luks

install a package

$ sudo apt install cryptsetup

format

$ sudo cryptsetup luksFormat /dev/md0 
$ sudo cryptsetup luksDump /dev/md0

open

$ sudo cryptsetup open /dev/md0 cryptfs
$ sudo cryptsetup status cryptfs

open tcrypt device

$ sudo cryptsetup open --type tcrypt /dev/md0

format mount

$ sudo mkfs -t ext4 /dev/mapper/cryptfs 
$ sudo mount /dev/mapper/cryptfs /mnt
$ df -h /mnt

umount and close

$ sudo umount /mnt 
$ sudo cryptsetup close cryptfs