A system for efficiently reauthenticating a client of a network. In a specific embodiment, the system includes an authentication server and a Security GateWay (SGW) in communication with the client. The SGW includes reauthentication information associated with the client. In a more specific embodiment, the authentication server includes an Authentication, Authorization, and Accounting (AAA) server. The SGW further includes one or more routines for employing the reauthentication information to reauthenticate the client. The AAA server performs initial authentication of the client to enable client access to the network, which yields the reauthentication information. The reauthentication information includes one or more keys and/or counters, such as an authorization key, an encryption key, and a master key, which is/are predetermined by the AAA server.