How to create an online installer talking to an HTTPS server?

Hello,

i remember seeing in old QtIFW docs occurrences of private / public keys, but i can't seem to find this article anymore. At the time i found the article, i was only gathering knowledge about IFW, and right now as i'm trying to use the SDK, i can't find this article anymore...
So i tried to set up an HTTPS repository with no luck ("HTTPS scheme not supported" displays in red when running the installer). So i'm wondering, is there a way to do this? It would be especially interesting, when distributing an installer for a beta product to a customer who has a password for the repository, to avoid people sniffing the password in clear. Right now i have solved the problem by giving directions to my customers to use putty to tunnel to my HTTP server, and i use a temporary installer set to a repository URL of localhost:10443, but for non tech-customers, it's a real pain to set up.

Any directions / ideas?

Thank you,
Pierre.