=== Anti-Captcha ===
Contributors: filiw
Donate link: 
Tags: spam, anti-spam, anti-captcha, captcha, comments, register, login, lost, password, bot, bots, attack, protect 
Requires at least: 2.8.4
Tested up to: 3.0
Stable tag: 20100708

Anti-Captcha is a transparent captcha solution which does not require any end-user interaction

== Description ==

Anti-Captcha is a transparent captcha solution which does not require any end-user interaction.
It is based on a nonce key, which is dynamically inserted using randomly generated (and obfuscated) javascript.

The aim of this plugin is to prevent automated attacks (by bots) on the following WordPress actions:

* Posting comments
* Authenticating
* Registering for a new account
* Requesting a lost password

When a comment is posted without a valid Anti-Captcha token, it shall be *instantly marked as spam*. This way, you can always manually approve this comment in hindsight if it appeared to be sincere.

For more indepth information about the concept and technique see:
[The Anti-Captcha Challenge](http://blog.fili.nl/articles/the-anti-captcha-challenge/)

== Installation ==

To install simply:

1. Upload the 'anti-captcha' folder to the /wp-content/plugins/ directory
1. Activate the plugin through the 'Plugins' menu in WordPress


== Frequently Asked Questions ==

= Is javascript required by the user? =
Yes, however this sounds worse then it is.
Generally, it's frowned upon if you don't write javascript in an unobstructive way.
The reason for this is that some visitors don't support javascript but should still be able to get around your website.

AFAIK there are four types of user-agents not supporting javascript:

* Search-engine spider bots
* Users of a command-line browser (like Lynx)
* Users who actively disabled javascript in their browser
* Mischievous bots trying to spam or hack into your blog

Obviously, search-engines don't need to comment, register or login so they can be ruled out.
Lynx users and users with javascript disabled are likely to be a *very small* percentage of the internet population, who have actively excluded themselves from certain webfeatures. Finally, badly behaving bots, is what the Anti-Captcha plugin is trying to block.


== Screenshots ==

Anti-Captcha is completely transparent.

== Changelog ==

= 20100708 =
* Tested on WordPress version 3.0

= 20100426 =
* Changed error message to be more descriptive
* Changed cookie mechanism to not rely on PHP sessions
* Added 'Back/Forward Cache' prevention
* Removed jQuery dependency
* Tested on WordPress version 2.9.2

= 20090821 =
* First release