Flash drive hidden under the carpet and connected via a USB extension, holding the decryption keys - threat model is a robber making off with the hard drives and gear, where the data just needs to be useless or inaccessible to others.
There’s a script in the initramfs which looks for the flash drive, and passes the decryption key on it to cryptsetup, which then kicks off the rest of the boot mounting the filesystems underneath the luks
I could technically remove the flash drive after boot as the system is on a UPS, but I like the ability to reboot remotely without too much hassle.
What I’d like to do in future would be to implement something more robust with a hardware device requiring 2FA. I’m not familiar with low level hardware security at all though, so the current setup will do fine for the time being!
I used to run a TFTP server on my router that held the decryption keys.
As soon as a machine got far enough in the boot sequence to get network access, it would pull the decryption keys from the router.
That way a thief would have to steal the router along with the computer, and have the router running when booting up the computer.
It works wirelessly, too!
Flash drive hidden under the carpet and connected via a USB extension, holding the decryption keys - threat model is a robber making off with the hard drives and gear, where the data just needs to be useless or inaccessible to others.
This is a pretty clever solution. Most thieves won’t follow a cable that for all intents looks like a network cable, especially if it disappears into a wall plate or something.
I don’t think most thieves care much about the data on the computer in the first place. Steal hardware, fresh install of Windows on it and straight to the pawn shop.
Agreed. Even just putting a non-Windows/Mac compatible file system on it may have the same effect. They cannot see files when they plug the drive into their PC or Mac, so they probably also just format it.
Flash drive hidden under the carpet and connected via a USB extension, holding the decryption keys - threat model is a robber making off with the hard drives and gear, where the data just needs to be useless or inaccessible to others.
There’s a script in the initramfs which looks for the flash drive, and passes the decryption key on it to cryptsetup, which then kicks off the rest of the boot mounting the filesystems underneath the luks
I could technically remove the flash drive after boot as the system is on a UPS, but I like the ability to reboot remotely without too much hassle.
What I’d like to do in future would be to implement something more robust with a hardware device requiring 2FA. I’m not familiar with low level hardware security at all though, so the current setup will do fine for the time being!
I used to run a TFTP server on my router that held the decryption keys. As soon as a machine got far enough in the boot sequence to get network access, it would pull the decryption keys from the router. That way a thief would have to steal the router along with the computer, and have the router running when booting up the computer. It works wirelessly, too!
This is a pretty clever solution. Most thieves won’t follow a cable that for all intents looks like a network cable, especially if it disappears into a wall plate or something.
I don’t think most thieves care much about the data on the computer in the first place. Steal hardware, fresh install of Windows on it and straight to the pawn shop.
Agreed. Even just putting a non-Windows/Mac compatible file system on it may have the same effect. They cannot see files when they plug the drive into their PC or Mac, so they probably also just format it.
I’m curious; how would you do it for VMs with an encrypted virtual disk?
Same way.