(Link to a program that does this.)

  • @ericbuijs@lemmy.ml
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    3 years ago

    Perhaps a little bit of topic but this post takes me back 40 years. In the '80s computer code was distributed over a radio signal. First on FM later on AM. On the receiving end me and many other computer enthusiasts were recording this signal on a little cassette recorder. The recorder was then connected to the computer and we could load the source. O, sweet nostalgia. Copyright on software didn’t exists and we had never heard of Bill Gates. I suddenly feel very old now ;-)

    • @LemonWedge@lemmy.ml
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      23 years ago

      Takes me back to the Spectrum days! Copying cassettes using my parents twin deck separates system with the volume dial down to 0.

  • poVoq
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    153 years ago

    This is basically how internet modems over telephone lines used to work.

  • @onlooker@lemmy.ml
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    93 years ago

    Apparently, there are SO many ways to do this. If anyone is interested in this sort of thing, check out the papers made by Ben-Gurion University’s Cyber-Security Research Center. They discovered all kinds of methods which can be used to steal data, which are, but are not limited to:

    • using Keyboard LEDs
    • heat emanations
    • screen brightness

    Seriously, it’s as insane as it is fascinating. They even know how to extract data through a Faraday cage. Their latest discovery seems to be this article and their previous ones can be found towards the bottom of the same page.

    • ᗪᗩᗰᑎ
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      23 years ago

      By listening to the sound of your typing - https://github.com/ggerganov/kbd-audio - although it works best/only with mechanical keyboards in a noise-free environment.

      That said, and not to discount the possibility, but most of these techniques are generally impractical and tend to require mostly perfect conditions - like the source code linked above working with mechanical keyboards.

  • Dessalines
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    63 years ago

    10 kB / s isn’t bad. I wonder if there’s some other innovative way to do this, like with cameras instead of microphones, so pictures, or video.

    • m-p{3}
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      33 years ago

      I wonder how fast data could be transferred over a series of QR Codes being scanned sequentially.

      You also have the benefit of choosing how resilient the data transfer should be to loss by adjusting the error correction level at the detriment of how much data per QR code you can transmit.

    • @AgreeableLandscape@lemmy.ml
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      3 years ago

      I once saw a project being shared on Reddit that encodes arbitrary data as a video of coloured blocks. It’s apparently even pretty robust to compression/transcoding, as the OP uploaded a generated video to YouTube and still managed to decode it after it’s been processed. I seem to have lost the link to it though :(

  • @pinknoise@lemmy.ml
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    3 years ago

    If you’r ok with the lower bandwith you can also use >17kHz which old folks can’t really hear :D

  • @AgreeableLandscape@lemmy.ml
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    3 years ago

    A research group once, I shit you not, put varying CPU loads on a target airgapped computer and “transmitted” data encoded as fan noises going high and low. There have also been cases of getting GPG keys in lab settings by literally listening to the tiniest of noises made by the processor as it works! (I believe it’s coil whine? But I can’t seem to find the article explaining it) Information leakage is an absolute nightmare to try and completely prevent if your attacker is determined/skilled enough.

    • @Echedenyan@lemmy.ml
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      3 years ago

      The thing you tell about processor is right.

      There is a thing called cache timing and a vulnerability was discovered for the same with but the voltage used.