Class: Animated CAPTCHA (ocr, gif, animated GIF)

Name:	Animated CAPTCHA Support forum
Base name:	`animatedcaptcha`
Description:	CAPTCHA validation using animated math expressions
Search tags:	ocr, gif, animated GIF
Version:	`1.1`
Required PHP version:	`4.0`
License:	GNU Lesser General Public License (LGPL)
All time users:	3209 users
All time rank:	497
Week users:	35 users
Week rank:	136

	Supplied by		Groups		Detailed description

	User ratings		Trackback		Applications		Related links		Files

Supplied by:

Name:	Josh Storz `<e-mail contact>`
Published packages:	1
Country:	United States - PHP jobs in United States
Home page:	`http://querythe.net/`
Age:	???
All time rank:	495
Week rank:	183

Browse this author's classes

Innovation Award:

June 2007
Number 6

CAPTCHA validation is being used everywhere on the Internet to make it difficult for robots to access sites that should be accessed only by real human user beings.

One of the problems is that most solutions are based on images that show validation text that is easy to guess using common OCR (optical character recognition) programs.

This class provides a CAPTCHA alternative that uses animated images. In each animation frame, it is presented a number or the symbol of a simple math operation that the users must solve to pass the validation tests.

This solution raises the difficulty to robots in comparison to other CAPTCHA solutions that are easier to defeat by the current generation of robots.

Manuel Lemos

Groups:

Graphics	Colors, images, charts and picture formats	View top rated classes
Validation	Validation algorithms	View top rated classes
Security	Security protection and attack detection	View top rated classes

Detailed description:

This class can be used to perform CAPTCHA validation presenting to the users simple mathematical expressions as a sequence of animated pictures to make it difficult for robots to pass a form being validated.

It generates an animated GIF image that displays a mathematical expression of a simple operation between two random numbers, like sum, subtraction and multiplication.

The numbers and the operation are stored in session variables for posterior verification.

User ratings:

Ratings	Utility	Consistency	Documentation	Examples	Tests	Videos	Overall	Rank
All time:	`Good (84.6%)`	`Good (88.5%)`	`Good (86.5%)`	`Good (86.5%)`	`-`	`-`	`Sufficient (68.5%)`	190
Month:	Not yet rated by the users

Trackback links:

Link	Description
Animated Captcha - Image Validation	The easiest way to keep spam bots away...
Animierte Captcha Grafik [php]	Der Entwickler Josh Storz hat eine durchaus Interesannte Captcha-Grafik Entwickelt...
Comment Spam Killer - Class: Animated CAPTCHA (CAPTCHA, validation, ocr, animated GIF) - PHP	This class can be used to perform CAPTCHA validation presenting to the users simple mathematical...

Latest blog trackback links

Applications that use this class:

Link	Description
STAEP Job Postings	security enhancement for job posting form.
healthy women	captcha in contact form
American School Directory	Comment script for each school uses Animated CAPTCHA

If you know an application of this package, send a message to the author to add a link here.

Related links:

Link Description

Animated Gif Captcha Resources The official launch page of Animated Gif Captcha

Files:

File	Role	Description
`example.php`	Example	Working Example
`frames`
`0.gif`	Icon	readme
`1.gif`	Icon	readme
`2.gif`	Icon	readme
`3.gif`	Icon	readme
`4.gif`	Icon	readme
`5.gif`	Icon	readme
`6.gif`	Icon	readme
`7.gif`	Icon	readme
`8.gif`	Icon	readme
`9.gif`	Icon	readme
`equals.gif`	Icon	gif frame
`minus.gif`	Icon	gif frame
`plus.gif`	Icon	gif frame
`solve.gif`	Icon	gif frame
`times.gif`	Icon	gif frame
`GIFEncoder.class.php`	Class	GIFEncoder class
`index.php`	Example	Main Function - Displays picture & sets session
`OOP4.php`	Class	OOP4
`OOP5.php`	Class	OOP5
`readme.txt`	Doc.	readme

Download all files: animatedcaptcha.tar.gz animatedcaptcha.zip

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Class: Animated CAPTCHA