Downloadable digital image files of avatars authenticated by non-fungible tokens (NFTs); Downloadable computer programs for issuing digital certificates authenticated by non-fungible tokens (NFTs); Downloadable digital image files of works of art authenticated by non-fungible tokens (NFTs); Digital collectibles in the nature of downloadable image files of toys authenticated by non-fungible tokens (NFTs); Downloadable digital image files of fantasy story elements authenticated by non-fungible ...