OCR Captcha Alternative for Visually ImpairedUsers

The internet has been playing an increasingly important role in our daily life, with the availability of manyweb services such as email and search engines. However, these are often threatened by attacks fromcomputer programs such as bots. To address this problem, CAPTCHA (Completely Automated Public TuringTest to Tell Computers and Humans Apart) was developed to distinguish between computer programs andhuman users. Although this mechanism offers good security and limits automatic registration to webservices, but many CAPTCHAs are not user friendly and sometimes can pose some challenge to the users,especially visually impaired users. This paper provides an alternative OCR based captcha that can be usedby all the users (including visually impaired users). It would provide better user experience, easy to solve andhard for a bot to crack.