Infineon ID Key S USB - SLC38DU Infineon ID Key S USB SLC38DU combines the security, performance, and reliability of the SLC38 security crypto controller with a universal serial bus (USB) controller in a unique single-package-solution. It provides unparalleled flexibility and security, and simplifies also complex application deployments, making it an ideal choice for USB-based as well USB-/NFC-based tokens, dongles, FIDO security keys, and any type of hardware authenticators.