A system and method for consistent authentication and security mechanism to enable a client device to easily roam from one network to another without requiring the client to manually change network configurations is disclosed. In one embodiment, a client device listens for a "beacon frame" broadcast from a Wi-Fi access point. The beacon frame identifies the basic service set identifier (BSSID) of the access point. A tamper-resistant token, or client key, installed at the client device stores a set of authentication parameters, e.g., cryptographic keys, for each Wi-Fi network the client is permitted to access. Each set of authentication parameters is associated with a particular BSSID. Using the BSSID received from the access point, the client device identifies and implements the appropriate set of authentication parameters necessary to authenticate the client device according to an authentication process generally accepted by all the Wi-Fi networks potentially servicing the client.