Hi, I’m running a ubuntu based backup server. And was wondering if there’s a simple way to encrypt my drives in case they get swiped or something by a break in. But also in a way that the computer can be restarted and decrypt the drive without me needing to stick a key in everytime. Any ideas? It seems basic but I’m not an expert on all these newfangled encryption terminology, so would like something idiot proof (by idiot proof, not idiot enough to lose/forget the decryption key)
LUKS can use a TPM now.
Wait, how’s this gonna help? If someone swipes the machine, they also have the TPM. TPM only helps against someone reading the disks on another machine. TPM is only useful to protect data during physical access if the rest of the firmware/software stack is impenetrable. In practical terms this would mean locked UEFI, disabled alternate boot device, Secure Boot, locked GRUB, and locked logins. In effect the security of the data is transferred from the knowledge of a passphrase to the knowledge of a login password, and the attack surface is expanded across multiple systems that all have to be secure and configured correctly to not allow access prior to OS login.
I read it as external drives, as someone “swiping the drives” without having stolen the whole ass computer kinda requires that?
I agree that if someone steals the whole computer, you’re pretty fucked unless you have a password entered somewhere in the chain to actually do the decryption, but I mean, they explicitly didn’t want that.
I’m not sure there’s a good way to encrypt a system that’ll boot with no interaction (and thus has to be able to decrypt itself with no input) and prevent access if it’s stolen.
This is one of those ‘software security doesn’t matter if you can’t guarantee physical security’ meta-problems, probably.
Yeah, you’re right, if it’s meant as disks-only, then TPM is the easy solution.
I think SSH unlocked LUKS at boot might be a decent compromise, with the SSH server at a different physical location.
I mean, TPM-locked machine with all the other parts configured correctly should be reasonably secure. It would boot without interaction and be available on the network. It would require a sophisticated and motivated actor to find a vulnerability in one of the systems in the boot chain to get in. That’s probably good enough for preventing data leaks from theft. But the user has to make sure the whole boot chain is configured securely.
Yeah, and the threat actor here is probably less ‘guy who knows Linux, LUKS, and how to bypass this’ and more ‘dude who wants to sell this for $5 on craigslist for more meth’, which pretty much means if the data is encrypted at rest and generally not accessible without logging in with a password they don’t have then it’s… probably fine?