Introduction to  captcha :

Captcha is a verification method done by machine to human beings called as reverse turning test used by sites to protect from automatic submissions by bots and from spams.

In this paper we will cover introduction to captcha, types of captcha, applications of captcha, prevent comment spam in blogs  and more information.

Students can download reference material captcha presentation,pdf,reports from the download link.

video link for captcha presentation

Computer science students can use captcha concept as seminar topic.