Patent ID: 8407762

Claim:
A system for authenticating a user, said system performing three level authentication on the basis of selection of at least one predefined image from a plurality of images including decoy images and further selection of at least one predefined tile in the tiled version of the selected images to generate a transaction key, said system comprising: an authentication server comprising an authentication repository storing user authentication data including at least one password image serving as correct response for a first level authentication challenge, tiled version of password image and at least one password tile serving as correct response for second level authentication challenge; first authentication challenge generation means adapted to generate a first level authentication challenge for the user by formulating a group of images including a plurality of decoy images and said at least one password image to be displayed on user's computing node; transmitting means adapted to transmit said first level authentication challenge, at least one password image, tiled version of password image and at least one password tile on to a user's computing node; user's computing node receiving said first level authentication challenge, at least one password image, tiled version of password image and at least one password tile, said user's computing node including displaying means adapted to display the group of images contained in said received first level authentication challenge; first selection means adapted to allow the user to select at least one image from the plurality of images displayed on the computing node; second authentication challenge generation means adapted to generate second level authentication challenge by displaying the tiled version of the password image containing a plurality of tiles in case the selected image is the password image; frame locomotion means adapted to provide an outlining frame randomly moving across each of the plurality of tiles after a finite delay; second selection means adapted to allow the user to select at least one tile currently outlined by said outlining frame from the plurality of tiles displayed on the computing node; and authenticating message generation means adapted to generate authenticating message in case the selected tile is the password tile; a transaction key generating server cooperating with said user's computing node and configured to transmit a transaction key to said user's computer node on receiving an authenticating message from said authentication message generation means, said transaction key to be used for final account login and grant of transaction rights.