6 ms·

Hard Drive of Hearing: Disks That Eavesdrop with a Synthesized Microphone [pdf]

96 points by gwern 7y ago

TimTheTinker 7y ago
Pasting relevant abstract section: > Our research demonstrates that the mechanical components in magnetic hard disk drives behave as microphones with sufficient precision to extract and parse human speech. These unintentional microphones sense speech with high enough fidelity for the Shazam service to recognize a song recorded through the hard drive. This proof of concept attack sheds light on the possibility of invasion of privacy even in absence of traditional sensors. We also present defense mechanisms, such as the use of ultrasonic aliasing, that can mitigate acoustic eavesdropping by synthesized microphones in hard disk drives. So this attack is for magnetic HDDs, not SSDs or flash media.
- imhoguy 7y ago
  Waiting for a day to be able to mod SSD into SDR /s
  - afandian 7y ago
    I bet there's already a MEMS accelerometer in there somewhere.
- User23 7y ago
  This reminds me of the TEMPEST attack on CRTs. I'd bet dollars to donuts some fine folks at the NSA have known about this for years.
lonyi 7y ago
Summarization from The Register: https://www.theregister.co.uk/2019/03/07/hard_drive_eavesdropping/ https://www.theregister.co.uk/2019/03/07/hard_drive_eavesdro...
trdtaylor1 7y ago
For those now questioning hard drives in their security arenas. The 'researchers' (again, it's Wenyuan Xu, she's the clickbait of security research) took computer speakers on nearly max volume onto either side of a hard drive. Shazam barely recognizes the song (more often recognizes it as something else). Wenyuan does this every time.
- geofft 7y ago
  Isn't that what security researchers are supposed to do? Find the most implausible-sounding attacks, get them to work at least some of the time? I would not be reassured by someone telling me "well, most of the time, there's too much noise to get a reliable side channel out of Spectre."
  - pour778yy 7y ago
    What does it matter when Facebook, Equifax and the like are let off the hook anyway? We know they’re selling the data anyway? So it’s not privacy we’re protecting but corporate bottom lines (if everyone has it the data has less value). There is no truly secure computer system because there is no security from laws of nature and human avarice. There’s always a relative position from which one can get the data they need. The best security we have is competent, functioning government diffusing and negotiating stable arrangements. IMO we’ve pushed too many paranoias from social norms into products we build. Your data isn’t secure and there is no changing that. And really the data isn’t THAT valuable. We’re just excited by a new level of granularity. This is promises of “nuclear powered rocket cars” all over again. Sure there’s some novelty coming from it in scientific realms, but it’s largely useless to day to day life (only a truly lazy person can’t be bothered to phone call in their hair appointments). Steve Bannon got all !! over data showing people that live by a church.... go to the church. Pretty sure that was already well known. That’s the sort of “value” we’re achieving with all this big data. Obvious answers we’re already familiar with. Cause there are few interesting questions left to be asked about us in a context of “who are we in daily life.”
  - madez 7y ago
    Indeed. And a today barely usable weakness can be tomorrows glaringly exploitable security hole. If we are aware of the problems, we can at least make sure to not make them bigger.
anfractuosity 7y ago
There's also the interesting talk on it here - https://www.youtube.com/watch?v=EvoOP6iKYMQ https://www.youtube.com/watch?v=EvoOP6iKYMQ
OnACoffeeBreak 7y ago
Their setup it's arguably contrived. HHD is in an external enclosure with a fan. While they turn the fan too max power in an attempt to get a more typical or "worst case" setup, it seems to me that is far from a common setup of a hard drive inside a computer chassis with associated mounting hardware between the HHD and source of speech.
trhway 7y ago
i think the other direction it would work too - generating HDD head movements in a way to encode info in the resulting noise - taken together with the OP it means that one can cross the air gap in both directions (the Cuban sounds look more and more like an electronic attack with humans being just an unfortunate collateral). Similar things can probably be done with the CPU/case fans - thus for example a "bad" motherboard can talk and listen to the world.
- userbinator 7y ago
  generating HDD head movements in a way to encode info in the resulting noise That's not so interesting, as anyone who has used a machine with an audible hard drive knows --- you can tell whether the system is idle, working, or doing something strange ("I'm not doing anything that would write to the disk, why is it still grinding?") just by the sound.
  - trhway 7y ago
    you can encode it into a normally working mode - say by slightly varying timings of head movements during legit disk ops, kind of frequency coding.
    - anticensor 7y ago
      That would be an interesting advancement.
kartan 7y ago
This reminds me of a similar article many years ago about reading network packet content from the light of the led in network cards. It is another example of how things are safer in practice than in theory. Entropy helps to keep things safe by introducing noise. All these measures are easier in a lab than in the wild.
- anfractuosity 7y ago
  I guess you might mean this paper which is very cool - http://applied-math.org/optical_tempest.pdf http://applied-math.org/optical_tempest.pdf
pmorici 7y ago
I'm kind of surprised to learn this wasn't obvious or already known. People have been hacking old hard drives into crappy speakers for a long time there are countless examples of this on Youtube. Perhaps the most artistic is a rendition of Radio Head's, Big Ideas (Don't Get Any) played on a Sinclair ZX Spectrum attached to an array of hard drives. [0] I always just assumed that any thing that acts like a speaker could also be made to act like a Mic. [0] https://vimeo.com/1109226 https://vimeo.com/1109226
ctdonath 7y ago
A stretch, yes. But gone from "ludicrous & delusional" to "proof of concept". Now apply government intelligence service funding, plus no limiting accountability, plus motivation/target.
mikece 7y ago
Only slightly tangential but every time I see another story about a new way to conduct surveillance I can't help wondering if Rockwell had seen the future and was trying to warn us with his song "I feel like someone is watching me." https://youtu.be/7YvAYIJSSZY https://youtu.be/7YvAYIJSSZY
Severian 7y ago
Classic clip from 2008 https://www.youtube.com/watch?v=tDacjrSCeq4 https://www.youtube.com/watch?v=tDacjrSCeq4

