Hammer feature suggestion

[Sdävtaker]

Hey,
I was using Hammer for a while (10 months) and i found it extremly
usefull (and stable now).
The PFSs are very handfull for administration and backup.
I manage 3 servers with DFBSD right now and 0 makes mirror-copy in 1,
1 in 2 and 2 in 0 so i can ever have a backup of everything just in
case.
I was wondering if there is the possibility to make the PFSs crypt-able.
You pass them the RSA/DSA pair key at mount (mount -key pathToKey
/pfs/cryptedPFS ), the key could be stored in a removable device, like
a usb stick, CDROM or anything else (get it from a server in local
network, i dont know).
I found it usefull for notebooks, you can crypt /home and /var, have a
usb with the key pair, so if someone stole the PC, at least you dont
have to worry about the data.
I was thinking use the keys for crypt at  8MB chunks basis (i had read
hammer has a 8MB chunks allocation in the tree) and code/decode at
use.
I wondering if it is possible to add this feature without big
collaterals, if you think it can be added smoothly and someone can
guide me a little i can try to code it.
Sdav