Interactive Handwritten and Text-Based Handwritten Arabic CAPTCHA Schemes for Mobile Devices: A Comparative Study

CAPTCHA tests (Completely Automated Public Turing test to tell Computer and Humans Apart) are used by many services and websites. Recently, researchers have proposed interactive handwritten and text-based handwritten Arabic CAPTCHA schemes. The former scheme presents a handwritten CAPTCHA image, then requests users to select the joints between Arabic letters. In the latter scheme, a new generator of Arabic handwritten CAPTCHA images is developed, once the image is generated, the user is asked to type the letters shown in the image. Although both of them have shown promising results, this experimental study compares them in terms of security and usability for mobile device applications. The results demonstrated that the interactive scheme performs better than the text-based handwritten scheme in both usability and security.