Transparent Authentication across Heterogeneous Wireless Network Technologies: a Minimum-impact Architectural Framework

One of the more interesting and desirable features of the next generation mobile communication systems, usually referred to as systems beyond 3G, is represented by the inter-operation of different fixed and mobile networking technologies. Contrary to classic horizontal handover which is forwarding of an active connection from one cell to another of the same network, an inter-system handover implies switching from a serving cell of a given technology to another one, like UMTS to WLAN, providing very different security features such as access control, and cryptographic facilities. Each of the access network technologies and stakeholders have their own security requirements and mechanisms, making the integration of multiple access technologies more challenging. When looking at the problem scope of heterogeneous network security we see the opening of Pandora's Box. In this paper, we propose an architectural framework to provide transparent end-user authentication across heterogeneous wireless networks, built on existing 3G and WLAN security technologies and based upon the harmonization, without modifications to consolidated protocols, of multiple independent legacy authentication mechanisms.