A method of authenticating a first computing device in communication over a network to a second computing device is disclosed. The first computing device is authenticated to the second computing device using a first authentication mechanism. The first authentication mechanism is based on Extensible Authentication Protocol (EAP) or IEEE 802.1x authentication. Short-term re-authentication data is generated and issued to the first computing device. Later, a request from the first computing device to re-authenticate to the second computing device is received. The first computing device is re-authenticated to the second computing device using a challenge-response mechanism in which the first computing device authenticates itself by presenting the short-term authentication credential to the second computing device. Accordingly, re-authentication proceeds more quickly and with fewer message exchanges.