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
Honestly, I am just so curious about your threat model that you are considering this for self hosting.
What do you mean?
Sharing this article as I think it ties in with this conversation well: https://www.zdnet.com/article/cryogenically-frozen-ram-bypasses-all-disk-encryption-methods/
I do want to say that for most people, this is likely NOT a concern, but I don’t know OPs threat model.
OP is likely Raoul Silva, the antagonist from Skyfall (2012).
For those not clicking the link, “cryogenically frozen” actually means an upside down can of compressed air.
That was a perfect one sentence summary of the article!
Its amazing some of the things people come up with like gathering intel on what a computer is doing via power draw changes, monitoring an air-gapped computers electromagnetic fields, or in this case “cryogenically” freezing ram with compressed air.
The key needs to be available to continue to be able to decrypt the data on the device. All encrypted data is not decrypted as you mount or unlock your encrypted device, that is done one the fly as you use it.
The attack you are thinking of should also not be relevant. What you worry about appears to imply that you are more concerned about the key being protected, rather than the data the key protects. You seem to wish to have your decrypted data available, but not the key.
Thank you, I realise that what I’m asking for might not be physically possible. I’m certain that RAM loses all of its contents after a loss of power, but would it be possible to pad the RAM before/during the shutdown process to make sure that nobody gets to the key?