this post was submitted on 26 Jul 2023
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Technology

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[–] [email protected] 4 points 1 year ago (4 children)

Just FYI, when your drive is encrypted, and the system is up and running, the keys for the encryption are in memory and thus recoverable. And even if they were magically protected by something like SGX or a some secure enclave, you can still interact with the machine and the filesystem while it is running.

So full disk encryption is NOT a silver bullet to data protection when being raided.

[–] [email protected] 3 points 1 year ago (1 children)

Right, and then these comments about “encrypted database” the server application needs to be able to access that data, so it will have the key in its config somewhere right?

[–] [email protected] 2 points 1 year ago

Yep. And homomorphic encryption is still very far away from being usable. Efficiency aside, the technology is patent encumbered, which is slowing down research into making it usable.

[–] [email protected] 2 points 1 year ago

Additionally, hardware-based solutions for attackers have been known for about fifteen years now. Wiebetech, for example, sells a nifty gadget that you plug into a UPS and then carefully slide over the power connector of a running machine. Then you pull the plug from the wall and the machine stays powered up. Net result: Contents of RAM are intact, encrypted drives are still accessible because the OS is still up.

[–] [email protected] 2 points 1 year ago (1 children)

Yeah I didn't realise they'd capture the memory. I though they just unplug the server and take it.

You could potentially have something that recognizes that the server is being tampered with and automatically shuts it down.

[–] [email protected] 1 points 1 year ago

Folks have been working on that for a while. I don't know if there are any usable tricks for that, though, been away from the game too long.

[–] [email protected] 1 points 1 year ago* (last edited 1 year ago) (2 children)

AFAIK it's not that easy to access data on the machine while it's running unless they can bypass the lock screen. People pick stupid passwords for their user accounts so it's totally possible to get in in those cases, but otherwise dont you need really sophisticated side channel attacks to get data out of memory on locked system? It's not like there is some port on the MOBO you can just plug into to get access to RAM

[–] [email protected] 1 points 1 year ago

I did some work on this a decade or so ago in college. Data stays in memory a lot longer than you'd think at room temp, like minutes, not seconds. If you spray the modules down with an upside down compressed air can, you have plenty of time to remove it, and plug it into some that can dump it to persistent storage.

[–] [email protected] 1 points 1 year ago

It's also possible to keep the lockscreen from coming up. The mouse cursor jigglers that folks buy as pranks these days started off as another device LEOs use during raids. I think Wiebetech invented that one, too.

As for dumping the contents of RAM from a running machine, look up "memory forensics." It's a thing that LEOs have done for quite a few years as well.