> Now that I've implemented the loop encryption thingy, how hard
> would it be to implement it into the VFS? And at what level?
You might take a look at AT&T's cfs for another, NFS-style approach
at implementing file encryption. CFS' strenght is that it is relativly
portable and also has some kind of key handling. It uses only DES as
encryption but you might hack it to use IDEA, too. CFS is only an
usermode solution but given the performance of DES/IDEA encryption this
isn't a problem.
AT&T's "ammunition" CFS is available on ftp.funet.fi ...
Ralf