Abstract
The proliferation of broadband Internet connections has lead to an almost pervasive coverage of densely populated areas with private wireless access points. To leverage this coverage, sharing of access points as Internet uplinks among users has first become popular in communities of individuals and has recently been adopted as a business model by several companies. However, existing implementations and proposals suffer from the security risks of directly providing Internet access to strangers. In this paper, we present the P2P Wi-Fi Internet Sharing Architecture PISA, which eliminates these risks by introducing secure tunneling, cryptographic identities, and certificates as primary security concepts. Thus, PISA offers nomadic users the same security that they expect from a wired Internet connection at home. Based on its three fundamental mechanisms, PISA achieves a flexibility which opens significant advantages over existing systems. They include user mobility, anonymity, service levels with different performance and availability characteristics, and different revenue models for operators. With this combination of key features, PISA forms an essential basis for global, seamless, and secure Wi-Fi sharing for large communities.
