Linux Disk Encrption using Device Mapper, cryptsetup frontend and Linux Unified Key Setup LUKS (on disk format).

•  dm-crypt:
  • https://www.kernel.org/doc/Documentation/device-mapper/dm-crypt.txt 
  • https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt
  • dmsetup
• cryptsetup and LUKS:
  • https://gitlab.com/cryptsetup/cryptsetup/

Setup:

cryptsetup -y -v luksFormat /dev/sdb1
cryptsetup luksOpen /dev/sdb1 foo
cryptsetup status foo -v

Test:

cryptsetup --test-passphrase open /dev/sdb1 # (non-LUKS)

cryptsetup luksOpen --test-passphrase /dev/sdb1
cryptsetup isLuks /dev/sdb1 && echo IMaLUKS
cryptsetup luksDump /dev/sdb1

Change:

(asks current passphase first)

cryptsetup -y luksChangeKey <target device> -S <target key slot number>
cryptsetup -y luksChangeKey /dev/sdb1 -S 1

Or use gui gnome-disks:

• Disks (gnome-disks)
• 1.0TB Hard Disk
• Volumes: “Partition 1 1.0 TB LUKS”
• Cogs/wheels

Add/remove key:

sudo cryptsetup -y luksAddKey ENCRYPTED_PARTITION
sudo cryptsetup luksRemoveKey ENCRYPTED_PARTITION

Various:

dmsetup ls --tree
lsblk
lsblk --fs