Captcha Bank is an easy to use wordpress security plugin to prevent spam on your site while letting real people pass through with ease. It's more
This plugin allows you to implement super security captcha form into web forms.
WP Light Captcha is very simple and lightweight captcha plugins for your WordPress site.You can protect unwanted login request from hackers.
Captcha image for registration page, customize according to your theme.
This plugin allows you to implement Google Captcha (reCAPTCHA) into web forms.