1. A non-transitory computer-readable medium containing instructions executable by at least one processor for, the computer-readable medium comprising: one or more instructions for providing sub-images; one or more instructions for providing sub-image regions; one or more instructions for receiving selection of a plurality of sub-images into a plurality of sub-image regions; one or more instructions for constructing a first image using the selected sub-images, the first image being part of a unified image; one or more instructions for determining whether a sub-image region is occupied; one or more instructions for comparing the selected plurality of sub-images with previously selected sub-images in response to determining the sub-image region is occupied; and one or more instructions for providing access to at least one of a device, a service, or a function when the selected plurality of sub-images match the previously selected sub-images.