FIle transfer over network - with Pyro?

[Nathan Huesken]

Hi,

I am writing a network application which needs from time to time do
file transfer (I am writing the server as well as the client).
For simple network messages, I use pyro because it is very comfortable.
But I suspect, that doing a file transfer is very inefficient over
pyro, am I right (the files are pretty big)?

I somehow need to ensure, that the client requesting a file transfer is
the same client getting the file. So some sort of authentication is
needed.

What library would you use to do the file transfer?
Regards,
Nathan