The invention provides a system and method for signing a user workstation onto an access restricted network utilizing a mobile communication device. The method includes receiving a sign-on request from a mobile communication device of a user of the network, looking up a user certificate included in the sign-on request in an enrollment database and retrieving identifiers relating to the user, the workstation and network from the database, and transmitting a sign-on command to an authentication driver operating on the workstation, in response to which the authentication driver negotiates a sign-on operation of the workstation onto the network.