Patent ID: 8407474

Claim:
A pre-authentication method for authenticating a mobile node (MN) when the mobile node (MN) enters a visited network other than a home network, comprising: obtaining by the MN, identity information of the visited network; generating by the MN, a pre-auth-key according to the identity information of the visited network; and performing by the MN and a visited authentication, authorization and accounting (VAAA) server, mutual authentication according to the pre-auth-key, wherein before the MN entering the visited network, judging by a network access device on a network where the MN is located, whether a potential visited network exists around the network; if the potential visited network exists around the network, sending identity information of the potential visited network to the HAAA server, wherein after receiving the identity information of the potential visited network by the HAAA server, generating a pre-auth-root-key according to an MN ID, the identity information of the HAAA server and an AAA key, wherein the AAA key refers to a key file generated when the HAAA server performs Extensible Authentication Protocol (EAP) authentication on the MN; generating a pre-auth-key according to the identity information of the potential visited network and the pre-auth-root-key, sending the pre-auth-key to the VAAA server; generating by the MN, a pre-auth-root-key according to the MN ID, the identity information of the HAAA server and the AAA key; before entering the visited network; obtaining the identity information of the visited network; and generating a pre-auth-key according to the identity information of the visited network and the pre-auth-root-key.