CACKey provides a standard interface (PKCS #11) for smartcards connected to a PC/SC compliant reader. It performs a similar function to "CoolKey", but only supports Government Smartcards. It supports all Government Smartcards that implement the Government Smartcard Interoperability Specification (GSC-IS) v2.1 or newer as well as PIV cards that comply with NIST SP 800-73-3.