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Smart Meters Reveal What You're Watching
xororand writes "H-Online reports that 'researchers at the Münster University of Applied Sciences have discovered that it is possible to use electricity usage data from smart electricity meters to determine which programmes consumers are watching on a standard TV set. By analysing electricity consumption patterns, it is, in principle, also possible to identify films played from a DVD or other source.' It's time for some clever EEs to come up with a countermeasure. Unfortunately alumfoil hats have already been dismissed."
I'm guessing if you built a plugin AC device that just sort of created random draws on your electrical supply, say ten times a minute, for random durations, I imagine that would pretty much kill any leak of such information.
The world's burning. Moped Jesus spotted on I50. Details at 11.
Light and dark passages in these films, large volumes of data, and a minimum of interference from other devices are the key to performing this analysis.
turn on a motor that draws at least 0.5A and you should be safe from those boxes....
Jehovah be praised, Oracle was not selected
More reason to ban their implementation!
Power companies should NEVER be allowed to gain knowledge about, nevermind make a profit from my porn viewing habits!
Dang. Y'all'd think they had a differnt word fer everthang over thar.
Why do it like this when the cable box can report a lot more info about what you are viewing and does not need new hardware to pull it off.
And what if the TV, STB and various players are connected via a battery backup?
In the cryptography world, this is known as a sidechannel attack - specifically DPA.
"It's time for some clever EEs to come up with a countermeasure."
There are plenty of countermeasures for DPA in the crypto world - However:
1) The negative impact of this is a hell of a lot lower than key extraction
2) The positive effects of having power consumption tied to scene brightness are significant. Localized backlight dimming means that a scene with low average brightness uses less power. OLED displays take this to another level - black pixels use no power.
Also - In this case it appears they were only able to identify which channel a TV was tuned into. DVR makes this MUCH more difficult because fast-forward/rewind vastly increases the number of datasets you need to compare against. Also, while in theory you could identify a DVD, the selection of possible DVDs is so great and the amount of noise in the measurements is such that you're never in practice going to be able to identify someone's watched content reliably.
retrorocket.o not found, launch anyway?
Of course, the reason a DVR negates this is that they draw a huge amount of electricity even when you are not watching the show. They are the biggest single draw of electricity most people have. Incredibly wasteful, but so addictive.
That is because current versions always need to be "on" if you want to record something when you are not around to turn it on.
Supposedly, new versions will be able to go into 'sleep' mode until their internal clock says it is time to wake up.
excitingthingstodo.blogspot.com
And using a UPS should easily defeat this. Move along, nothing to see here.
"But this one goes to 11!"
wait for it....
TV watch YOU!
This sig is not paradoxical or ironic.
According to page 6 of the referenced paper on Van_Eck_phreaking applied to lcd, it does not works on hdcp. A win for DRM, who would have thought.
Jehovah be praised, Oracle was not selected
A similar effect can be achieved by analysis of photon leakage through amorphous silica, aka looking through your living room window.
.sig withheld by request
simultaneously running an identical device with an inverted signal? Now may I please have my daily allotment of tinfoil? Yummy!
Well, for starters, I'm assuming the cable company wouldn't want to be sharing its data with the electric company. Second, this is useful for anyone who doesn't have a cablebox. Cablecards installed into a TV, PC, or anything other than a cablebox are inherently one-way devices. The current spec has no mechanism for them to do 2-way communication (unless it's a SDV system that requires a tuning adapter). The same is true for the little DTA devices and QAM tuners.
They say that "a minimum of interference from other devices". Right, except my electricity meter is for my house, and it has many other devices. So unless you think I'm going to turn off all my lights, my computers, unplug my fridge, shut off my A/C, and so on when I watch a movie, then I can't see this working.
Also there's the fact that light vs dark really doesn't have much difference in terms of power draw on an LCD. Yes there is a bit used to change the crystals, but not nearly as much as the backlight. Then to that you add maybe a receiver, drawing power to do sound and so on.
I could see this perhaps working if you had a meter right on the feed to the TV, but on the whole house? Good luck getting useful data when the A/C is running, drawing 30 amps.
Countermeasures already exist. They're called capacitors.
https://www.eff.org/https-everywhere
Anybody who can hack into the communications link (already published -- easy to crack) can tell if you are home or not. Ideal for someone wanting to break in. Also, a working husband can easily track a stay-at-home (maybe) wife's activity.
I will create a sig when innovation restarts in the U.S.
