Mountain Lion - Are these different ways of encrypting a Time machine backup equivalent? I just setup two backup drives for time machine in two different ways:

1) By clicking the "encrypted" checkbox in the time machine dialogue.
After fininshing the backup, it spent a long time saying "encrypting..."

2) By formatting the drive as HFS+,Journalled,Encrypted using Disk Utility,
and then keeping the the encrypted checkbox on in Time Machine (see note a).

The results are strange.  The time machine preferences says that drive 2 is encrypted,
however 


  diskutil cs list | egrep -i "size|status"


reports 


       Size (Total):       1999702540288 B (2.0 TB)
       Size (Converted):   -none-



The time machine preferences does not say that drive 1 is encrypted, though it too
forever to do so.  Perhaps that's because it's not mounted now.

(a) I also explored approach 2 while turning off the checkbox, thinking this
would cause the material to be encrypted twice.  However it said something
indicating that it would decrypt the drive, so I stopped this.
With option 1 you are encrypting the files, not the drive. Option 2 encrypts the whole drive.