A system and method for controlling access to multiple public networks and for controlling access to multiple private networks is provided. Authentication is used with unique public shared secrets and unique private shared secrets to control access to the networks. The invention includes a user device for communicating with at least a public network and/or a private network. The device may be capable of accessing multiple networks through one or more private networks with multiple access control servers. The user device must provide a correct response to each access control server, before access to the network may be granted. The device generates a one-time password, or response, to gain access to a controlled network server. The response generated by the device is matched to a response generated by an access control server that may have generated a challenge that prompted the response. If the two responses match, the device is authenticated and a user of the device is granted access to the network server.