A Machine Authentication PAC (Protected Access Credential) serves as
machine credentials to obtain network access without requiring server
storage and management of the additional set of credentials. The first
time authentication is performed, user authentication is executed. After
the supplicant and server have mutually authenticated each other and
satisfied other validations, the supplicant requests a Machine
Authentication PAC from the server. The Server randomly generates a
cryptographic key (Device Key) and sends it to the supplicant along with
an encrypted ticket, comprising the Device Key and other information and
encrypted with a key only known to the Server. The supplicant caches the
Machine Authentication PAC in its non-volatile memory for future use.
When the machine needs to access certain network services before a user
is available, the supplicant uses the Machine Authentication PAC to gain
authorization for the machine to limited access on the network, without
requiring user input.