Abstract: A new authentication protocol based on 3G-WLAN interworking networks is proposed. It verifies the identity of the WLAN access network to prevent the malicious AP from the re-direction attack, and improves the efficiency of the reauthentication process by using localized authentication mechanisms for 3G mobile subscribers and offline accounting methods based on the fast signature. Simulation results show that the average message transmission delay of the proposed protocol is shortened about 45％ of EAP-AKA, and the proposed protocol can provide smooth roam and handover for 3G mobile subscribers in WLAN.

Key words: UMTS, wireless local area network, session key, EAP-AKA