You should be able to open a socket connection (all types are supported) and then stream the data using an encryption module.
For socket connections check out the
IO::Socket or
Socket modules. Also read the
perlipc manual page for Perl Interprocess Communication.
For encryption check out one of the many "Crypt::" modules. I found the best way to check them out was to run the "ppm3" package manager from the command line and then search ("s crypt") for crypt modules, install them and read them. There are many variations and encryptions levels, some government standard. Some allow for fragmented streaming that then piece it all back together on the other end.
I've also downloaded a few quick tutorials on how to write sockets, which are a great kickstart. I'll have to dig them up. Email me if you want a copy. Also you can't go past the invaluable article
An Advanced 4_4BSD Interprocess Communication Tutorial Its written for C but gives you the principles for sockets
Not sure about the form authentication side of things but I hope that helps with the encrypted data via http problem side of it
Dean
crabbdean at yahoo.com.au