The feds can just ask the cable companies what you are watching. They'll cave.
I think the key in the article is "standard TV set" by which they mean a CRT. A CRT varies its HT current draw by scene brightness, and its quite visibly obvious when troubleshooting. Heck even a cheapie consumer grade wattmeter could probably detect it. On /. a CRT is probably not considered a "standard TV" anymore, but out in the real world, deployed CRTs on the ground showing shiney pictures probably still outnumber all other deployed and working technologies, at least for a few more years...
On the other hand, the florescent backlight in my piece of junk basement LCD TV is constant power draw, no matter if the LCD pixels let light thru or not. The LCD pixels themselves draw about the same no matter scene brightness. Anyone who's ever done anything with embedded systems knows this... the LCD display itself is usually rated around a milliamp, most of which is wasted in the control ckts, and the backlight usually draws a good fraction of an amp. Even allowing for much higher current draw for fast moving scenes and higher contrast, I'm betting the backlight still wins for power draw.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Have two TVs on at the same time viewing different programs.
Sorry, but gray text on gray background is making my eyes bleed.
Plenty of modern LCD displays use dynamic back-lighting to improve contrast and low light detail.
From wikipedia: "Since the total amount of light reaching the viewer is a combination of the backlighting and shuttering, modern sets can use "dynamic backlighting" to improve the contrast ratio and shadow detail. If a particular area of the screen is dark, a conventional set will have to set its shutters close to opaque to cut down the light. However, if the backlighting is reduced by half in that area, the shuttering can be reduced by half, and the number of available shuttering levels in the sub-pixels doubles."
They still don't get it. TV on != watching. I know a hell of a lot of people who just have it on to have background noise but are paying exactly zero attention to the television.
Seven puppies were harmed during the making of this post.
I've never connected my DirecTV to a phone line or to the Internet because of this.
The set complains every so often :} and no I've never ordered any on demand program or PPV.
It is indeed possible if you have a constant or recurring draw from other sinks (like resistive lights, capacitive motors etc.) but I guess if you have even one of those malfunctioning with a random draw (such as an off-center aquarium pump or an AC unit) or you add signals (like X10 or Ethernet-over-Powerline) that this kind of 'attack' is quickly trumped unless you can get right at the circuit where the TV is on. For that matter, I think an optical attack would be much more reliable (where you measure the light output reflection through someone's windows as they watch TV) but then you might just be find that a spy cam and/or a telelens is much more reliable. If you have those CableCo DVR boxes, they can also be queried remotely.
Custom electronics and digital signage for your business: www.evcircuits.com
See when you open your refrigerator, when your heating kicks in even if it is gas driven due to the start pulse. Every electricity consumption can be monitored and it can be interpreted allowing to see when you get up, what your behavior is (at home). That's why we need data security. No company should be allowed to use these data other than to control electricity production.
This is not as simple as some people think to block. A simple random load added to the mains signal will not do it.
In order to find out if you're watching a given TV program - first you take the TV program, and measure every 5 second periods average brightness..
This gives you 720 samples for an hour.
Now, you load up 720 5 second samples from the targets electricity meter.
You subtract the average value from each of these, so they're symmetrical about 0.
Now, you go through the list, multiplying the first brightness by the first measured energy use, and add this to a total. Repeat this 720 times.
Now, you have the correlation of the power with the TV program.
This is _MUCH_LARGER_ than the correlation of any single time period, and any noise or random non-correlated signal such as fridges or freezers drops out to a large degree.
Random signals have to be of the order of sqrt(720) - 36 times larger than the signal to mask it.
(It's not quite this bad, as there will be some false correlation, epecially given there will be millions of candidate programs, and 5s offsets that can occur)
And yes, LCDs, especially LCDs with newer variable power 'energy saving' backlights that dim or brighten along with the program content to optimise contrast and power use will work for this just fine.
If you read carefully that - it says only if the HDCP signal goes all the way to the display. It doesn't.
Inside the monitor, the cable from the mainboard of the monitor to the LCD screen contains an unencrypted LVDS signal still, which can be snooped.
First you are not going to get second by second readings from your standard L&G or Itron meter. The back haul doesn't have the bandwidth and even if you had a second broadband ESI (energy service interface) in your home there are a few technical hurdles preventing 1 second granularity (2.5 seconds is the fastest that I've seen and not sustained).
However these meters also report the phase difference between the Voltage and the Current. Using this information you can filter out pool pumps, air conditioners, furnace fan etc. As you learn more about what is on in a persons home it does become easier to figure out how an individual appliance is working.
