Hi everyone, I found the great question on booting encrypted drives, and since I’m somewhat paranoid I’d like to ask a follow-up:

When the key to decrypt the drive is input into the system, I’m assuming it stays in the RAM till the time the computer shuts downs. We know that one could, in theory, get a dump of the contents of the RAM in such a state, if done correctly. How would you deal with this problem? Is there some way to insert the USB, decrypt the drive, and then remove the USB and all traces of the key from the system?

Thanks!

Edit: link to the question I referenced: https://feddit.de/post/6735667

  • MigratingtoLemmy@lemmy.worldOPEnglish
    2·
    11 months ago

    Thank you for the comprehensive answer. I will go through it again and attempt to implement some of these mitigations.

    Thanks again, I saved your comment

    • aard@kyu.deEnglish
      8·
      11 months ago

      Take into account that your average police raid will not attempt that - they just don’t have the means for that.

      If you have managed to become an important enough target that either specialists get called in, or you’ve managed to become target of three letter agencies or the equivalent in your country you will have been targeted by other attacks to gain access to your data, both software and hardware - and if you have to ask that kind of question here you’re very unlikely to successfully defend against them.

      • MigratingtoLemmy@lemmy.worldOPEnglish
        1·
        11 months ago

        Thanks for your reply. Fortunately, I am not a person under such scrutiny, and the only reason I ask this is because I’m paranoid.

        • aard@kyu.deEnglish
          4·
          11 months ago

          This level of paranoia isn’t really compatible with modern hardware, and requires a lot of effort.

          You’re pretty much limited to stuff that has open firmware available, and even then you have to hope there are no bugs or backdoors in the hardware.

          For the intel world almost everything with open firmware is pretty old - some nowadays unsupported, which means no longer microcode updates. And those microcode updates also are a problem - you can’t mitigate everything in kernel space, so usually you’d want them, but they’d also be an attack vector against you.

          And even if you manage to trust the computer itself there are a lot of attack vectors surrounding it. Do you have anything capable of recording audio in the same room as your computer? If yes, not a good idea - it has been proven possible to extract passwords from audio recordings of a keyboard. Does the room have windows? That counts as an audio recording device.

          If you got rid of that, do you have some other hardware with sensors? There’s a high chance that a device placed on your desk containing an accelerometer would also be capable of extracting your password.