================ crypto files
http://www.ppcnerds.org/displayarticle186.html
apt-get install loop-aes-utils

apt-get install cryptsetup

modprobe aes

which will load the aes routines
Assume that the file that will act as a filesystem for our loopback device is
called crloop: it has a size of 640 MB and i created it typing
dd if=/dev/zero of=/home/marco/crloop bs=1M count=640
Once you created this and you installed all the user-space tools and the kernel
modules are in place, you're ready to go
mount -t ext2 /dev/loop0 /media/cryptovolume -oencryption=aes
==============
cryptsetup --verbose --verify-passphrase -c aes-cbc-plain luksFormat /dev/sda2
cryptsetup luksOpen /dev/sda2 sda2

ls -l /dev/mapper

mkfs.ext3 /dev/mapper/sda2
mkdir /home/raffi/crypted
mount /dev/mapper/sda1  /home/raffi/crypted

---------- /etc/fstab
/dev/mapper/sda2  /home/raffi/crypto  ext3 user,atime,noauto,rw,dev,exec,suid   0 0

chown raffi:raffi /home/raffi/crypto
cryptsetup luksClose sda2