IJIRCSTJournal International Journal of Innovative Research in Computer Science and Technology I S Volume 3 Issue 2 computer science & engineering English March - April 2015 N N Y 2019 11 30 Computer Sciences A New Security Primitive Based on Hard AI Problems and Efficient User Authentication using Captcha and Graphical Passwords English Y 121 124 Bhagyashri A. Banarase English Y Prof. Meghali A. kalyankar English N In this paper,I present a new security primitive based on hard AI (Artificial Intelligence) problems, namely, a novel family of graphical password systems built on top of Captcha technology, which we call Captcha as graphical passwords (CaRP) [1].CaRP is a combination of both a captcha and a graphical password scheme [3].With the hybrid use of captcha and graphical password one can addresses a number of security problems such as relay attacks, online guessing attacks and also shoulder surfing attacks[4].a new security primitive based on hard AI problems, namely, a novel family of graphical password systems integrating captcha technology, which is called CaRp (Captcha as gRaphical Passwords).CaRp is click-based graphical passwords, where a sequence of clicks on an image is used to derive a password. Unlike other click-based graphical passwords, images used in CaRpare captcha challenges [7].The CaRP scheme is enhanced with more attack handling mechanisms that improves the level of security in online application system and also provides better authentication [6]. English AI, captaha, CaRP, Graphical password, User Authentication. https://ijircst.org/abstract.php?article_id=184