Accessing Smart City Services in Untrustworthy Environments via Decentralized Privacy-Preserving Overlay Networks

For managing sensor-based data and services in advanced smart city environments, citizen participation in open private and public network environments plays an increasingly important role. Various approaches allow citizens to share, e.g., local sensors, urban data, and services to increase environmental awareness. Although privacy and (data and service) sovereignty is essential in citizen participation, most of these approaches rely on centralized trusted third parties or are unsuitable to be operated in untrustworthy (e.g., public) network environments. This paper presents drasyl, a fully decentralized transport overlay network that also accommodates related trust and reliability issues. Consequently, drasyl allows citizens to access services and applications in public untrustworthy IP-based networks without nedding a central trusted third-party service. drasyl provides means to strengthen citizens' privacy by end-to-end encrypted communication and utilizes methods to hide communication and service access between citizens from unauthorized third parties. Finally, the paper demonstrates how drasyl can be used as a basis for a peer-to-peer middleware that helps develop distributed applications.