Localized CAPTCHA testing on users and farms

Abstract

The paper describes the experience of resisting the large-scale solving of CAPTCHA through the CAPTCHA-farms and presents the results of experimenting with different types of textual CAPTCHA on the farm worker and casual user crowds. Localization of CAPTCHA led to cutting twice the absolute volume of CAPTCHA parsing, but introducing the semantics into the test complicated it to casual users and was not found promising.