I could, but I can also enable it for the whole site, anyway in both cases I need to install and configure a certificate on the server

You can use the https for the login process only

By the way, I still have to add HTTPS to the site, as this becomes a security must-have with people connecting to public wifi networks.
Now that browsers clearly indicate that non-HTTPS sites are "unsafe" when you have to enter a password, that does not looks good on IMCDb

Hi,
A small (and mostly not visible) update: I copied an improvement from the next version of the site to the current version, to improve handling of cookies and passwords.
If you notice anything not working or an error appearing at some time, please report it here or contact me by e-mail (address = contact at imcdb.org)
the only visible thing should be that you had to log in again.
Also, if you changed your password in the last few hours, the change may have been lost (old password active again).