A Security Protocol for Mutual Authentication and Mobile VPN Deployment in B3G Networks

This paper proposes a security protocol that provides mutual authentication between a user and a WLAN that the first tries to connect to, and deploys a mobile Virtual Private Network (VPN) that protects the user´s data conveyed over the wireless network. For the user authentication as well as for the initialization of the VPN and the related key agreement, the EAP-SIM encapsulated within the Internet Key Exchange version 2 (IKEv2) is proposed. The deployed VPN, which is based on IPsec, ensures confidentiality, source authentication and integrity of the data exchanged over the WLAN. At the same time, the user has been subscribed to the 3G-network for charging and billing purposes using the legacy EAP-SIM authentication protocol. The established VPN can seamlessly operate and continuously provide security services as the mobile user moves and roams, materializing the notion of mobile VPN. The proposed security protocol eliminates the required enhancements to the current network infrastructure and operates transparently to the existing network functionality.