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Stealing Keys From a Laptop In Another Room — and Offline
Motherboard carries a report that with equipment valued at about $3,000, a group of Israeli researchers have been able to extract cryptographic keys from a laptop that is not only separated by a physical wall, but protected by an air gap. This, they say, "is the first time such an approach has been used specifically against elliptic curve cryptography running on a PC." From the article:
The method is a so-called side-channel attack: an attack that doesn't tackle an encryption implementation head on, such as through brute force or by exploiting a weakness in the underlying algorithm, but through some other means. In this case, the attack relies on the electromagnetic outputs of the laptop that are emitted during the decryption process, which can then be used to work out the target's key.
Specifically, the researchers obtained the private key from a laptop running GnuPG, a popular implementation of OpenPGP. (The developers of GnuPG have since released countermeasures to the method. Tromer said that the changes make GnuPG âoemore resistant to side-channel attack since the sequence of high-level arithmetic operations does not depend on the secret key.â)
Heh, time for TEMPEST. But isn't this what the spread-spectrum bus modes are supposed to help reduce?
Part of the plot in the 1999 novel Cryptonomicon by Neal Stephenson so this isnt new.
Are there any computer or laptop cases which can help to shield or contain information leakage like this from getting out?
This is why our government uses the "Tempest" certification on buildings, categorizing whether information can be stolen from electromagnetic emanations within neighboring wall, room, just outside the building, etc.
It's called Van Eck phreaking, and it's one of the many modern day forms of wizardry. Essentially different components of your computer communicate via high frequency electric currents. These currents broadcast corresponding EM waves somewhere in the radio spectrum, and you decode the corresponding frequency components into your own information, which if you know what monitor they're using, for instance, you can catch the signal from their wires and reproduce their monitor image on your screen.
When performing different operations, computers emit different EM signals. EM antennae and post-processing software have become sufficiently fast and accurate that if you know the source code of an encryption algorithm, you can trace through the code non-intrusively, simply by watching for patterns in the emitted EM radiation. As it happens, GnuPG's EEC implementation performed different operations depending on the private key, so you can reconstruct the private key. GnuPG's developers addressed this by changing the implementation to try to ensure that the same sequence of operations will always get executed, regardless of the key. This is similar to how cryptographic string comparisons always compare all characters in a string and don't stop when they encounter the first difference, as normal string comparisons do.
poor quality motherboard
http://9su.ru
Offline as in not connected not offline as in off.
Minimum threshold fixed. Thanks!
This Day on Slashdot -- "2010 PA School Spied On Students Via School-Issued Laptop Webcams "
Here's a little follow-up:
In this case, a school had spying software put on their laptops that they loaned to their students. Turns out school officials were using the software to "check up" on their kids, sometimes in compromising situations. The activity was discovered and the school sued. Settlement was in the neighborhood of $600,000.
The IT Director who allowed this to happen: Virginia DiMedio. This "lady" shut down an IT student intern who raised objections about the spying software, telling him to “take a breath and relax,”... "we are not a police state" when in fact they were a police state. When the shit hit the fan, Virginia got the axe as she should. She couldn't get another IT job and now teaches Pilates.
https://www.linkedin.com/in/virginia-dimedio-4a87a430
Power corrupts. Never forget it.
I currently have 300 processes running on my laptop, more on my server. I really wonder how they can filter out the noise of 299 of them to find out the electromagnetic noise of the PGP process (which lasts for only a split second) and THEN exploit that. It's one thing to get the Van Eck of an analog signal of a monitor (two very regular frequencies), another one entirely to get this of an 8 core CPU which uses variable frequencies depending on load.
Non-Linux Penguins ?
Are there any computer or laptop cases which can help to shield or contain information leakage like this from getting out?
Tinfoil would seem an obvious solution. :-)
That's kind of amazing. We've all heard about it being theoretically true, and assumed it was totally implausible.
Scary, and a little too sci-fi turned real.
Lost at C:>. Found at C.
I understand that storing your mail server in the bathroom prevents this attack?
Because even if you have 300 processes running, the 299 could be ignored because of their "cpu fingerprint".
They do not occupy one CPU to the max, most processes running on a computer do just a bit more than nothing.
I have the uncanny feeling that GnuPG is not parallalized at all.
A crypto application however runs - if it's not parallelized - on one CPU-Core 100% for a depending on the processing power of the machine certain amount of time.
(In crypto does not like timing sidechannel attacks)
I guess, without having read the article, this specific burst of activity is where a crypto "broadcast" can be identified by.
When I would attack a webservers private key using this tactic, I would just initiate a https connection and send certain data and than would see the what the spectrum says, I would then repeat it .. and I recognize patterns, and a again and again and again, till I have gathered enough data.
However I think your point hints at a possible counter measure, having similar fingerprints also similarly timed it would interfere with the "broadcast".
Tromer said that the changes make GnuPG Ãoemore resistant to side-channel attack since the sequence of high-level arithmetic operations does not depend on the secret key.Ã
Hey, speaking of character encoding on Slashdot...
- or -
Hey, use the "Preview" button!
Bonus funny: that changed from a lowercase 'a' with a '^' to an uppercase 'A' with a '~' while posting.
Dear Slashdot: next time you want to mess with the site, add a rich-text editor for comments.
While you can still do some side surfing on them, the minute power of the battery makes using Van Eck phreaking much harder. Of course, you still have the problem of the monitor, but at least you have kept the keys secret.
excitingthingstodo.blogspot.com
not only separated by a physical wall, but protected by an air gap
Normally you put the most surprising thing second. In this context a physical wall is an "air gap."
systemd is Roko's Basilisk.
aaaaaa......aaaaaaabbbb......bbbbb.....?
The sheer number of processes and em waves emitted from a standard computer setup is not going to help in isolating the em output. Strangely enough you surfing around is more resistant to this than a machine used primarily to encrypt/decrypt. Makes an interesting case against single use compute time.