Uncover impact factors of text-based CAPTCHA identification

Presently, CAPTCHA is an important mechanism to gain access to the required system. However, there are some difficulties for users in typing CAPTCHA although they are authorized persons. Since the Text-based CAPTCHA is the most popular mechanism amongst all the CAPTCHA techniques, the difficulties of this text-based are studied and drawn out. The results of this study have shown that the presented character(s), genders of users, and their educational background are some of the important factors determining the correctness of CAPTCHA typing by its users. Therefore, generating a Text-based CAPTCHA must use the appropriate character(s), that also combining with the educational background and genders of the users.