ASCII CAPTCHA

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Classes of Debug

ASCII CAPTCHA

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Name:	ASCII CAPTCHA Support forum
Base name:	`ascii_captcha`
Description:	CAPTCHA validation using ASCII art text
Related classes:	CAPTCHA, ascii, php captcha, fonts, CAPTCHA class, ASCII ART, captcha bypass, random number
Version:	`-`
PHP version:	`3.0`
License:	The PHP License
All time users:	3082 users
All time rank:	977
Week users:	12 users
Week rank:	206

	Author

Name:	Debug `<e-mail contact>`
Packages:	4 Browse all classes by Debug
Country:	United States - PHP jobs in United States
Age:	22
All time rank:	456	52 in United States
Week rank:	159	13 in United States

Innovation award

Nominee: 4x

	Detailed description

This class can be used to perform CAPTCHA validation, display text letters using ASCII art fonts.

It generates a CAPTCHA validation text string with random letters and then renders that text as an ASCII art string with multiple lines that represent the validation text with some distortion and noise characters.

The random validation text and the rendered text are returned as strings.

	Groups		User ratings		Trackback		Applications		Files

	Groups

Text processing	Manipulating and validating text data	View top rated classes
Validation	Validation algorithms	View top rated classes
Security	Security protection and attack detection	View top rated classes

	Innovation Award

PHP Programming Innovation award nominee

May 2008
Number 2

CAPTCHA validation is a way to make it more difficult the use of robot scripts to impersonate real users accessing sites.

Many techniques have been developed to implement different variants of CAPTCHA validation, but some can easily be defeated with more sophisticated robots.

This class provides different approach by using text rendered as ASCII art instead of using the usual obfuscated images. This way, existing CAPTCHA breaking robots would need to be adapted to bypass this solution.

Manuel Lemos

	User ratings

Ratings	Utility	Consistency	Documentation	Examples	Tests	Videos	Overall	Rank
All time:	`Sufficient (79.2%)`	`Sufficient (79.2%)`	`Sufficient (75.0%)`	`-`	`-`	`-`	`Not sure (55.0%)`	1160
Month:	Not yet rated by the users

	Trackback links

Link	Description
Ca(p)tch(a) me	Captchas sind eine feine Sache...

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	Applications that use this class

No application links were specified for this class.

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

	Files

File	Role	Description
`documentation.html`	Doc.	Documentation
`ascii_captcha.class.php`	Class	The main ASCII CAPTCHA class
`example.html`	Output	Example code and output

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