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CAPTCHA: A Security Review

International Journal of Computer Applications
Foundation of Computer Science (FCS), NY, USA
Year of Publication: 2017
Sudarshan Soni, Padma Bonde

Sudarshan Soni and Padma Bonde. CAPTCHA: A Security Review. International Journal of Computer Applications 168(4):44-47, June 2017. BibTeX

	author = {Sudarshan Soni and Padma Bonde},
	title = {CAPTCHA: A Security Review},
	journal = {International Journal of Computer Applications},
	issue_date = {June 2017},
	volume = {168},
	number = {4},
	month = {Jun},
	year = {2017},
	issn = {0975-8887},
	pages = {44-47},
	numpages = {4},
	url = {},
	doi = {10.5120/ijca2017914377},
	publisher = {Foundation of Computer Science (FCS), NY, USA},
	address = {New York, USA}


Completely Automated Public Turing test to tell Computers and Human Apart(CAPTCHA) is an automated test that humans can pass, but current computer programs could not pass. The main purpose of CAPTCHA is to block automated scripts that are posted spam content everywhere they can. In this paper, various types of CAPTCHA techniques has been discussed. There is a constant require to enhance current CAPTCHAs and to develop new CAPTCHAs in order to provide security against newly generated programs which can create thousands of e-mail accounts used for stuff online polls with ballots, malicious purposes, and develop worms and viruses contained in emails.


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CAPTCHA, Graphical Password Authentication, Hard AI Problem, Attack.