Damn - now I need to go off-grid as well
Forensics and industry experts have cast doubt on an alleged National Security Agency capability to locate whistle blowers appearing in televised interviews based on how the captured background hum of electrical devices affects energy grids. Divining information from electrified wires is a known technique: Network Frequency …
Not really. I think this story was pushed by someone having shares in Duracell.
The principal problem I have with some of the reporting about the NSA is that some absolutely reeks of psyops involvement. I'm not quite sure why they are aiming to overstate what the NSA can do other than creating some extra fear factor. Well, boohoo, it didn't work for me.
Oh, so the frequency on the secondary (output) might be different than the frequency on the primary (input)? If this slight delta frequency happens, and then remains in place for an extended period, exactly how many total cycles can be stored in the transformer? If you store enough cycles, will it act as a UPS?
Gotta luv it when the so-called experts wheeled out haven't got the slightest clue about how the Universe works.
Nah, even if you do, you're still left with the existential hum
No you wouldn't, not if you're already tapping millions of microphones.
I doubt it's precise... maybe state- or country-level accuracy. Useful for tracking an elusive whistleblower, though.
@JefftPoooh: Umm, no, the variations are transient, caused by large loads switching (e.g. lift motors). These will affect the locations fed by the same substation, but the substation acts as a filter, so little disturbance goes beyond. Therefore the pattern of disturbances will be unique to the substation, but you need a tap there to record it.
It sounds just about feasible, with enough resources, but it would be a lot easier to profile journalists' recording equipment, and follow them around. There's probably less dedicated journalists than substations.
They will track you through the sewer pipes by the colour and content of your sh*t.
Oh, they've been doing that for years. Remember all the alligator in the sewer stories? An alligator can carry a lot of monitoring equipment. It also allowed them to develop a highly-profitable handbag business for additional slush funds.
Yes, the one with the tinfoil hat. No, that's NOT my handbag.
Gotta go with you on psyops, but I suspect it's more innocuous, a factor of poor understanding of what is required to track *global* power fluctuations in manpower alone.
It'd be annoying to just track London, bewildering to track New York city. Incomprehensibly man hours horrific globally. Even for remote monitors to send data on grid fluctuations in a particular area (which would be, by necessity small, due to ground current differentials and assorted other phenomena.
So, I'll go with an ill informed (sparse are those truly informed on the subject) correspondent reporting on "well, I don't know, it *might* be possible".
Hell, with the saturation level required, we'd have a massive payoff in monitoring wind, temperature and humidity and get 100% forecast accuracy.
"They will track you through the sewer pipes by the colour and content of your sh*t"
Have you ever seen fluorescein or similar dye used to track the route of drains when there is some doubt about where they really go? It's quite impressive. Presumably getting the dye into someone's food wouldn't be that difficult.
Half a smiley here.
A box that outputs hum patterns of your choice. These could be fake ones randomly generated, or maybe real ones streamed over the internet from the Taiwanese national grid. Remember folks you heard it here first.
A working UPS (not in stand-by mode) is in effect a 50 Hz randomiser.
That you are paranoid does not mean they are not out to get you.
Surely a notch-filter, to remove everything from 20Hz to 100Hz, would do the job nicely?
No hardware required, no exotic software, it can probably be compelted with open source software (eg Audacity) in a matter of minutes, and would completely strip the recording of any tell-tale signals.
That's okay if you're the one in control of the recording equipment, but the noise randomiser could 'poison' another's covert recording and cause it to fail the non-tampered test.
Or just turn the incoming mains off at the consumer unit and record in natural light using a burner phone...
"...just turn the incoming mains off..."
So how do I do that in my hotel/office/serviced appartment?
Why not *just* set up an anechoic, faraday caged chamber and record straight to wax cylinder with a porcupine quill?
"...notch-filter, to remove everything from 20Hz to 100Hz..."
I'm not sure that a 5:1 band-stop filter qualifies as a "notch".
Nope! The harmonics go way way up through the spectrum. You'd need to get rid of every frequency that's a multiple of 50Hz+/-5%. Up to about 5k. That encompasses virtually the entire speech frequency range.
Not even professional tools can totally remove mains interference without severe artefacts.
are you suggesting that a large electromagnet with an external field coil modulating at 50 Hz is not "common hardware"?
mine's the one with the pacemaker
"Not even professional tools can totally remove mains interference without severe artefacts." maybe, but NSA has also tools you don't know about for this :)
"Not even professional tools can totally remove mains interference without severe artefacts."
