Looking for way to encrypt and securley share files

I posed a similar topic over on the Buddypress forums. I was thinking about some type of replacement for a secure messaging gateway, but so far I’ve just tested a few different things. I’m close with a combination of plugins: private files, wordpress download manager and either absolute privacy or private wp.

I’n not sure about encrypting when the file hits the server but the private sharing of files could be pretty close with some type plugin combos.