much higher and thus easier to detect. It does not need nearly as much signal processing as the crisp packet mechanism.
The laser also allows you to modulate with a carrier and thus remove unwanted signals.
Using a laser and opto-electronic detector to pick up vibrations from a reflective surface and convert the resulting signal into something you could listen to is pretty basic and could easily be done with no need for any fancy processing. Just some analog electronics.
This is a lot of very complex image processing and I for one am glad that the article did not try to reproduce any of the formulae involved!
I thought that the laser technique required a splitter, sending one ray via the moving surface (window), and then combining them, and looking at the intensity of the combined rays. The phase modulation is thus recovered, but you clearly need some very stable fixings for the laser, the splitter, the combiner, etc. And anyway, every time a lorry goes by everything will move and the wanted signal will be drowned out.
That's one seriously difficult technique.
Or you could just look at the movement of the laser on the surface (providing high enough resolution/lenses).
It's a small movement, but it would have one none the less. http://lifehacker.com/5961503/build-a-laser-microphone-to-eavesdrop-on-conversations-across-the-street
Though using something outside the (normal) visible spectrum is even better.
As Charles says, it was based on the vibration of the window and translating the distance variation caused by vibration. Sometimes you could focus on an item in the room that vibrated, glass lampshades work very well.
There was an interesting bug found in the US embassy in Moscow and to this day nobody knows hw it works!!!
"There was an interesting bug found in the US embassy in Moscow and to this day nobody knows hw it works!!!"
Would that be the one with the tuned microwave cavity with a diaphragm that was vibrated by sound?
I think they did figure it out fairly quickly- after it was discovered, which took years...
Yup, the bug that nobody understood is just a good old urban ledgend.
Maybe the embassy staff would not have known how this works, but anyone that has worked with microwave would.
As Wonkapedia says in http://en.wikipedia.org/wiki/Thing_%28listening_device%29 , the principles of a cavity resonator was well understood and the concept of a modulating a cavity resonator like this was even patented in the US in 1941 - 4 years before the bug was installed.
The infamous wooden eagle bug was "gifted" to the US in 1946 (supposedly carved by schoolchildren), and hung in the US Embassy, in the Ambassador's office, over his desk until 1952, when a bug sweep found it.
The US didn't officially tell the USSR they were onto it for almost a decade after that - I don't know if they had staged conversations in front of it during that time, or if they just stuck it in a basement until they made a stink about it in the UN.
"There was an interesting bug found in the US embassy in Moscow and to this day nobody knows hw it works!!!"
1/2 true.
The device was found in a carved wooden copy of the American seal given as a "gift" by the Russians.
The device was a metal structure with a thin metal membrane on one end.
When "illuminated" by a microwave beam (IIRC) the device's resonant frequency shifted which could be detected. Having no battery it never ran out and only emitted RF when painted by an external source.
It's basically the principle of an RFID tag.
would you be referring to the eagle statue as the "Interesting Bug"?
that worked through RF resonance and harmonics which shifted very slightly with vibration (like sound)
all that was needed was a transmitter (on the right frequency) and a very sensitive receiver close by.
Still took them years to work out how it worked
"Wasn't there a rumour that one of the spy agencies had bugged the other by bouncing a laser off a mirror through a window ?"
It's called a laser Doppler velocimeter. It's been claimed to have been in use since the 1970's.
Wheather or not it's actually worked is another matter....
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"Wasn't there a rumour that one of the spy agencies had bugged the other by bouncing a laser off a mirror through a window ?"
It's easy enough to do/demonstrate and is an extreme use case of the photophone - the window itself is the mirror, not something inside the room (dirty windows reflect more light).
The lesson to take away from the laser trick and the high speed camera trick is "double glazing + heavy multilayer curtains, if you must have windows at all"
The signal processing of the video wasn't in anything like real time: “Processing each video typically took 2 to 3 hours using MATLAB on a machine with two 3.46 GHz processors and 32 GB of RAM”
Without knowing the length of the videos in question that is a useless statistic. If each video was 1 to 2 hours long then that's quite good, if they were around 10 to 15 seconds then there's a lot of work to be done.
