Shared Crypto System gives the user option to effectively
transparently encrypt files on a shared network filesystem,
without directly knowing which communication partner will
open the file, without needing to share a keypair. It uses
Blowfish encryption and one "key" (the passphrase) to
decrypt the files. This prevents the hassle of sharing lots of
keys and choosing which key to use. It also has an option to
recode using a new "key", if for some reason the old key is
no longer trusted.