There are a large number of privacy concerns that need to be addressed with Smart Metering. We should probably solve them before some companies start using your personal electricity consumption as a revenue stream
FTFA: "Light and dark passages in these films, large volumes of data, and a minimum of interference from other devices are the key to performing this analysis."
My smartmeter reports hourly total usage, not "large volumes of data"...
Well unless I am mistaken the smart meter does not know what outlet you are plunged into, as the breaker is the only thing that knows that and that is normally inside and owned by the building owner.
And multiple things running at the same time for the most part is useless as everyone always has multiple things running at the same time. the basic idea here is that most things have a ~ constant voltage while a TV varies a lot and it is the change in voltage that matters and corresponds to a particular show.
And yes you have lights turning on a off, heaters and coolers doing the same, ovens heating up and then just maintain temp but thoes are all big jumps that last for at least minutes, TVs very at every frame.
Troll is not a replacement for I disagree.
you are right, they could probably filter the hdcp signal and tune to the unencrypted LVDS.
Jehovah be praised, Oracle was not selected
I can camouflage my grow op simply by modulating the lights using a photocell aimed at a TV tuned 24/7 to Fox News!
Set your phasers on "funky"!
To add to the other commenter, cableboxes are mostly one-way devices as well. They keep trying to implement 2-way communications, but even if the box is capable the cable company I work for does not implement this. Video engineers are a dying breed because they don't want to learn about things like 2-way communication and packet switching. I can guarantee that once the network engineers have their way and video is just another packet service, the pipes will be cleaner, your digital feed will be much smoother, and Nielson will be dead as a doorknob.
There is no way they can tell what someone is watching on their TV by looking at electric consumption. There are too way many variables involved to make this even plausible.
I'd like to see some proof, in English.
I work for a large utility that is currently implementing an AMI system. I can tell you from first hand knowledge that no utility gets (or wants) usage data from its customers every 2 seconds. At my utility we collect usage in 1 hour bins for residential customers and 15 minute bins for commercial and industrial customers. The amount of database storage we would need to collect 2 second interval data from all of our customers would be staggering. As it is we've had to invest in a large server farm to handle the data we are getting.
If I had to guess I'd say that the 2 second intervals are for in-home monitoring using a ZigBee HAN, or something similar (the EasyMeter website is in German and does not appear to have much technical info).
If we did not have DVRs and 500 channels, this would be a lot easier :)
I was told that I "had to connect my receiver to the phone or internet for correct operation". I said I have kids, I will not honor any PPV purchases. They dropped the issue.
whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
Because that idea spoils the whole "smart meters are evil and are corrupting our vital bodily fluids" theory.
I can negate the need for the tinfoil hat with a small amount of authority, my current company builds smart meters, mostly for the US market and the software
to run many of them (not naming names but if you really want to know look up cell based meters, should find us) and the simple fact is that with that type
of meter the power profile lacks the resolution for such snooping, the most often I have seen the usage profile read is once an hour, and that (probably) is
not enough info to do what they are doing. (H-online is down for me as I write this, I will try again later to read it) In the type of meter's I see such detailed
information is just that, too detailed. A 2mb a month data plan is the typical provisioning and the meters generally use half that in a given month.
Note wireless mesh meters may be another story, at least in some deployments, however the only such network like that I have any direct experience with
uses a cell based relay station to phone home with and again doesn't seem to send enough data for such evil observations to be made.
End result? You could do it, but real life smart meter systems have one giant consideration that stops this from working, cost effectiveness, power companies
don't want to pay for data, that just want to know how much of your money to take.
Why do power supplies need 14 lines to my motherboard?
Only 6 for the various voltages.
As far as other posters. mentioning plugging in other devices... they'd have to have random current incoming. The only thing that would work is a UPS which only charges on intervals. Which is basically a laptop power supply...
Light and dark passages in these films,
An LCD set with fluorescent lamp backlights doesn't use more or less power for light or dark scenes. The lamps run at a constant intensity and the LCD shutters (requiring a minute amount of power compared to the backlight) regulates the light passing through.
Its possible that a plasma or old CRT TV set power consumption might vary with picture output. But I'd expect the sound to be as much a factor as the picture.
Have gnu, will travel.
Analyzing the advertising times against the water consumption - and we've got it.
