1. One or more non-transitory computer readable media having computer readable instructions stored thereon for authenticating a user of a computing device, the computing device having a memory storing a base image and an overlay image, the base image having a selected base image reference point, and the overlay image having a selected overlay image reference point, which when executed by a processor direct the computing device to: generate a modified base image; generate a modified overlay image; display, on a display area of a touchscreen, the modified base image overlaid by the modified overlay image; receive an input, the input starting outside the display area of the touchscreen and at least an initial portion of the input being received from a touch-sensitive border around the display area; move the one of the modified base image and the modified overlay image only in response to receiving the input; and in response to alignment of the base image reference point on the modified base image with the overlay image reference point on the modified overlay image at a point on the display area after the move, indicate positive authentication.