a safe X terminal

[Dumas Patrice <dumas centre-cired fr>]

Hi,
I would like to setup some X terminals, with redhat 7.0. But I also would like
to have a good security. So, I would like an encrypted connection between the X
terminals and the application server, such that a sniffer can't get the
passwords for example, and also a reasonable security for allowing only some
clients to connect.

I have read a lot of things about XDMPC, but it seems it can't be really
secured.
I have also read some things about ssh and tcp forwarding, but it seems that it
isn't possible with it to emulate an X terminal setup. 

Is this right, or wrong ?
Does someone have links to documents explaining how to do what I want to ?

Thanks in advance.

Pat