Image Captcha Based Authentication Using
A. Angel Freeda, M. Sindhuja, K. Sujitha · 2013
Anti-phishing mechanisms in the websites currently focus on helping users to verify whether a web site is genuine or not. Phishing on the web pages is an attempt by an individual or a group to threats/hackers trying to retrieve an individual’s personal confidential information such as passwords, usernames/confidential info, credit card information etc. In this project, we are proposing a new approach named as “Image Captcha Based Authentication Using Visual Cryptography to solve the problem of phishing. Textual keyword validation along with visual cryptography is a major advantage of this project. To increase more security “Blowfish Algorithm” can be used to divide the original image captcha into many blocks and rearrangement can be done. Then “Splitting and Rotating Algorithm” can be used to rotate the rearranged blocks. The use of visual cryptography technique((2,2) VCS scheme) is explored to preserve the privacy of image captcha by degenerating the original image captcha into two different image shares by manipulating the black and white pixel value of the image captcha. Part of the image share will be stored in the servers such that the original image captcha can be revealed only when both (client,server) of the shares are simultaneously available. The individual share images do not reveal the identity of the original image captcha. Once the original image captcha is revealed after merging different shares, which can be used as the password. Dynamically generating the Captcha image by the system is one of the major advantage of the system.