Reviewing Effectiveness of CAPTCHA

International Journal of Computer Trends and Technology (IJCTT)          
© - May Issue 2013 by IJCTT Journal
Volume-4 Issue-5                           
Year of Publication : 2013
Authors :Ms. Priyanka, Ms.Harleen Kaur, Mr.Dileep Kumar Kushwaha


Ms. Priyanka, Ms.Harleen Kaur, Mr.Dileep Kumar Kushwaha"Reviewing Effectiveness of CAPTCHA "International Journal of Computer Trends and Technology (IJCTT),V4(5):1306-1311 May Issue 2013 .ISSN Published by Seventh Sense Research Group.

Abstract: - The massive use of the Internet and WWW by the government and commercial organizations for automation of work has resulted in extensive proliferation of online computing. To avoid online forms being filled by bots or malicious computers the form designers usually use a cryptic image known as CAPTHA (Completely Automated Public Turing test to Tell Computers and Humans Apart) [CAPTCHA] which is human readable and the form can be submitted only when the user has decrypted the captcha and filled in the text represented by that captcha. This type of visual and textual verification comes at a huge price to users who are blind, visually impaired or dyslexic. In many cases, these systems make it impossible for users with certain disabilities to create accounts, write comments, or make purchases on these sites, that is, CAPTCHAs fail to properly recognize users with disabilities as human. Also like every security system that has preceded it, this system can be defeated by those who benefit most from doing so. For example, spammers can pay a programmer to aggregate these images and feed them one by one to a human operator, who could easily verify hundreds of them each hour. The efficacy of visual verification systems is low, and their usefulness is nullified once they are commonly exploited.


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Keywords — CAPTCHA, Security, Online Form Processing,effectiness of captcha, captcha for disable human.