Completely Automated Public Turing test to tell Computers and Human Apart..
It s kind of word verification test... to differentiate human and computers.
Reason for having CAPTCHA:
- To prevent 1)malicious attacks
2)Spammers
- To avoid automated software bots..
(Automated software bots-computer automatically created huge no. of large requests to server which in turn cause, degrade the server quality)
Various forms of CAPTCHA:
- It is distorted or randomly stretched characters ..
- It is rely on images also, four images present in that three of them contain animal picture, one contain flower. We have to choose it.
- Another audio challenge which contains some sound with noisy effect..
Human beings only able to identify patterns of CAPTCHA
Pros:
One Artificial intelligence algorithm is found until to train the real intelligence to machine to break
CAPTCHA
Applications of CAPTCHA:
1)Online polls
2)Registration forms
3)Free account creation process in Gmail,Ymail,hotmail etc
