Securing roaming and vertical handover in fourth generation networks

Wireless 4G networks are the result of the interconnection of different wireless access networks and a core network. The heterogeneity of 4G networks require the implementation of a vertical authentication scheme that reduces the handover delay while preserving the security context of the ongoing communication. This paper proposes a complete vertical authentication scheme integrating the GSM, UMTS, WiFi and WiMAX technologies that enables a vertical handover without requiring a prior subscription to the visited network. We also prove the immunity of our scheme against some heterogeneous attacks.