ImHuman – a humanized captcha WordPress Plugin »

ImHuman is a new way of asking “are you a human?” question to your website visitors. It is designed to be easy, fun, secure and user friendly than most of the other captcha systems. Security and fun grows a little bit more everyday because it uses the ImHuman globalized API and you do not need to worry about anything. Supports AJAX comments, multilanguage, customizations and eliminates security drawbacks from browser cache.

Features:

* Automatically insert ImHuman security check to any page
* AJAX support for comments without any hack or modification
* Uses global wordpress errors in a fancy way instead of die
* Option to skip check for registered members
* Recreation of humanizer grid at every failed attempt
* AJAXed comments will function even though grid is not displayed
* Multilanguage Support
* Cache and Back key support
* Works seemlesly with mobile browsers. Specially Iphone.
* Plugin will only activate itself if the current url is a page or post
* It acts within the boundaries of “is comments allowed”
* You can tweak your API user and keys from administration page
* Tweaks to show how many rows, columns and selection options are configured from plugin settings page also
* Requires PHP5 and JQuery to be existant
* Security checks are done within the boundaries of wordpress, no extra connection required
*

Detailed error and debug reporting in the event of an error instead of blocking the whole wordpress execution
*

Support
* Version History
* FAQ
* Installation

Tags: security, spam, comments, admin, posts, Post, AJAX, captcha, user interface, plugin, security check

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Contact Form Captcha WordPress Plugin »

Easy to use contact form with captcha enabled. Displays nice looking validation errors and success messages on respective failure and success while sending the mail. The contact form can also have content of your own. The content which will be displayed at the begining of the form and then the form itself.
Tags: captcha, form, contact

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Really Simple CAPTCHA WordPress Plugin »

Really Simple CAPTCHA does not work alone and is intended to work with other plugins. It is originally created for Contact Form 7, however, you can use it with your own plugin.

Note: This product is “really simple” as its name suggests, i.e., it is not strongly secure. If you need perfect security, you should try other solutions.
How does it work?

Really Simple CAPTCHA does not use PHP “Sessions” for storing states, unlike many other PHP CAPTCHA solutions, but stores them as temporary files. This allows you to embed it into WordPress without worrying about conflicts.

When you generate a CAPTCHA, Really Simple CAPTCHA creates two files for it; one is an image file of CAPTCHA, and the other is a PHP file which returns the correct answer to the CAPTCHA.

The two files have the same (random) prefix in their file names, for example, “a7hk3ux8p.png” and “a7hk3ux8p.php.” In this case, for example, when the respondent answers “K5GF” as an answer to the “a7hk3ux8p.png” image, then Really Simple CAPTCHA runs “a7hk3ux8p.php” code and tests the answer against the return value it receives. If the return value is “K5GF,” the two match, and the answer is confirmed as correct.
How to use with your plugin

First, create an instance of ReallySimpleCaptcha class:

$captcha_instance = new ReallySimpleCaptcha();

You can change the instance variables as you wish.

// Change the background color of CAPTCHA image to black
$captcha_instance->bg = array(0, 0, 0);

See really-simple-captcha.php if you are interested in other variables.

Generate a random word for CAPTCHA.

$word = $captcha_instance->generate_random_word();

Generate an image file and a PHP code file in the temporary directory.

$prefix = mt_rand();
$captcha_instance->generate_image($prefix, $word);

Then, show the image and get an answer from respondent.

Check the correctness of the answer.

$correct = $captcha_instance->check($prefix, $the_answer_from_respondent);

If the $correct is true, go ahead. Otherwise, block the respondent — as it would appear not to be human.

And last, remove the temporary image and PHP files, as they are no longer in use.

$captcha_instance->remove($prefix);

That’s all.

If you wish to see a live sample of this, you can try Contact Form 7.
Tags: captcha

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Captcha The Dog WordPress Plugin »

Photo Captcha with user defined images to reduce the spambot prize/payload to one website at a time. Creating a new captcha puzzle one new image at a time. Building a new spambot for each website with unique user defined images does not make financial sense for the spammer.

A captcha with “Which one of these things is not like the other?” puzzle.

Version history: – 1 may 2009: created – 5 may 2009: public released – 7 may 2009: admin does not need to use captcha, catches php.ini file error
Tags: spam, captcha, captcha the dog

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wp-num-captcha WordPress Plugin »

Adds Numerical addition CAPTCHA anti-spam methods to WordPress on the comment form. In order to post comments, users will have to type in the phrase shown on the addition. This can help prevent spam from automated bots.

V1.1 * fix : Modified interface pos.
Tags: spam, comments

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Raz-Captcha WordPress Plugin »

Prevent registration spam and bots login by adding custom captcha tests in the registration page and/or login page

Featuring 5 different and customizable captcha algorithms with possibility to set your own random characters font, styles, colors background and more
For a working demo se login and register pages from the author home page
Tags: against spam-bots, login, register, anti-spam, captcha, spam-bots, turing test, image, generator, random image

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Simple CAPTCHA WordPress Plugin »

A CAPTCHA for your comment system to prevent unwanted spams. Prevent automated spams by bots and most important naughty peoples. It’s simple and yet secure.
Tags: security, image, captcha, simple captcha

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WP Captcha-Free WordPress Plugin »

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
Tags: tbt, token, hash, captcha, comment, comments, anti-spam, antispam, AJAX, spam

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CAPTCHA-Godfather WordPress Plugin »

This plug-in protects the form for posting comments from spam by 4 ways; CAPTCHA code, Session ID (which is different from PHPSESSID), Timestamp, IP Address. Also allows the webmaster to choose between fonts.
Tags: protection, spam, captcha

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Security Captcha WordPress Plugin »

Security Captcha es un sistema para prevenir spam de cualquier tito, tanto por personas como por scripts creados por personas.
Tags: generator, turing test, spam-bots, random image, anti-spam, register, login, against spam-bots, wp security, Security captcha, security, image, captcha

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