But there's no need to remove the traces of mains. IF the situtation arises where it could be removed, don't remove it. As has already been suggested, just swamp it by remixing with the addition of a rather stronger but still plausible signal wandering suitably within the expected frequency range. Add harmonics to taste. No plausible way of identifying the genuine one vs the later addition. Job done, method useless.
That's not a good plan. Just like shinning lasers at aircraft as they are trying to land and squawking on police frequencies, if you start dicking about with frequencies on the national grid you will find you receive a lot of very determined attention very quickly.
Double plus ungood is the fact that you are now the eejit almost certainly with a unique noisy ENF.
If I record all of my videos in the middle of Manhatten,LA, Biejing or Bankkok and they manage to discover this fact will it really make anything any easier......
I have difficulty in understanding just how usefull this really is. The proximity would be so large that it would be unusable.. or is there a factor of detection that I didn't understand.
I think the idea is that they could identify a studio where the recording was made by comparing with previous output from that studio. Might be useful for identifying a pirate music factory, but it would need the interview to have been done in a studio already in their database, or at least that one end of a phone interview was in that studio.
If the interview were done anywhere else, the police (or whoever) would need a database of the electronic signatures of every room in the world. Impractical, as you say, especially as the equipment at any location is likely to be variable - it certainly is where I am sitting at the moment.
Simple- 50Hz- not US. Record away and pile doom upon your enemies!
60Hz Probably US- Take more care- then record away. Pile doom carefully and with plausible deniability upon your enemies!
No, it's worse than that and that's why this is impossible.
The "noise signature" of every studio changes over time. The technique is useful to confirm whether or not a recording was made in one take or whether it's been tampered with, no more, no less.
- Eg if the background hum has "jumps" in it, then a segment was either cut out or cut in. If the background hum is missing, then it's probably been tampered with.
It's listening for frequency shifts as the load changes on the local substation. Those changes are very chaotic, and quite random - the HVAC might be merely chaotic given a known outside temperature range, but the lift movements really are random!
A given florry ballast might whine differently to another, but again, that whine will change as the supply voltage varies and the whine pattern will change as the lamp and ballast ages, and significantly when the lamp is changed.
"the police (or whoever) would need a database of the electronic signatures of every room in the world."
And what, exactly, do you think the NSA has been doing lately; Or don't you watch television?
I call BS (except perhaps in very limited circumstances), just as many did in the comments on the article here in 2010.
battery driven camera's could fix the issue, a very large percentage of recording devices are run off batteries.
any reason for the down vote ?
Just curious if i have stated something daft.
So, sort of like a large scale version of Van Eck phreaking?
Yes, I read Neal Stephenson and that's where I first came across it...I thought it was fictional, but apparently proof of concepts have been done.
Every day is a school day, eh?
You could in theory make a noise interference reference database from freely available media on the likes of You tube producing locations based on available or scraped user data
Another possibility would be to purposefully add noise to lines that could later be decoded and identified.
Some secure buildings and rooms have windows mounted in 'floating frames', much like the glass in a picture frame. A couple of high speed electric motors turning eccentric weights introduce vibration to the windows to thwart laser and IR surveillance equipment. The signal to the motors is sent from transducers analyzing unique, dynamic variables in the buildings HVAC system to introduce randomness that is unique and impossible to replicate, or filter out, outside an incredibly controlled micro-environment. There are simply too many variables in an HVAC system.
Something similar could be done with mains power, and you'd only have to do it where the power came into the building. For the paranoid executive, or Cobra Commander, I suppose there might be a degree of 'Black Sheep' concern. If your building is the only one on the block expressing a palsied utility hum you're going to stick out (like the solitary black sheep in the flock). I would hope, that if someone were outputting a volume of 'undesirable' media sufficient to rule out natural grid fluctuations, that the State agencies already knew where they were. But I've got little faith in those jackasses.
"You could in theory make a noise interference reference database from freely available media on the likes of You tube producing locations based on available or scraped user data"
...Or an audio survey from all of the tracking transceivers (cellular phones).
"The problem was a prodigious one because of the huge amount of frequency variation in local power grids. All manner of electrical devices could cause a dip or spike in neighbouring networks."
Well...yeah: That's what makes it locational data, surely?
I seem to recall an interview on the radio last year where police in the UK were using ENF to locate audio recordings geographically. It's a bit hazy, but I seem to remember that they were building up a database of locales.
If the UK Police were talking about doing it (or even trying to do it) last year, then I have no problem believing the NSA are already doing it and have been for years.