Of course we're assuming
a) everyone flushes
b) everyone uses the toilet for their "private time", rather than the nearest bush or garden ornament
"The greatest lesson in life is to know that even fools are right sometimes" - Winston Churchill
http://en.wikipedia.org/wiki/Smart_meter
Smart meters just talk to the utility company more often. It is still a single point of reading because that's all they care about. The power company doesn't give a shit what I spend my power on, they just need to know how much so they can charge me for it. Not only would they have trouble getting people to agree to monitors on every outlet, but there's no way they'd want to bear the cost, or the insurance issues. They want a single point of demarcation past which nothing is their problem, and that is the meter. They just want meters that can read automatically, and more often.
That, and it's only a matter of time before LED/OLED screens reach cost-parity with LCD and supplant them anyway. Old-skool LCDs with fixed backlights are a dying breed.
Caveat Emptor is not a business model.
I've been waiting for myself to get enough free time to show *exactly this*. The vast majority of TVs - basically everything except LCDs without any kind of "dynamic contrast" feature - have current consumption that is dependent on screen brightness. A Google or similar statistical hivemind could potentially tease out the shows being displayed on a screen in a 'normal' house (not only contrived lab setup) because most household power consumption either switches on much larger timescales than scene-brightness transitions (most don't flick their light switches every few seconds) or else have a repeatable current profile (dish / clothes washer and other appliances). These repeatable light + appliance patterns could be used similarly to estimate when you are home and how many guests you are housing (via how often the dish/laundry runs).
An old electronic technician's trick got me started on the idea - when repairing blown gadgets, you wire an ordinary lightbulb socket in series with the outlet you plug the gadget into. Start with a low-wattage e.g. 40W fridge bulb, and move up as needed. The bulb acts as a current limiter in case there are any remaining faults, and gives you a visual indication of the gadget's instantaneous current, with various 'normal' and fault conditions producing a distinct visual pattern (e.g. "solid on" at plug-in usually indicates a dead short across the HOT / main switching transistor). When doing this with a CRT set (haven't tried it with others), the bulb brightness does directly and eerily track the average scene brightness.
Caveat Emptor is not a business model.
True, but a second TV on the same meter will.
Get half a dozen digital timers and put them on random mode with small devices.
Better yet invent a device that randomly rotates power usage from small spikes to big appliance spikes.
It the end it costs the owner money to run to make bad data.
Their rather emphatic about it aren't they. One installer was so serious about it
I plugged in the phone line until he left . Another installer was at a total loss
when I mentioned I only had a cell phone.
I've had DirecTV for over ten years now and I've never had it connected to a phone line
(Ok, that once but it was new) as the years progressed they have become more relaxed about it.
This new SWM system they have takes up some serious space just to communicate via the Internet.
Once the installer left it was gone. It cleaned up nicely and gave me back an AC outlet.
I have nothing but good things to say about DirecTV, I just don't let them know I like the History channel.
Unless each channel uses a different amount of energy, there is no way in hell they can determine who's watching what show from the power meter.
OK, I'll admit I didn't RTFA, but give me a fucking break. With 500+ channels, there is no way in hell they can figure out who's watching what especially during prime time. It's called prime time because it's the time of day 99.9% of the TV watching public is watching TV. Also, who's to say that power drain isn't a computer, fan, or even a few incandescent lights?
--- Keep the choice with the user..
What about contacting some advertising company interested in consumers' TV habits. I suppose they would easily pay you enough to upgrade your farm and score some return...
A second TV is merely noise, from the perspective of the program you're checking.
You simply get two results out, not one.
Since most people get their TV from a digital service like cable with a set top box or U-verse or FIOS, "they" can just check what their servers streamed to you, or hav ethe local device report back.
Why would they go through easily defeatable shenanigans with power draw analysis to do the same thing?
The whole purpose of metering is to track usage of power whose price varies with time. One could thus install an energy storage device such as a flywheel that stores energy during cheap times and releases energy during expensive times. The client would by necessity need to track their own energy usage to make such a system work using a monitoring device downstream from the storage device which would itself be downstream from the utility company's monitoring device. The storage device could thus be used to smooth out energy drawn from the energy company. During cheap times, the storage device would store extra energy during periods of low load (when viewing the "dark" moments of a movie, for example). During expensive times, the storage device would release extra energy during periods of high load, e.g. when viewing the bright moments of a movie. The client benefits by having privacy, by having a backup power supply in case of outages, and by switching to lower cost power. The power company benefits by needing to supply less power at times of peak demand, and by having a more balanced load overall.
"I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show