WP Captcha-Free

WP Captcha-Free blocks automated comment spam without resorting to CAPTCHAs. It does so by validating a hash based on time (and some other parameters) using AJAX when the form is posted. Comments posted via automated means will not have a hash or will have an expired hash and will be rejected. Unlike using a captcha, this does not place any burden on the commenter. Features

1. Ensures that your commenters are human without inconviencing them with CAPTCHAs, challenge questions, etc.
2. The plugin is very simple and adds almost zero overhead. You will notice its presence only by the absence of spam.
3. Use of AJAX makes it compatible with all cache plugins (including WP-Cache) and adds another layer of security.
4. Works out of the box without any configuration, setup, or editing .php files.

How It Works WP Captcha-Free generates a hash (aka token) based on several parameters like time (with a some cushion), post id, IP address, and browser user-agent which should not change between requests (within a short period of say a few seconds). When the comment form is posted the plugin uses ajax to get a hash value and adds it to a hidden field. On the server side it verifies if the hash is valid or not. It uses adds random salt to the hash so that it cannot be guessed. A combination of a time based hash and javascript (ajax) makes it almost impossible for any bot to bypass. Feedback Please let me know what you think about the plugin and any suggestions you may have. If you use the plugin please rate it. If it doesn't work for you do let me know so I can fix it. Post Feedback