The Xerox Unified Client can provide a Convenience Authentication (CA) service for Xerox MFDs. This is implemented as a web service hosted by the EWS. It allows for card reader and touch screen authentication. The credentials obtained are available to the Xerox Unified Client and other applications running on the device. On MFDs that support the Xerox Job Limits API, functional access control can also be enforced. This is where a user can be restricted from using features or functions of the MFD.