I was thinking about this some time ago (then forgot about it).
I came to the conclusion that a header was required in the file
to indicate encryption, the extension on the file does not change.
Hence the file is automatically decrypted (or user prompted) then
the appropriate hilighting is applied based on the extension as
per a regular file.
Thomas Hundt wrote:
> I've been running the 3/22/00 release, in the hopes that perhaps the crypto
> functionality has been made easier to use... but it doesn't seem to be.
> There's still no way at all to open an encrypted file from the shell prompt
> without having it come up scrambled. I did find the 'find-cfile' command
> to open such a file once in the program, so that is helpful. (Just so you
> know, what I usually do is set up icons to open various files, including
> some that are encrypted. With pre-Jasspa versions, one could use a '-k'
> flag on the commandline to specify an encryption key... this is not totally
> safe, esp. on Unix machines.)
> A nice behavior would be to detect an encrypted file (given on the
> commandline) upon load, and prompt the user for a key, and then open the
> file. It would be OK if this were done via file extension (e.g., '.txc').
> I have been doing some experimenting in my .emf files but haven't gotten
> this to work yet.