[Zope] How do I encrypt files in the ZODB

[grissom@qwickconnect.net]

I recently finished my first project in Zope! A file
managements system with it's own admin screens.

I have recently received requirements for the next version
in which the client is asking that the contractors have
access to everything but the PDFs that have been uploaded.
I know that I could encrypt the PDFs before that they are
uploaded but the secretaries that do it it have a hard
enough time just creating PDFs.

This leads me to my subject. How do I encrypt files in the
ZODB? With regards to just PDFs.

Something in Python?
A product that I missed?
A How To that I missed?
Upload the files to a external file system that is
encrypted?

Any sugestions, feedback and general ideas are appreciated.

Rob G.