encrypted root filesystem

[paul@gilbertson.biz]

Is there any cryptsetup hook to encrypt the root file system for Debian 
live builds?  Some way to encrypt the live media itself as part of the 
boot process? Of course I'm not talking about encrypted persistence 
which is documented nicely in the debian live manual. Just to be clear I 
am talking about having the read only root file system encrypted with 
cryptsetup since the losetup method of loop-aes has been removed and 
there is no longer a  lb config -e (encryption) option any more.

Thanks,

paul