HumanCaptcha by Outerbridge

Most captchas are based on the requirement to reproduce a number of randomly-generated characters (which are sometimes blurred, jiggled and/or on a fuzzy background). HumanCaptcha generates a simple question which the user must answer using logical thought. HumanCaptcha is much more accessible than standard captchas (which many people find difficult to read or understand). Visually impaired people are much more likely to be able to use HumanCaptcha than a character-based one.

** Captchas **

Most captchas are based on the requirement to reproduce a number of randomly-generated characters (which are sometimes blurred, jiggled and/or on a fuzzy background). HumanCaptcha generates a simple question which the user must answer using logical thought. HumanCaptcha is much more accessible than standard captchas, which many people find difficult to read or understand. Visually impaired people are more likely to be able to use HumanCaptcha than a character-based one.

CAPTCHAs are useful for improving security in a number of situations, for example:

1. Reducing Comment Spam in Blogs
   Most bloggers will have come across programs that submit spam comments, often with the aim of improving the search engine ranking of a website. By using a CAPTCHA, only humans can enter comments on your blog, and people do not need to sign up before they enter a comment.

2. Protecting Email Addresses From Scrapers
   Spammers crawl the web looking for e-mail addresses rendered in text. CAPTCHAs can hide your e-mail address from web scrapers, by requiring users to solve a CAPTCHA before revealing your e-mail.

3. Deterring Viruses, Worms and Spam
   CAPTCHAs may reduce the likelihood of e-mailed viruses, worms and spam, by only accepting an e-mail if it has been established that there is a human behind the sending computer.

Credits

Many thanks to:
TH90 (https://wordpress.org/support/profile/th90) of MPW D&D for the Persian translation files (fa_IR). Language: Persian, Country: Iran.
Dayl (http://dayl.ru) in Санкт-Петербург for the Russian translation files. Language: Russian, Country: Russia.