Quick But Secure Comments Registration

I am trying to create a comment registration form, one that would be quick, but secure. For instance, when I choose for my WP site to have a secure registration form, when people need to apply, they are redirected to the WordPress site with the logo to log in. But, if I choose the easier process, then anyone can register, and it wont be as secure.

What I am trying to get at is that I am trying to create a form which makes users think that they are registering for my site, and not through WordPress, and have the sign up process where the user has to fill out a name, password, and their email address, so that they can confirm it’s them, and then they can comment on the site.

Can anybody help me with this, or will this consist of some programming?

Basically, I am trying to make my own sort of “database”, if you will, with the ability to let users create avatars and information about themselves. Is there some sort of tool that can be used through the web host that I am on?