96 points by gwern 7y ago

Pasting relevant abstract section: > Our research demonstrates that the mechanical components in magnetic hard disk drives behave as microphones with sufficient precision to extract and parse human speech. These unintentional microphones sense speech with high enough fidelity for the Shazam service to recognize a song recorded through the hard drive. This proof of concept attack sheds light on the possibility of invasion of privacy even in absence of traditional sensors. We also present defense mechanisms, such as the use of ultrasonic aliasing, that can mitigate acoustic eavesdropping by synthesized microphones in hard disk drives. So this attack is for magnetic HDDs, not SSDs or flash media.

imhoguy 7y ago
Waiting for a day to be able to mod SSD into SDR /s
- afandian 7y ago
  I bet there's already a MEMS accelerometer in there somewhere.
User23 7y ago
This reminds me of the TEMPEST attack on CRTs. I'd bet dollars to donuts some fine folks at the NSA have known about this for years.

lonyi 7y ago

Summarization from The Register: https://www.theregister.co.uk/2019/03/07/hard_drive_eavesdropping/ https://www.theregister.co.uk/2019/03/07/hard_drive_eavesdro...

trdtaylor1 7y ago

For those now questioning hard drives in their security arenas. The 'researchers' (again, it's Wenyuan Xu, she's the clickbait of security research) took computer speakers on nearly max volume onto either side of a hard drive. Shazam barely recognizes the song (more often recognizes it as something else). Wenyuan does this every time.

