Laptops And Flat Panels Now Vulnerable to Van Eck Methods

An anonymous reader writes "Using radio to eavesdrop on CRTs has been around since the 80s, but Cambridge University researchers have now shown that laptops and flat-panel displays are vulnerable too. Using basic radio equipment and an FPGA board totaling less than $2,000 it was possible for researchers to read text from a laptop three offices away. 'Kuhn also mentioned that one laptop was vulnerable because it had metal hinges that carried the signal of the display cable. I asked if you could alter a device to make it easier to spy on. "There are a lot of innocuous modifications you can make to maximize the chance of getting a good signal," he told me. For example, adding small pieces of wire or cable to a display could make a big difference.'"

Telling question

[Tumbleweed (3706)]

"I asked if you could alter a device to make it easier to spy on."

Okay, see, that's the type of questions the NSA likes to see its potential employees ask. Any other type of person would ask if you could alter a device to make it *harder* to spy on.

Re:Telling question

[by Anonymous Coward]

Unless, of course, you're looking to protect yourself from such modifications.

less social intelligence than a 13 year old

[circletimessquare (444983)]

"i have a friend, ehem, who is worried about this kind of hack, ehem, and i was, i mean he was, wondering what he could do to..."

"guard against it?"

"no, no, what he could do to... um, make sure the 'bad guys' haven't modified his system, ehem, like, what would a bad guy do to make this work better so he could do it, i mean, so he could have an idea of the kind of modifications to look out for?"

Re:

[mikael (484)]

"i have a friend, ehem, who is worried about this kind of hack, ehem, and i was, i mean he was, wondering what he could do to guard against it?"

Sit inside a Faraday cage ...

but make sure you always carry a spare key for the door with you

BEHOLD ! I am TEMPEST, they LORD and MASTER

[by Anonymous Coward]

BEHOLD ! I am TEMPEST, thy LORD and MASTER ! Bow before ME ! Fear ME ! I see ALL*!

*its a bit fuzzy, like snowy tv - BUT I SEE ALL !! FEAR ME !!!

Re:

[Tackhead (54550)]

> BEHOLD ! I am TEMPEST, thy LORD and MASTER ! Bow before ME ! Fear ME ! I see ALL*!
>
> *its a bit fuzzy, like snowy tv - BUT I SEE ALL !! FEAR ME !!!

Hey, you, get back in that teapot!

I met a man upon a stair,
A little man who wasn't there,
He's reading all our screens today,
I think he works for NSA!

Re:Telling question

[goombah99 (560566)]

Well the voting machine companies would like to know how to do that too.

Re:Telling question

[Detritus (11846)]

The NSA cares about both questions. They have a large group of people dedicated to keeping government communications secure, and another large group of people dedicated to hacking everyone else's communications systems.

Re:Telling question

[Tumbleweed (3706)]

Good point, Agent 11846.

Re:

[AusIV (950840)]

I've got some friends who are prospective NSA employees, and while I'm sure this is something the NSA would like to hear them ask, the NSA also likes their prospectives to keep a low profile. Reporting for a technical website and asking questions like that hardly keeps a low profile.

ch0wned!

[by Anonymous Coward]

I think this means they've always been vulnerable, but no one knew. It's not like someone turned on the Vulnerable switch.

Re:ch0wned!

[LiquidCoooled (634315)]

I wonder if this could be used (at close range to reduce errors) for the only remaining analog hole

The MPAA will be furious!

Re:

[DragonWriter (970822)]

I think this means they've always been vulnerable, but no one knew.

Or, rather, no one publicly announced it.

I doubt if the NSA, for instance, had discovered this vulnerability years ago, they would have trumpeted it publicly.

Re:

[Lehk228 (705449)]

actually the NSA is pretty good about disclosing vulnerabilities such as that. the threat of foreign corporate and military espionage is much greater than the usefullness of such technology for domestic abuses.

Oh bull

[by Anonymous Coward]

No one knew? That's utter nonsense. I noticed that my laptop lcd monitor would cause interferce at times on my FM radio seven years ago, depending on what it was doing, and what station I was listening to.

That's a pretty big red flag that these suckers were subject to Van Eck.

And if the NSA could hear Scott McNealy's friggin keyboard outside in the parking lot (as they later told him during a meeting in the late 1990's), you'd better believe that the NSA has had LCD monitor reading capability for at least that long.

Just because it's not in the popular press, or published papers, hardly means that no one knew. The only thing surprising here is that it took so long for someone to get a paper out it.

I don't mean to disparage the researchers, who deserve a lot of credit to finally bringing this to public knowledge, but this is really low-hanging fruit.

