Two-Step CAPTCHA: Using a Simple Two Step Turing Test to Differentiate between Humans and Bots
Adarsh Baluni, Sayali Gole · International Journal of Computer Applications · 2013
Growth of Internet and its usage has made web services prone to malicious threats by automated scripts or bots."Completely Automated Public Turing Test to tell Computers and Humans Apart", commonly abbreviated as CAPTCHA, is a technique used by web services to differentiate between humans and bots.[1] Most of these techniques are based on recognizing the distorted images of alphanumeric texts that are often not easy to understand by the humans.We put forward a new idea of preventing automated attacks by bots, which asks users to pass through a simple two-step process of authentication.The first step involves recognizing an image from a set of images that best answers to the question associated with this step.The second step involves entering the values associated with the image selected so as to further nullify the probability of a bot attack.