# Encrypt with LUKS (Linux Unified Key Setup)

# apt-get install cryptsetup
# luksformat -t ext4 /dev/sdb
# cryptsetup luksDump  /dev/sdb
# cryptsetup open --type luks /dev/sdb luks
# mount /dev/mapper/luks /mnt/luks
# umount /mnt/luks
# cryptsetup close luks