This is a very weak dismissal. Have you read the actual details they claim?
Side-channel attacks (like power analysis) in the presence of other activity are well established.
Electrical signals causing audible frequency output are also well established. Look up the piezoelectric effect[1], or magneto/electrostiction[2][3]. The demand for miniaturisation of everything means even at low voltages, there are quite substantial electric fields across small distances, which are enough to flex the material audibly.
On the magnetostriction side, the flyback transformer in old CRT televisions is a perfect example. Myself and many people have been able to tell whether the TV was powered up (even if totally muted) from outside the room (and yes, double-blind tested repeatedly).
What does wire gauge have to do with anything?
On the practicality/data rate issue, a nice quote from the very intro of their paper states:
In a nutshell, the key extraction attack relies on crafting chosen ciphertexts that cause numerical
cancellations deep inside GnuPG’s modular exponentiation algorithm. This causes the special value
zero to appear frequently in the innermost loop of the algorithm, where it affects control flow. A single
iteration of that loop is much too fast for direct acoustic observation, but the effect is repeated and
amplified over many thousands of iterations, resulting in a gross leakage effect that is discernible in the
acoustic spectrum over hundreds of milliseconds.
(emphasis mine)
It seems that the main focus of their work is to fingerprint the crypto and identify that a particular key was used (but not necessarily what the key is), which is a much easier problem than the one they talk about here, which requires specially crafted input over a substantial period of time.
Your solution might work, or it might just lower the SnR of the signal and require filtering larger quantities of data to extract the desired signal again.
The road to crypto-hell is paved with people who thought that they could use their "common sense" to reason intuitively about their problem. But to paraphrase Feynman, Mother Nature is not swayed by persuasive arguments.
I am one of those people who can hear a CRT television from a room or two over. Comes across as a very distinctive high pitched squeal. I always assumed that other people couldn't hear it simply because it was too high.
It actually seemed worse when my LCD TV broke last year and I pulled out my old CRT to watch a movie in the meantime. I don't know if I had just grown unaccustomed to hearing it or what, but it was annoying me even through the sounds of the movie.
Whoa, I had to reread your comment twice to understand it properly. In the context of RSA, and particularly speaking about its weaknesses, for me "CRT" automatically stands for "Chinese Remainder Theorem"… :-D.
If that interest someone, look for the BellCoRe attack on CRT-RSA [1,2]. I'm also working on the countermeasure as part of my PhD [3,4], and it's quite some fun!
Thanks for your constructive reply. Your exact statement was:
Can data be transferred via acoustics over a 2 conductor 16 gauge wire at the speeds memory is accessed or is sent to the CPU? No
Which is of course true, if you're talking about >GB/s signals over wide buses.
But we're not. So I don't see why it's relevant here.
These attacks are not "sniff the actual data the CPU is flinging around by coupling to signal traces", so they don't need anything like full data-rate capability.
Edit: On re-reading your claim again, I noticed the phrase "transferred via acoustics over a 2 conductor 16 gauge wire" is a bit ambiguous.
Do you mean transferred electrically over those wires, but limited to the typical acoustic frequency band (say, 0-20kHz)? Or do you mean actually acoustically coupled as mechanical vibrations of the wire itself? I can't imagine it makes any difference to my argument above, but I do wonder.
Comments
This is a very weak dismissal. Have you read the actual details they claim?
Side-channel attacks (like power analysis) in the presence of other activity are well established.
Electrical signals causing audible frequency output are also well established. Look up the piezoelectric effect[1], or magneto/electrostiction[2][3]. The demand for miniaturisation of everything means even at low voltages, there are quite substantial electric fields across small distances, which are enough to flex the material audibly.
On the magnetostriction side, the flyback transformer in old CRT televisions is a perfect example. Myself and many people have been able to tell whether the TV was powered up (even if totally muted) from outside the room (and yes, double-blind tested repeatedly).
What does wire gauge have to do with anything?
On the practicality/data rate issue, a nice quote from the very intro of their paper states:
(emphasis mine)
It seems that the main focus of their work is to fingerprint the crypto and identify that a particular key was used (but not necessarily what the key is), which is a much easier problem than the one they talk about here, which requires specially crafted input over a substantial period of time.
Your solution might work, or it might just lower the SnR of the signal and require filtering larger quantities of data to extract the desired signal again.
The road to crypto-hell is paved with people who thought that they could use their "common sense" to reason intuitively about their problem. But to paraphrase Feynman, Mother Nature is not swayed by persuasive arguments.
[1] https://en.wikipedia.org/wiki/Piezoelectricity
[2] https://en.wikipedia.org/wiki/Magnetostriction
[3] https://en.wikipedia.org/wiki/Electrostriction
I am one of those people who can hear a CRT television from a room or two over. Comes across as a very distinctive high pitched squeal. I always assumed that other people couldn't hear it simply because it was too high.
It actually seemed worse when my LCD TV broke last year and I pulled out my old CRT to watch a movie in the meantime. I don't know if I had just grown unaccustomed to hearing it or what, but it was annoying me even through the sounds of the movie.
Whoa, I had to reread your comment twice to understand it properly. In the context of RSA, and particularly speaking about its weaknesses, for me "CRT" automatically stands for "Chinese Remainder Theorem"… :-D.
If that interest someone, look for the BellCoRe attack on CRT-RSA [1,2]. I'm also working on the countermeasure as part of my PhD [3,4], and it's quite some fun!
[1] http://cryptome.org/jya/smart.pdf
[2] http://eprint.iacr.org/2012/553
[3] http://eprint.iacr.org/2013/506
[4] http://eprint.iacr.org/2013/810
If you have to ask any of the rest of your arguments are invalidated.
Thanks for your constructive reply. Your exact statement was:
Which is of course true, if you're talking about >GB/s signals over wide buses.
But we're not. So I don't see why it's relevant here.
These attacks are not "sniff the actual data the CPU is flinging around by coupling to signal traces", so they don't need anything like full data-rate capability.
Edit: On re-reading your claim again, I noticed the phrase "transferred via acoustics over a 2 conductor 16 gauge wire" is a bit ambiguous. Do you mean transferred electrically over those wires, but limited to the typical acoustic frequency band (say, 0-20kHz)? Or do you mean actually acoustically coupled as mechanical vibrations of the wire itself? I can't imagine it makes any difference to my argument above, but I do wonder.