Good to see a nicely ambiguous heading from El Reg, there's no way this could ever reconstruct the audio from old silent movies but of course that claim is never made or explicitly implied, the oblique suggestion is plausibly deniable - well done chaps!
Given that the audio sample they were trying to see was "Mary Had a Little Lamb", it would seem to be more the latter length. So not particularly swift.
Still, it's just a matter of a few more iterations of Moore's law and/or better optimization before it becomes reasonably quick.
MATLAB?! I've heard MATLAB referred to as "FORTRAN meets APL in car crash", but my point is that it is useful (very very useful) to prove an algorithm but not as quick as "proper code". (Oh, and it does very pretty graphics for little effort.)
So I wonder what 2 hours would come down to.
As someone posting from a machine with MATLAB on it, the speed of MATLAB varies greatly based on how you're using it. If they're using a lot of MEX code then the speed is semi-realistic. If not, optimised CUDA code would probably bring the processing time down to a minute or two.
"MATLAB?! I've heard MATLAB referred to as "FORTRAN meets APL in car crash", but my point is that it is useful (very very useful) to prove an algorithm but not as quick as "proper code". (Oh, and it does very pretty graphics for little effort.)
So I wonder what 2 hours would come down to."
I think that question came up that Register article about doing software for economics.
IIRC Mathlab Vs C++ came out about 500:1.
so probably custom hardware needed.
> MATLAB?! I've heard MATLAB referred to as "FORTRAN meets APL in car crash",
Yup, but it's not as bad as IDL
> it is useful (very very useful) to prove an algorithm but not as quick as "proper code"
That doesn't stop people using it (or IDL) for production purposes
(IDL is a display language FFS. Asking it to perform complex numerical analysis is madness)
I saw a rather dated sci-fi/spy thriller on cable a few days ago.
Title was 'Eagle Eye', starring Shia LaBeouf and Michelle Monaghan (hot).
Eagle Eye was a super computer with a conscience and among other even more amazing things, did what these university boffins are doing.
Now, that was in a 2008 film ...
I can't imagine what they can do 'now'.
In any case, that this can be done almost scares me sh*tless.
It seems that there's nowhere to hide, man.
"Now, that was in a 2008 film ..."
In the 1968 film "2001" two astronauts shut themselves in a space pod to discuss switching off the AI on the almost sentient spaceship's computer HAL - without it hearing them. Their faces are visible in profile through the pod's window - and HAL reads their lips. Murderous twists and turns then ensue - on both sides.
D-a-a-i-i-i-s-s-s-s-y-y-y-y-y-y-y-y-y-y-y
I think that people were supposed to root for the humans against the machine in the the film Eagle Eye, yet when you look at it the machine was actually trying to defend people from being subjugated by powerful people who were violating the constitution left right and centre.
Ironic.
Ah, good old-fashioned nursery rhymes from my childhood - lovely.
Mary had a little lamb, she couldn't stop it gruntin'.
She took it up the garden path and kicked it's little **** in.
Mary had a bicycle and she rode it on the grass*,
Every time the wheel went round a spoke when up her arse.
Now when Mary rides her bike, she rides it back to front.
'Coz <you can work this line out for yourself>
*grass as in 'parse', not as in 'mass'
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The countermeasure to eavesdropping from vibrating windows is to pipe music through the window frames. This process defeats that countermeasure, if (and only if) you can observe the object normally (i.e. at *exactly* 90 degrees to the glass) through the glass, so that distortion caused by refraction isn't an issue.
My next suggestion would be to combine the musical window frames with double-glazing where the two panes are not quite parallel to one another, so it's literally impossible to see through from any angle without some refractive distortion.
Where do I collect my fee?
I had to laugh at the idea that a CCTV camera will ever be able to eavesdrop on you. Yes it may be technically possible, but if you look at all the CCTV footage available on the internet, even if the person was holding up a placard with what they're saying printed like in the cartoons, it'd still be an unreadable blurry mess.
"The pretty blue and green blinking lights on your routers, switches and computer monitors emitting electromagnetic frequencies tell us some interesting things too."
No need for LEDs, the monitor cable gives off sufficient EM to read the screen remotely if you're clever about it. El Reg reported this years ago.
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