On Fri, 05 Dec 2003 18:35:55 MST, Pat LaVarre said:

> Suppose we wish to encrypt the files on a disc or disk or drive that we
> carry from one computer to another.
> 
> Where else can the encryption go, if not "down to the file system"?

It could also be above the filesystem, a la PGP, or below the file system,
a la encrypted loopback.  Other options, such as steganography and "purloined
letter" schemes, are also at least theoretically possible, if not totally workable.