saminar report on captcha
[size=medium[/font][/size]][font=Times New Roman]

Abstract

CAPTCHA is an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart." It is a type of challenge-response test used in computing to ensure that the response is not generated by a computer. The process usually involves one computer (a server) asking a user to complete a simple test which the computer is able to generate and grade. Because other computers are unable to solve the CAPTCHA, any user entering a correct solution is presumed to be human. A common type of CAPTCHA requires that the user type letters or digits from a distorted image that appears on the screen.

This concept is used by all the big companies over internet Google, yahoo or facebook (name any).So what are these CAPTCHAS? And what are their possible applications? This is what we cover in our presentation.

Types of CAPTCHA

Text based
Gimpy, ez-gimpy
Gimpy-r, Google CAPTCHA
Simards HIP (MSN)
Graphic based
Bongo
Pix
Audio based
Application of CAPTCHA

Online polls
Search engine bots
Worms and spams
Search Engine Bots
Prevent dictionary attacks
Preventing Comment Spam in Blogs
Protecting Website Registration
Protecting Email Addresses From Scrapers
CAPTCHAS are any software that distinguishes human and machine. Research in CAPTCHAS implies advancement in AI making computers understand how human thinks.

Internet companies are making billions of dollars every year, their security and services quality matters and so does the advancement in CAPTCHA technology.

Different methods of CAPTCHAS are being studied but new ideas like ReCAPTCHA using human time on internet is amazing.