dd if=/dev/urandom of=testfile bs=1M count=10
sudo losetup /dev/loop0 testfile 

sudo cryptsetup create crypto /dev/loop0

(asks for passphrase)

sudo mkfs.ext2 /dev/mapper/crypto 
sudo mount /dev/mapper/crypto /crypt/

sudo umount /crypt/
sudo cryptsetup remove /dev/mapper/crypto 

works a little differently with an actual partition… guess it would be

sudo cryptsetup create crypto /dev/sdb1

(asks for passphrase)

sudo mkfs.ext2 /dev/mapper/crypto 
sudo mount /dev/mapper/crypto /crypt/

sudo umount /crypt/
sudo cryptsetup remove /dev/mapper/crypto 

---

this seems to keep the video intact for the most part… i.e.,

cp Entourage.S06E11.HDTV.XviD-NoTV.avi ~/Documents

560  ls -al
561  sudo losetup /dev/loop0 Entourage.S06E11.HDTV.XviD-NoTV.avi -o 10000000
562  sudo cryptsetup create entourage /dev/loop0
563  sudo mkfs.xfs /dev/mapper/entourage 
564  ls /crypt/
565  sudo mount /dev/mapper/entourage /crypt/
566  ls /crypt/
567  ls -al
568  ls /crypt/
569  ls /crypt/ -al
570  cd /crypt/
571  ls
572  cp /home/mmm/Desktop/junk.odb .
573  sudo cp /home/mmm/Desktop/junk.odb .
574  sudo chown mmm.mmm junk.odb 
575  ls -al
576  cd /
577  cd
578  cd Documents/
579  ls
580  ls -al
581  vlc Entourage.S06E11.HDTV.XviD-NoTV.avi 
582  ls
583  mount
584  sudo umount /crypt/
585  sudo cryptsetup remove /dev/mapper/entourage 
586  sudo losetup -d /dev/loop0 
587  sudo losetup 
588  sudo losetup -a
589  ls
590  history