Building Secure Tunnel from PPP Wireless Network

The rapid development of mobile businesses raises the need for exchanging information between mobile computing devices via Internet. If a secure connection is necessary then a virtual private network (VPN) is essential. Currently, VPN protocols set up secure connections between two nodes with fixed IP addresses. However, if several people work in a moving vehicle with their mobiles or computers, the secure connection will be lost due to the IP change and a new connection has to be built from scratch. The current solution to this problem is to run tunnels over Mobile IP (MIP). However, that is inefficient due to double tunneling. In this paper, the authors add a novel form of mobility support to secure L2TP/IPsec tunnels which will be shared by everyone in the vehicle using a Point-to-Point Protocol (PPP) wireless network. The mobility support properly handles the IP change (users may even change to a different kind of network such as from Universal Mobile Telecommunications System (UMTS) to Worldwide Interoperability for Microwave Access (WiMAX) without using an MIP, and without incurring tunnel-re-establishment at handoff. The novel solution achieves better security than current mobility solutions for VPN, and supports fast handoff in IPv4 networks.