Yes, we've known for a decade

[billstewart (78916)]

... i.e. just about as long as laptops have been usable. Wireless eavesdropping and TEMPEST issues were a common discussion topic back in the Cypherpunks era, among the technical experts as well as among the tinfoil hat crowd, and a number of us had worked with TEMPEST professionally.

My ~1995 laptop (486? Pentium 60? MHz) would display on my parents' TV screen when I visited them. (No, I didn't live in their basement, I'd just avoided having a TV in my house back then:-) It wasn't in sync, so there were three partial screen images scrolling slowly, and there weren't enough pixels, but it was readable enough to be obvious that a real receiver would be able to display the output cleanly. My guess was that the culprit wasn't really the LCD drivers, but the auxiliary VGA port on the back of the laptop; I no longer remember if I tried turning that on and off, or exactly which laptop model it was, but Google probably knows.

The real difficulties are getting enough focus to only grab signals from the laptop you're looking for, and not all the other CRTs and TVs and LCDs around, which is why you're reading an interview with an expert like Markus Kuhn and not just some 1337 k1dd13z, and doing so without parking a big antennaful van on the street in front of your target.

If you look at the real security threats here, there are two sides -

• Crackers trolling for whatever they can find, like passwords and credit card numbers they can abuse, who are willing to eavesdrop on anybody nearby, such as people in an airport
• Cops and spooks and secret police who are targeting *you*, in which case you've got much more serious security problems than whether your laptop screen can be eavesdropped.

An ounce of prevention

[L. VeGas (580015)]

adding small pieces of wire or cable to a display could make a big difference

That's why I always carefully remove all the wires from all my electronics.

Re:An ounce of prevention

[Hoi Polloi (522990)]

I keep my laptop under my tinfoil hat. Problem solved.

Wow

[Shadowlore (10860)]

For example, adding small pieces of wire or cable to a display could make a big difference.'"

So adding an antenna makes it broadcast better meaning you can pick it up easier. Shocking. Very useful for remote spying. Step one, add an antenna to the target's display.

Re:

[pclminion (145572)]

If you're non-technical, and you see a little piece of wire hanging from your display, I don't think your first thought will be "Gosh, that looks like an antenna!"

The Offical Howto

[pak9rabid (1011935)]

Step one, cut a hole in a box Step two, put your antenna in that box Step three, make her open the box Whoops, scratch that last step

HDMI?

[jandrese (485)]

I wonder if they're just reading the signals that are being sent over the wire? With analog signals this is pretty easy to to, but with DVI it's a lot harder, and way harder still if the signal is encrypted. With the future of display technologies appearing to be heading as close as possible to encryption to the eyeballs, it makes me wonder how long this will remain viable.

Re:HDMI?

[drinkypoo (153816)]

wonder if they're just reading the signals that are being sent over the wire? With analog signals this is pretty easy to to, but with DVI it's a lot harder, and way harder still if the signal is encrypted.

With DVI it's probably a lot harder, but the signal might actually be clearer if you knew how to pick it up, kind of like how you can pick up UWB radio at high ranges. The on-off style of the signal creates a sharper signal. It might require more hardware but I wouldn't be surprised if you could do it at longer range.

An encrypted signal, of course, will be much harder to deal with whether there's an easy-to-receive digital signal or not.

I'm skeptical of the idea that the main video link will be encrypted any time soon though, because of the immense bandwidth involved.

Also, I have to wonder if you could simply pick up the signal between the controller, which decodes the signal (digital or no) and the panel itself...

Re:

[chgros (690878)]

I'm skeptical of the idea that the main video link will be encrypted any time soon though, because of the immense bandwidth involved.
I thought that was already done.

http://en.wikipedia.org/wiki/HDCP [wikipedia.org]

Re:

[pushing-robot (1037830)]

If they were able to read a signal from a laptop, they were reading a digital signal. Laptops have always used a digital display interface.

But yeah, encrypted HDMI would make it more difficult.

Re:

[LordSnooty (853791)]

So now there's a good reason to stop encryption to the eyeballs, it'll help the terrierists...

Bad story submission title

[drinkypoo (153816)]

The title given to this story on slashdot is awful, especially for a geek news site. Haven't we already established that obscurity is not security? And about a million times over?

An unpublished vulnerability is no less real than one that has been announced, and is in fact more dangerous because the lack of an announcement leads to a false feeling of security. The real story is that your laptop has in fact been vulnerable to van eck phreaking for years and year, not just "now".

It's a good thing I haven't had faith in slashdot for a long time now, or I'd be really disappointed. As it is, I'm just pointing this out for those who didn't already notice.

Bypassing DRM

[harry666t (1062422)]

Maybe this technique could be used to bypass that DRM stuff and capture movies etc right from the screen, how do you think about it?

