this post was submitted on 29 Feb 2024
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From the info I've gathered, it seems that LUKS over LVM is the "proper" way as ideally you'd only want to encrypt swap, /tmp and /var. (/tmp and /var are places for temporary files, ie. opening a .zip archive. Swap is just RAM on your hard drive, so a place where your passwords could be stored) Encrypting the root (equivalent of "program files" in Windows) won't make your system more secure, just slower. (If you live in a place where you need to keep the list of your installed apps private, you'd probably be fricced by using encryption anyways.) Home directory should obviously be encrypted ~~but for the best performance you should use file level encryption instead of block level. ~~ edit: Do your own research on the performance, a reply claims otherwise, though leaving root partition unencrypted obviously increases R/W speed.
The thing is that setting it up this way is pretty hard so distros generally use 2 easier methods to setup encryption. Either encrypt the whole disk (LVM over LUKS) or encrypt only the home directory. I wonder whether the latter is secure enough though. Mint for example does not explicitly state that swap, /var and /tmp are encrypted when you select "encrypt home directory" but on Cinnamon there is not hibernation option so there is a chance that Swap is encrypted, just with a one-time password, which gets generated on boot and deleted after shutdown. <--- citation needed...edit: I've just tried hibernating in Mint without FDE and it didn't work, you just get a new session after resuming, so that's good.
Relevant article: https://www.linuxinsider.com/story/the-case-against-full-disk-encryption-86774.html
also: https://wiki.archlinux.org/title/Data-at-rest_encryption#Block_device_vs_stacked_filesystem_encryption
I though FDE is to thwart physical access to exfiltrate and or recover data. Making the root partition unencrypted surely will boost performance but I feel like this opens up an additional avenue for an attacker to exploit and defeat the purpose of doing FDE? It isn't just making "installed apps private" but literally replace some binaries with a backdoored version of it with then enables access to decrypted data.
If an attacker has physical access to your device, you should not use the device afterwards, ever. There are some mitigations like Secure Boot and Heads OS, but they only slow down the attacker. Given enough time, you cannot stop him. Heads OS is pretty much for giving your laptop to airport security temporary and Secure Boot has been hacked in a minute. Although that was using TMP outside of the CPU, I would not trust Secure Boot with TMP 2.0 for anything other than a quick customs check either.
Using FDE as a protection against physical attacks is just a false sense of security. Veracrypt for example go as far as to say that secure boot is false sense of security.
For maximum paranoia there is a use for FDE, though. If you install a crappy app that saves data outside of RAM, /home, /var and /tmp, the data won't get leaked. Though that would be a massive security issue because most linux computers are servers which cannot use FDE.
The most common physical attacks will be you misplacing your device or some friend/burglar/cop taking it. FDE works great in those scenarios.
Not really, rewriting the boot sector with your malware can be scripted so even the average burglar could use it. Using a previously stolen laptop without reflashing the firmware or something similar isn't worth the risk imo.