Date Added: Dec 2011
Today, approximately all the Internet users have login accounts for Internet sites and these sites require only the registration by human users, but unfortunately some automated computer programs to enter these sites and use their resources through false registration. This paper introduces a new Time-Variant Captcha. In this paper, the authors are not focusing on the effective development of Captcha, but targeting a display of Captcha over the webpage for a fixed time, Captcha replaces itself until the final Captcha is filled by user. Refresh process just work with Captcha and don't affect the web page. So, now, automated program has to cover one more area to breach the Captcha: to determine the final entered Captcha.