International Journal of Engineering Trends and Technology
CAPTCHA is a challenge-response test most often placed within web forms to determine whether the user is human. The purpose of CAPTCHA is to block automated scripts that post spam content everywhere they can. This paper presents a survey of optical character recognition applications and further focuses on three important applications of optical character recognition, CAPTCHAS. There is a constant need to improve current CAPTCHAs and to develop new CAPTCHAs in order to safely secure against developing programs which can create thousands of e-mail accounts used for malicious purposes, stuff online polls with ballots, and develop worms and viruses contained in emails.