Basic types Basic types This element is only valid for two-pass DSKPP. Authentication data contains a MAC. Extension types DSKPP PDUs Message used to trigger the device to initiate a DSKPP protocol run. KeyProvClientHello PDU Message sent from DSKPP client to DSKPP server to initiate a DSKPP session. KeyProvServerHello PDU Response message sent from DSKPP server to DSKPP client in four-pass DSKPP. KeyProvClientNonce PDU Response message sent from DSKPP client to DSKPP server in a four-pass DSKPP session. KeyProvServerFinished PDU Final message sent from DSKPP server to DSKPP client in a DSKPP session. A MAC value serves for key confirmation, and optional AuthenticationData serves for server authentication.