Abstract
The fast increase of mobile Internet use motivates the need for WiFi sharing solutions, where a mobile user connects to the Internet via a nearby foreign network while its home network is far away. This situation creates security challenges which are only partially solved by existing solutions like VPNs. Such solutions neglect the security of the visited network, and private users or organizations are thus reluctant to share their connection. In this paper, we present and implement SWISH, an efficient, full scale solution to this problem. SWISH is based on establishing a tunnel from the visited network to the user’s home network. All the data from the mobile is then forwarded through this tunnel. Internet access is therefore provided without endangering the visited network. We also propose protocol extensions that allow the visited network to charge for the data it forwards, and to protect the privacy of the mobile user while preventing abuse. SWISH was successfully deployed on university networks, demonstrating that it can be conveniently implemented in existing networks with a minimal impact on performance.