captcha not showing

I have wordpress version 3.7.1
installed Version 1.15 of wp2pgpmail
I use the free cloud flare service
My laptop is running OS10.9
I have a self hosted blog on wpengine

I dug in to the plugin and it says it required GD Library.
do I need to install something else to make the plugin work?

had to remove the comment for my version of pgp for the public key to validate.
next I entered the short code [wp2pgpmail] in the page using the text edit tab
updated page and then saw the catch image was broken.

So opened the debug window of safari 7 to inspect the element of the broken cattcha image

here is some of the code returned that I copied

<img src=”http://nko.org/wp-content/plugins/wp2pgpmail/phpcaptcha/securimage_show.php&#8221; id=”captcha” alt=””>

when I looked at the error console I found this

Failed to load resource: the server responded with a status of 403 (Forbidden)
http://nko.org/wp-content/plugins/wp2pgpmail/phpcaptcha/securimage_show.php

[Warning] Invalid CSS property declaration at: * (noticons.css, line 1, x3)
[Warning] Invalid CSS property declaration at: ; (wpcom-admin-bar.css, line 6

I deleted the short code from page since it is non functional

please help !

http://wordpress.org/plugins/wp2pgpmail/