LUKS Encrypted Container

Create a 20Mb file filled with random data: ¹⁾

sudo dd if=/dev/urandom of=encrypted.luks.img iflag=fullblock bs=1M count=20

Switch to root:

sudo -s

Set permissions:

chmod go= encrypted.luks.img

Configure encryption:

cryptsetup --verbose luksFormat encrypted.luks.img
cryptsetup --verbose --use-random luksFormat encrypted.luks.img

Open the encrypted container:

cryptsetup --verbose luksOpen encrypted.luks.img encrypted

Create filesystem:

mkfs.ext4 /dev/mapper/encrypted

Create directory to mount the container:

mkdir /mnt/encrypted

Mount the container:

mount -t ext4 -o journal_checksum /dev/mapper/encrypted /mnt/encrypted

Chown it:

chown chuck: /mnt/encrypted

Set permissions:

chmod go= /mnt/encrypted

Switch back to $USER:

exit

Copy or create your files:

cp /files/to/copy /mnt/encrypted

Switch to root:

sudo -s

Unmount the container:

umount /mnt/encrypted

Close the encrypted container:

cryptsetup luksClose encrypted

Switch back to $USER:

exit

If you want/need to change the password:

sudo cryptsetup luksChangeKey encrypted.luks.img