Webvanta now provides SSL (https) secure connections on login pages. This keeps anyone who may be watching net traffic from snooping on your password.
To use SSL, the site must provide a security certificate. This has nothing to do with the actual encryption, but rather is used to verify that the site you're accessing is the one you expect.
Our security certificate covers www.webvanta.com, and all subdomains (such as mysite.webvanta.com). But it cannot cover other domains, such as www.mysite.com. So if you have your site set up with its own custom domain, and you log in via that domain (www.mysite.com/login), you will see a stern warning from your browser that the security certificate is invalid. You can safely accept the exception and proceed.
If you want to avoid seeing the warning, you can log in via your site's Webvanta subdomain (mysite.webvanta.com/login).
In the future, we plan to offer the option for you to purchase a security certificate for your domain, so you can use SSL at your custom domain name without seeing any warnings.