CAPTCHA

Captcha stands for "Completely Automated Public Turing test to tell Computers and Humans Apart". It is a challenge-response test used in account creation or user log on to determine whether or not the user is human.

• CAPTCHA on Wikipedia: http://3020mby0g6ppvnduhkae4.roads-uae.org/wiki/Captcha
• CAPTCHA Project: http://d8ngmj92xucvxkduhhuxm.roads-uae.org/
• Free CAPTCHA Service: http://6xq7e957rk5kcnr.roads-uae.org
• CPAN query on CAPTCHA: http://egjx4j92uuzx6zm5.roads-uae.org/search?query=captcha&mode=all
• Perl implementation: http://46a20n82x5dxcnpgykyx09m1cr.roads-uae.org/hv/en.htm

TWiki related:

• VisualConfirmPlugin - CAPTCHA for TWiki registration
• CaptchaPlugin - VisualConfirmPlugin updated for Dakar

-- Contributors: PeterThoeny, WillNorris - 16 Jul 2006

http://f0cjabdqw2vub2ygt32g.roads-uae.org/yro/04/01/28/1344207.shtml describes an interesting realtime technique for circumventing CAPTCHA.

-- WillNorris - 18 Apr 2005

If you plan to code a CAPTCHA solution for TWiki, make sure it will destroy sessions afterwards... http://d8ngmj82fjkh005rhj5vevqm1r.roads-uae.org/cm_breaking_captcha_115.php

-- AlsterWassermann - 23 May 2005