Discourage whistleblowers by saying 'We know where you are , we are coming to get you!'
If they did have a technique that worked , they wouldn't publish the details, because then whistlebowers , or ISIL terrorists making their 'cough up or we kill the kid' videos would very quickly take precautions to avoid their location being identified.
Maybe they can track location, but they aren't going to tell us how they do it.
"Maybe they can track location"
Not really. At any given time, the grid frequency in the UK is the grid frequency *everywhere* on the grid in the UK. There may be local changes in harmonics and stuff in different parts of the network, but the fundamental frequency is location-independent anywhere on the grid.
The 2010 article, iirc, alleges that a database of grid frequency vs time can be used to verify *when* a recording was made, and there is some limited plausibility in that, at least in principle.
On the other hand you cannot easily use mains hum info to verify *where* a recording is made, except perhaps in the presence of obvious standout oddness e.g. spot welding machinery in use 3 metres away.
Otherwise known as FUD. Fear, Uncertainty and Doubt. Standard issue, cheap, easy and always works to some extent. It's a throwaway freeby that comes whenever an argument has to be released against something.
I first learned of the term when I had to participate in a competitive proposal for some US Defence contract. " Where's the FUD ?" (against the competitors' solutions) I was asked.
Standard acronym in the IBM sales force handbook back in the 80s. After a FUD session they usually rolled out "Remember no IT manager ever got fired for choosing to go with IBM." Worked well given their market share, which couldn't be based on superior technology because it wasn't.
"The second problem was the need to log ENF values and the secret signal sauce that allowed location to be determined. "This could mean hundreds or thousands of logging devices in a country if you want to be able to locate a recording accurately," he said."
Not a problem, we are installing those-
"We aim for all homes and small businesses to have smart meters by 2020. Energy suppliers will be required to install smart meters and take all reasonable steps to install them for everybody."
Then there's the Xbox Kinect, Siri's online audio analysis etc etc and Google did some EMF investigations with it's Streetview cars
If they ARE RECORDING and storing ALL telephone conversations and various other communications, they already have various background signals (and probably not just 50 Hz ones).
Makes one wonder if the "Internet of Things" will lead to the oppressive net of beings....
Last thing I need is a lonely (electronically-) promiscuous fridge joining up with others of its kind in some sort of NSA-led refrigerated neural network....puts a chill on things, one might say....
"...the need to log ENF values and the secret signal sauce..."
Is that the one with 11 secret herbs and spices?
Puts 50Hz-proof tinfoil hat on; exits stage left humming...
"recording .. telephones .. they already have various background signals (and probably not just 50 Hz ones)."
Unlikely. There's so little bandwidth/data in a typical highly compressed telephone call these days that it's amazing you can ever understand the caller at the other end at all (though if you turn it into small scale VoIP it suddenly needs hundreds of kbits/s again, but that's another story). The idea that you can then extract useful 50Hz harmonic info from the recorded background is almost infinitely improbable.
Nice hot cup of tea, anyone?
It's the Good Times Virus all over again.
I think it could be done, and quite easily. I think the issue is that they're not telling us the whole story. All you have to do is *inject* noise at the substation level. A known, cyclic pattern that can later be extracted from a recording. Et voila, you'll know which sub-station the recording equipment was getting its power from, and from there you can make a deduction, or, in the case of the Americans, carpet-bomb the entire fucking neighbourhood.
If they're doing it, *that's* how they're doing it.
I don't work for the NSA. Honest.
It's possible that a battery-power device could pick up radiated mains hum from the surroundings, but blocking such interference is part of designing professional recording equipment, things like using a balanced line microphone lead.
But what will your digital recording module do to these very low strength signals that do get through the screening?
It may be that the Police still record on cassette tapes because they know it doesn't lose that background signal. And so they can give a court an assurance. Their recorded evidence can be tested with tests that are known to the court system. But how much does the digital recording technology already used by the news media fit in with those tests?
If I were a future Edward Snowden, I'd be worried more about whether the compressor program had been hacked. Can you trust the companies which make the hardware? Have we already forgotten the Sony BMG copy protection rootkit scandal?
"This could mean hundreds or thousands of logging devices in a country if you want to be able to locate a recording accurately,"
I'll get my tinfoil meter cover
Several USA power companies can get their billing info over the power lines. They use such info to find out where people are illicitly using 'free power', too.
Nothing really new here...
It is from germany
It deals with technology more complex than "Elve shagging knothole"
It bashes on the "Evil Amis"
It appeared in "heute"
=> It is definitly NOT True
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