An automated system and method to authenticate one or more users based on capturing one or more images of a set of teeth, obtaining a selected image from the one or more captured images and extracting a portion of the selected image to obtain an extracted image. Each extracted image is converted into a grayscale image and stored in a database along with the username and the user keyword of the one or more users. A unique signature matrix and a pattern vector is generated by processing the grayscale image and stored in the database along with the username. One or more images comprising a set of teeth of at least one user is captured and a unique signature matrix obtained from the same is compared with a set of unique signature matrices previously stored in the database and at least one action is triggered based on the comparison.