Scratch CAPTCHA - A Novel Touch Scratch Approach to Resolve CAPTCHA Issues

CAPTCHA [1; 2] (Reverse Turing Test) is an authorization test to ensure that response is coming from human. Over the years, its design has been vulnerable to different attacks that utilize the visual appearance of challenge. Therefore, designing a highly robust and usable CAPTCHA that can resist such attacks is highly desirable. The study proposes a novel scheme, named Scratch CAPTCHA. It is based on a new paradigm which emphasizes the notion that strength of the CAPTCHA must be formulated by the secrecy of challenge. We have tested the robustness of our idea against a simple bot attack that successfully emulates human behavior (or actions) but not their intelligence.