The ubiquity of cell phones, and increasingly smartphones, means that many forms of identity authentication can be moved from costly and easy-to-lose physical ID cards to mobile access platforms. QR codes, NFC, and other wireless-based technologies are already starting to be used for security authentication and single-use sign-on for website access.
Work identity badges, hospital access badges, and government and school IDs are examples of physical-world ID cards that can be moved to smartphone ID cards. Likewise many services linking identity authentication to resource-access and mobile payment can be automated, for example, event tickets, work conference room reservation and access, medical equipment and pharmaceutical inventory access, and rental car and hotel check-in and resource access. Digital ID cards can incorporate multi-factor authentication: for example, the visual look, a custom sound or image elicited upon being tapped, or information returned from an external server as the QR code is read.