Abstract: A secure message facility transfers authentication data between various applications, operating systems, and authentication devices and software in the form of messages. These messages comprise a data structure with a standard header with fields that describe the class, length, and type of message, and routing information. This header information is used to route the message to the appropriate handler. The messages are transferred between applications via the messaging facility DLL and the messaging facility Service. The messaging facility DLL is intended to be loaded by an application. The messaging facility DLL forms the messages, directs them to the appropriate messaging facility service (local or remote) and interprets the responses. The messages sent between the messaging facility DLL and messaging facility Service are extremely flexible and can be used to send any type of data or content of messages.