JGC Google reCAPTCHA is a WordPress Plugin by GalussoThemes and Juan de la Cruz that adds Google reCAPTCHA to forms of your WordPress site and protect it from spam and abuse while letting real people pass through.
You can enable/disable Google reCAPTCHA for:
Login form.
Register form.
Lost password form.
Comments form.
Download: https://wordpress.org/plugins/jgc-google-recaptcha/