Abstract
Bots are programs that crawl through the web site and make auto registrations. CAPTCHAs, using Latin script, are widely used to prevent automated bots from abusing online services on the World Wide Web. However, many of the existing English based CAPTCHAs have some inherent problems and cannot assure the security of these websites. This paper proposes a method that focuses on the use of Arabic script in the generation of CAPTCHA. The proposed scheme uses specific Arabic font types in CAPTCHA generation. Such CAPTCHA exploits the limitations of Arabic OCRs in reading Arabic text. The proposed scheme is beneficial in Arabic speaking countries and is very useful in protecting internet resources. A survey has been conducted to find the usability of the scheme, which was satisfactory. In addition, experiments were carried out to find the robustness of the scheme against OCR. The results were encouraging. Moreover, a comparative study of our CAPTCHA and Persian CAPTCHA scheme shows its advancement over Persian CAPTCHA.