Did you enabled the full disk encryption (LUKS) on Ubuntu 18.04? I would like to share how you can change the LUKS password. LUKS stands for Linux Unified Key Setup developed in 2004 by Clemens Fruhwirth. Similarly, Apple’s macOS have FileVault and BitLocker for Microsoft Windows operating system.
In the terminal you can check the drives or partition with LUKS by using this command
My result looks like this. Your result might differ slightly.
Alternatively, you can verify the partition if it is LUKS by this command.
sudo cryptsetup -v isLuks <device>
Finally, to change the existing full disk encryption (LUKS) passphrase use the following command.
sudo cryptsetup luksChangeKey <device>
The cryptsetup command can help you easily manage your existing LUKS disk drives. Did you know that you can add up to 8 keys on an LUKS? Full disk encryption is really important to secure our valuable data on our hard drives and learning how to manage LUKS is a good thing.