@incollection{,
	
					
					
					C0D3EC22ECCE027BDDC41C930BF8D05C
				,
	author={{SilkyAzad} and {Kurukshetra University, Kurukshetra.}},
	journal={{Global Journal of Computer Science and Technology}},
	journal={{GJCST}}0975-41720975-435010.34257/gjcst,
	address={Cambridge, United States},
	publisher={Global Journals Organisation}1331517
}

@incollection{b0,
	
	
		,
	title={{CAPTCHA: using hard AI problems for security}}
		,
	author={{
			ManuelLuis Von An
		} and {
			NicholasJBlum
		} and {
			JohnHopper
		} and {
			Langford
		}}
		
		
		
	
	
		,
	booktitle={{Proceedings of the 22nd international conference on Theory and applications of cryptographic techniques (EUROCRYPT'03)}}
				the 22nd international conference on Theory and applications of cryptographic techniques (EUROCRYPT'03)Eli Biham; Berlin, Heidelberg
		
			,
	publisher={Springer-Overflag}
			,
	year={2003}
			
		
	

}

@incollection{b1,
	
	
		,
	title={{Re CAPTCHA: Human-Based Character Recognition via Web Security Measures}}
		,
	author={{
			BenLuis Von An
		} and {
			ColinMaurer
		} and {
			DavidMcmillan
		} and {
			ManuelAbraham
		} and {
			Blum
		}}
		
		
		
		
	
	
		,
	journal={{Science}}
		
			321
			5895
			
			,
	year={2008}
		
	

}

@incollection{b2,
	
	
		,
	title={{Re: CAPTCHAs: understanding CAPTCHA-solving services in an economic context}}
		,
	author={{
			MartiMotoyama
		} and {
			KrillLevchenko
		} and {
			ChrisKanich
		} and {
			DamonMccoy
		} and {
			GeoffreyMVolker
		} and {
			StefanSavage
		}}
		
		
		
		
		
	
	
		,
	booktitle={{Proceedings of the 19th USENIX conference on Security (USENIX Security'10). USENIX Association}}
				the 19th USENIX conference on Security (USENIX Security'10). USENIX AssociationBerkeley, CA, USA
		
			,
	year={2010}
			
		
	

}

@incollection{b3,
	
	
		,
	title={{How Good Are Humans at Solving CAPTCHAs? A Large Scale Evaluation}}
		,
	author={{
			ElieBursztein
		} and {
			StevenBet Hard
		} and {
			CelineFabry
		} and {
			JohnCMitchell
		} and {
			DanJurafsky
		}}
		
		
		
		
	
	
		,
	booktitle={{Proceedings of the 2010 IEEE Symposium on Security and Privacy (SP '10)}}
				the 2010 IEEE Symposium on Security and Privacy (SP '10)Washington, DC, USA
		
			,
	publisher={IEEE Computer Society}
			,
	year={2010}
			
		
	

}

@incollection{b4,
	
	
		,
	title={{Text-based CAPTCHA strengths and weaknesses}}
		,
	author={{
			ElieBursztein
		} and {
			MathieuMartin
		} and {
			JohnMitchell
		}}
		
		
	
	
		,
	booktitle={{Proceedings of the 18th ACM conference on Computer and communications security (CCS '11)}}
				the 18th ACM conference on Computer and communications security (CCS '11)New York, NY, USA
		
			,
	publisher={ACM}
			,
	year={2011}
		
	

}

@incollection{b5,
	
	
		,
	title={{The robustness of a new CAPTCHA}}
		,
	author={{
			Ahmad Salah ElAhmad
		} and {
			JeffYan
		} and {
			LindsayMarshall
		}}
		
		
	
	
		,
	booktitle={{Proceedings of the Third European Workshop on System Security (EUROSEC '10)}}
				the Third European Workshop on System Security (EUROSEC '10)New York, NY, USA
		
			,
	publisher={ACM}
			,
	year={2010}
		
	

}

@incollection{b6,
	
	
		,
	title={{Attacks and Design of Image Recognition CAPTCHAs}}
		,
	author={{
			BBin
		} and {
			Zhu
		}}
		
	
	
		,
	journal={{ACM, Microsoft Research}}
		
			,
	year={OCT 2010}
		
		
			Temple University, Computer and Information Science
		
	

}

@incollection{b7,
	
	
		,
	title={{Re: CAPTCHAs: understanding CAPT-CHA solving services in an economic context}}
		,
	author={{
			MartiMotoyama
		}}
	
	
		,
	booktitle={{Proceedings of the 19th USENIX conference on Security 28-28. v}}
				the 19th USENIX conference on Security 28-28. v
		
			,
	year={2010}
		
	

}