geofft 7y ago
Isn't that what security researchers are supposed to do? Find the most implausible-sounding attacks, get them to work at least some of the time? I would not be reassured by someone telling me "well, most of the time, there's too much noise to get a reliable side channel out of Spectre."
- pour778yy 7y ago
  What does it matter when Facebook, Equifax and the like are let off the hook anyway? We know they’re selling the data anyway? So it’s not privacy we’re protecting but corporate bottom lines (if everyone has it the data has less value). There is no truly secure computer system because there is no security from laws of nature and human avarice. There’s always a relative position from which one can get the data they need. The best security we have is competent, functioning government diffusing and negotiating stable arrangements. IMO we’ve pushed too many paranoias from social norms into products we build. Your data isn’t secure and there is no changing that. And really the data isn’t THAT valuable. We’re just excited by a new level of granularity. This is promises of “nuclear powered rocket cars” all over again. Sure there’s some novelty coming from it in scientific realms, but it’s largely useless to day to day life (only a truly lazy person can’t be bothered to phone call in their hair appointments). Steve Bannon got all !! over data showing people that live by a church.... go to the church. Pretty sure that was already well known. That’s the sort of “value” we’re achieving with all this big data. Obvious answers we’re already familiar with. Cause there are few interesting questions left to be asked about us in a context of “who are we in daily life.”
- madez 7y ago
  Indeed. And a today barely usable weakness can be tomorrows glaringly exploitable security hole. If we are aware of the problems, we can at least make sure to not make them bigger.

anfractuosity 7y ago

There's also the interesting talk on it here - https://www.youtube.com/watch?v=EvoOP6iKYMQ https://www.youtube.com/watch?v=EvoOP6iKYMQ

OnACoffeeBreak 7y ago

Their setup it's arguably contrived. HHD is in an external enclosure with a fan. While they turn the fan too max power in an attempt to get a more typical or "worst case" setup, it seems to me that is far from a common setup of a hard drive inside a computer chassis with associated mounting hardware between the HHD and source of speech.

trhway 7y ago

i think the other direction it would work too - generating HDD head movements in a way to encode info in the resulting noise - taken together with the OP it means that one can cross the air gap in both directions (the Cuban sounds look more and more like an electronic attack with humans being just an unfortunate collateral). Similar things can probably be done with the CPU/case fans - thus for example a "bad" motherboard can talk and listen to the world.

userbinator 7y ago
generating HDD head movements in a way to encode info in the resulting noise That's not so interesting, as anyone who has used a machine with an audible hard drive knows --- you can tell whether the system is idle, working, or doing something strange ("I'm not doing anything that would write to the disk, why is it still grinding?") just by the sound.
- trhway 7y ago
  you can encode it into a normally working mode - say by slightly varying timings of head movements during legit disk ops, kind of frequency coding.
  - anticensor 7y ago
    That would be an interesting advancement.

kartan 7y ago

This reminds me of a similar article many years ago about reading network packet content from the light of the led in network cards. It is another example of how things are safer in practice than in theory. Entropy helps to keep things safe by introducing noise. All these measures are easier in a lab than in the wild.

anfractuosity 7y ago
I guess you might mean this paper which is very cool - http://applied-math.org/optical_tempest.pdf http://applied-math.org/optical_tempest.pdf

pmorici 7y ago

I'm kind of surprised to learn this wasn't obvious or already known. People have been hacking old hard drives into crappy speakers for a long time there are countless examples of this on Youtube. Perhaps the most artistic is a rendition of Radio Head's, Big Ideas (Don't Get Any) played on a Sinclair ZX Spectrum attached to an array of hard drives. [0] I always just assumed that any thing that acts like a speaker could also be made to act like a Mic. [0] https://vimeo.com/1109226 https://vimeo.com/1109226

ctdonath 7y ago

A stretch, yes. But gone from "ludicrous & delusional" to "proof of concept". Now apply government intelligence service funding, plus no limiting accountability, plus motivation/target.

mikece 7y ago

Only slightly tangential but every time I see another story about a new way to conduct surveillance I can't help wondering if Rockwell had seen the future and was trying to warn us with his song "I feel like someone is watching me." https://youtu.be/7YvAYIJSSZY https://youtu.be/7YvAYIJSSZY

Severian 7y ago

Classic clip from 2008 https://www.youtube.com/watch?v=tDacjrSCeq4 https://www.youtube.com/watch?v=tDacjrSCeq4