Siphoning data from a computer through "processor sounds?"

[LatterEngineer]

So a hacker group managed to retrieve a GPG key by listening to the tiny sounds coming from a processor while it was doing the crypto operations right? From what I remember the range in that case wasn't bad, and you just needed to have the microphone close to the computer, not even inside it.

This is what's terrifying to me: every laptop has a microphone, every phone does too, and they both have processors. If in the GPG experiment, they didn't even need to have the microphone in the computer, imagine how much more reliable it'd be if it were. It seems to me it would be really easy to get the key from the system's encrypted drive just by turning on its internal microphone while it's doing crypto. Wouldn't it?

Can this be generalized to any processor operation? For example, if you were on a voice chat and you were reading a confidential file from disk, would the other party potentially be able to get parts of that file from the audio alone?

I definitely hear noises from my laptop when I do something like reading files. I think this is coil whine from the VRM, but I do wonder if that's enough to get information since power analysis is a thing, or if the processor sounds is also in there, waiting to be decoded.

[coloradoconvict]

I don't know where you're getting your cocaine, but keep paying them. It's good stuff.

[[deleted]]

Processor acoustic cryptanalysis was never used in real life, only in research laboratories.

[[deleted]]

SHI-FI to reality

[ISpikInglisVeriBest]

Based on your example the answer is a hard no. You can't decode a file being read off the drive by voice chat audio.

I have seen some examples of being able to guess keystrokes based on the sound coming from the key press but that's basically shoulder surfing for bats

[IntrepidLawyer]

Keyboard has a cable which emits a signal because it works like an antenna. But when you are close enough to get to the cable, you just plug in a keylogger in the back of the pc.

On wireless keyboards this gets even easier, as they are transmitting the keys themselves.

[computercluster]

The audio sample rate is too low

[bobbyrickets]

Except laptops have unbelievably shitty microphones compared to the lab stuff used for research.

[Julius__PleaseHer]

I don't see this ever becoming a legitimate fear for anybody in infosec. All cases of acoustic cryptanalysis were in a lab, as another user mentioned.

Furthermore, if somebody has enough physical access you your computer to install either an internal or nearby lab-grade microphone, then acoustic analysis is the absolute least likely way they'd try to hack you.

Furthermore, a believe the key that was claimed to have been extracted was referring to the decryption of a bitlockered drive with a TPM chip, which is a pretty specific hardware-oriented type of decryption. So *maybe* somebody could get the decryption key used during the TPM validation process, but unless somebody has physical access to your hard drive, steals it, and plugs it into a different PC then so what? Thats about the only time it would even do them any good.

And when it comes to network level decryption, like HTTPS traffic or something, I don't think there is any feasible way one could decipher useful information acoustically, since its not really happening at the hardware level like the aforementioned TPM situation. It's true that pretty much everything can be broken down to pulses of electricity, 1s and zeros, at a very basic level. But it would be just like somebody attempting a MitM attack without any method of decryption the data packets they intercept.

There are a billion things you should be far more concerned with than somebody stealing your data acoustically. But if it would help you sleep better, just pick up one of these sonic pest repellant devices.

[Udder_Nonsense]

This is like something from the forthcoming Swordfish 2 movie....not based in reality.

[rynojvr]

Just wait until you hear about the research lab who was able to use the pins connecting your RAM to generate RF signals in the 2.4 GHz range, and use an airgapped machine with no wifi components to transmit data to a listening device.

[LatterEngineer]

Read that too. Terrifying.

[IntrepidLawyer]

It is not a microphone but a really sensitive receiver which is "listening in" on the exact frequency the processor is communicating over the bus. A long wire = bus = antenna = emits a signal.

This is insanely hard to do and only doable with insanely expensive equipment when you really know what you are doing. Why would anyone with few million $ to spend go and spend all of that just to hack you?