Security hole in the making

[Nonillion (266505)]

I remember seeing a demo of this back in the 80's. I always had a suspicion this was possible, however some people still balk at this as 'science fiction'. I can assure you it's not. It's this kind of thing that should be waking up manufactures to the perils of shitty RFI design. Spewing broad band spectrum pollution not only causes radio interference, but also opens you to security problems.

Not to go slightly off topic here, but BPL (broadband over power wires) providers ought to see this as a wakeup call. Coupling broad band ODMF signals on widely spaced wires hanging 40+ feet in the air, radiating like antennas is a HUGE security issue. Not only can BPL be jammed with something as simple as a CB or Amateur radio transceiver, but a creative individual could use similar methods to monitor BPL signals.

Re:

[drinkypoo (153816)]

Not only can BPL be jammed with something as simple as a CB or Amateur radio transceiver

Really? I could have sworn you'd need a transmitter.

but a creative individual could use similar methods to monitor BPL signals.

Not only do you already have to worry about any signal broadcast over the internet, but the fact that it's sent over a big long wire (as you describe) means it's even more important to use encryption. And what do you know? Any sensitive communications I perform over the internet are already en

Alert: my eyes are malfunctioning

[drinkypoo (153816)]

Parent line, then my reply, appears below:

Not only can BPL be jammed with something as simple as a CB or Amateur radio transceiver

Really? I could have sworn you'd need a transmitter.

I read that no less than three times and still believed that it said "receiver".

I apologize for this part of my comment.

Looks like my eyes are failing me, guess I'll go home (for those wondering, yes, I do come in pretty early.)

Re:

[Nonillion (266505)]

'Not only can BPL be jammed with something as simple as a CB or Amateur radio transceiver
Really? I could have sworn you'd need a transmitter.'

A 'transceiver' is a combination transmitter receiver. During some BPL tests BPL signals were completely interrupted by a 5 watt signal on the 40 meter (14MHz) band.

'but a creative individual could use similar methods to monitor BPL signals.
Not only do you already have to worry about any signal broadcast over the internet, but the fact that it's sent over a big long w

Re:

[chochos (700687)]

you've gone way off topic IMHO... people spying on your screen is pretty bad. But this does not make BPL a bad thing... protocols like SSL allow you to transfer information over TCP securely, regardless of the physical medium. If it works on wireless, it works on BPL, right?

Re:

[DragonWriter (970822)]

Not to go slightly off topic here, but BPL (broadband over power wires) providers ought to see this as a wakeup call.

Broadband providers aren't, I would imagine, particularly concerned about their user's privacy. If they see it as a wakeup call, it'll be a wakeup call to lobby the government to institute regulations favoring BPL because it is easier to monitor for law enforcement and security purposes, and to impose new barriers on broadband systems less easy to monitor.

van Eck only made it public

[michaelmalak (91262)]

Russia and the U.S. had been snooping VDT images since the early 1970's or earlier. van Eck just made it public by publishing a paper on how to do it with $100 of Radio Shack parts. cryptome.org [cryptome.org] forum postings include a reference to a 1973 book.

Cryptonomicon?

[chochos (700687)]

So the hack that is mentioned in Cryptonomicon is pure sci-fi? It says that van-eck was possible on a laptop because of some backwards compatibility issue, in which laptops still refreshed the display 60 times per second or so, even if they didn't need to, so you could pick up on that radiation or something for the phreaking. It wasn't really possible until now? Or is this a different method where you can spy on LCD's using some method specific to LCD's?

Re:

[v3lut (123906)]

I don't mean to alarm you... But Cryptonomicon was, in fact, entirely sci-fi.

Either that, or the vulnerability was because the guy was running Finux. As long as you don't install that you should be fine.

TEMPEST in a teacup

[by Anonymous Coward]

Long before Van Eck publicly demonstrated it, the NSA was well aware of the problem. It extends beyond the CRT. NSA created the TEMPEST program to reduce radiation of information.

Simply put, change the voltage level or current level of a device and you generate a signal that is conducted along wires and other conductive paths and radiated from those conductive paths. Interception of the conducted or radiated changes can be used to re-create
the original information. Wether the information is in serial, paralell or raster format it is a relatively trivial problem given some time and computing resources.

Is it a problem for most of us? Given that someone will try the easiest ways to get the information, using Van Eck or other types of TEMPEST
attacks is much less likely than social engineering or other means to get your information.

Wobbly windows to the rescue!

[HerrEkberg (971000)]

So this is what all those fancy 3D desktops are good for. Just set wobbliness and fuzzy effects to max and no one will be able to make sense of what is going on on your screen (including you - trust no one).

At last!

[ThanatosMinor (1046978)]

I can spend $2000 to be able to read my laptop that's across the room while I'm still in bed. Now all I need is some sort of glove I can hook up to a robotic arm so it can type for me. Or better yet, I can invent a fing-longer!

