For the example CAPTCHA challenges, correct responses can be 'spread' and 'play' or 'cut' and 'amplify', etc., as intuition would suggest.
Egglue CAPTCHA Features
- CAPTCHA challenges require only basic intuitions about the world.
- The distinct CAPTCHA challenges and layout cannot be handled by typical spam bots.
- Different from conventional CAPTCHA, visitors are free to use any words deemed fit.
Unlike other CAPTCHA web services, Egglue CAPTCHA does not require registration.
The Egglue CAPTCHA module requires the CAPTCHA module version 6.x-2.0 or higher.
So, what is a CAPTCHA?
CAPTCHA is often used to ensure that the visitor is a human and not a spam bot. CMS generate content, so Drupal sites are vulnerable to automated spam. However, most CAPTCHA are not accessible. There are several kinds of CAPTCHA available:
- Image CAPTCHA -- Scalable and simple to use, but if the letters in the CAPTCHA are not distorted enough, they can be cracked by OCR techniques; if they are too distorted, visitors can't read. Image CAPTCHA is slowly being replaced by other CAPTCHA.
- Math-based CAPTCHA -- Uses a simple interface and simple to use, but not scalable because most spam bots can parse the CAPTCHA questions.
- Other text-based CAPTCHA -- Most text-based CAPTCHA are also quite simple, but they provide about 4 solution candidates, giving brute force spam a success rate of 1 in 4.
- (Open) Semantic CAPTCHA -- Scalable and intuitive, but they are rare. The CAPTCHA generation is unsupervised, so they are generally hard to build. <-- This is where Egglue belongs.