Analysis of various authentication schemes for passwords using images to enhance network security through online services

In this paper, we survey different authentication schemes for graphical passwords utilized in online services. Click-based graphical password scheme is used to garner click-points or pixel-points from users and to portend the hotspots. CAPTCHA scheme gives protection against spyware attacks. In the case of Face DCAPTCHA scheme, the users must recognize visually-distorted human faces from complex images in an accurate manner. A Password Guessing Resistant Protocol (PGRP) can limit large number of login attempts from unknown remote hosts to resist large-scale online password guessing attacks. An Image Recognition CAPTCHA (IRC) called Cortcha is designed to provide protection against machine learning attacks. In the Pass-Go scheme, the user has to select PassPoints on a grid to input the password. Creation of cryptographic primitives makes the graphical passwords invisible to attackers and hackers. A Hotspot or a PassPoint in an image can be generated as a Captcha as gRaphical Passwords (CaRP) image, which is our proposed work, for reducing security problems occurred by online password guessing attacks, relay attacks, dictionary attacks and shoulder-surfing attacks.