Changing Trends in CAPTCHA Breaking Mechanisms for Graphical Text Based CAPTCHA

CAPTCHA determines difference between human and machine. Thus is widely used for Web programs over Internet. It is the security entrance and provides permission of access when it tests credentials depending upon its need. The versatility of CAPTCHA depends upon its firmness to withstand attacks. Better CAPTCHA‘s are more secure for implementation. To breach the security mechanism provided by CAPTCHA it needs to be break in order to achieve intrusion. Breaking CAPTCHA involves number of mechanisms which when fallowed properly acquire quality result. In this research procure we presented the various breaking mechanism on Graphical text based CAPTCHA which are categorised under five stages and touted out the analysis on the basis of these approaches. We have recollected various mechanisms used up in breaking text based graphical CAPTCHA