Sigh If only they would make a portable version of my laptop...

TEMPEST

[Detritus (11846)]

The NSA, and other intelligence agencies, have been exploiting stuff like this for more than fifty years. Technology changes, but the fundamental principle, interception of EM radiation stays the same. You can even spy on certain models of electric typewriters. If you ever get the chance to look at TEMPEST certified hardware, you will see the lengths that the engineers have to go to, to shield and filter an electronics device. Besides the box itself, all cables have to be well shielded and filtered, or they just function as antennas for your sensitive data.

DMCA

[ChrisMaple (607946)]

LCDs and plasma have been favored by DMCA people as a way to beat the analog hole. Here's another nail in that coffin.

Not too surprising

[mobby_6kl (668092)]

This shouldn't be too surprising to anyone who's tried listening to audio output from a typical laptop. You can hear everything, including processor load, disk access, mouse or window movements (the sound noticeably changes depending on the cursor, hovering over a text area sounds differently than over the desktop or window resize areas) and typing. I'm sure some of that audio noise also escapes as electromagnetic emission which, can be picked up with appropriate equipment.

I'm not an expert on Van Eck phreaking, so it's possible that the previously used methods were incapable of detecting this for whatever reason, but the presence of these emissions and the possibility of spying shouldn't be surprising.

This reminds me of the scheduled tinfoil supplies delivery I need to take care of...

Re:

[Ungrounded Lightning (62228)]

I'm not an expert on Van Eck phreaking, so it's possible that the previously used methods were incapable of detecting this for whatever reason...

Previous methods could intercept the signal. Processing it back into an image was the problem.

CRTs essentially modulate the beam current with the basic video signal. Leakage of that puts into the air precicely what you need to produce a copy of the image part (though the current is cut off for retrace). Also pick up and sort out the spikes from the H and V defle

Article Polls!

[mobby_6kl (668092)]

Holy shit, I just now noticed that this article has its own poll, how awesome is that!

My first reaction was "WTF did the relatively recent end-of-civ poll go" and then when I voted it showed this article's comment under the poll results, which was another WTF moment. When was this feature added/first used? I can already see great use for the article polls, for example the editors could try to guess the popular tags and use them for poll items.

• Yes
  
• No
  
• Hellno
  
• Its
  
• Chairthrowing
  
• CowboyNeal
  

Work done three years ago

[Tom Womack (8005)]

This really isn't new news; the work was done in 2004 and presented as

http://www.cl.cam.ac.uk/~mgk25/pet2004-fpd.pdf [cam.ac.uk]

as well as countermeasures; randomising the low-order bit of all your pixels anew in every frame would be ideal, but using colours which have the same number of bit transitions in 'black' and 'white' works almost as well. Looks a bit ugly to have your screen entirely in off-greens and off-pinks, but that's the price of security.

HDCP actually helps against this kind of thing, because there are no long lengths of wire carrying unencoded video signal.

Re:

[TodMinuit (1026042)]

Wouldn't it be easier to apply countermeasures to prevent eavesdropping to an entire room instead of individual pieces of hardware?

Odd thing...

[Ant P. (974313)]

I was messing around with an AM radio near my PC just 2 hours ago trying to get a useful signal. I noticed something funny going on - every time I moved the mouse making its LED light up, the radio got a strong buzzing noise until the LED powered down again. It's not even a wireless mouse.

More information

[Masato (567927)]

I recently finished a research project on this subject and have actually had a chance to read a few of Kuhn's paper. From what I've seen and what other researchers have done, not a lot of thought has gone into making most equipment EMSEC compatible, so I'm not at all surprised by this finding. Most of the time, having "secure" equipment isn't required as very few individuals beyond large government entities have the money, resources and knowledge to be able to conduct such an attack. Extensive design and testing is required to ensure that equipment conforms to EMSEC standards and most companies are simply not willing to spend the extra money to certify their equipment for something very few people know anything about. According to Kuhn (see Security Limits for Compromising Emanations [cam.ac.uk] - warning PDF) emissions levels need to be as much as six orders of magnitude lower to prevent unauthorized snooping on most modern equipment.

Another paper that is very relevant to this article is from a Japanese group who did research on the same topic (LCDs, laptops, etc) A Trial of the Interception of Display Image using Emanation of Electromagnetic Wave [www.nict.jp] - again, a PDF. What's interesting to note from this paper is the fact that the researchers found that minor inconsistencies in the production of the equipment caused slightly different synchronous frequencies to be detected. This means in an office it could be possible for an attacker to "choose" which monitor they wish to look at by its frequency signature.

Re:

[n1hilist (997601)]

That's just going to make your signal even stronger!