enClosure: Group Communication via Encounter Closures (poster)

ABSTRACTNew applications enabled by personal smart devices and the Internet-of-Things (IoT) require communication in the context of an encounter (a period of spatial co-location). However, existing encounter-based communication (EbC) systems are limited to communication among participants that share a direct encounter. This work is inspired by two insights: (1) encounters also enable group communication among devices connected by paths in the encounter graph that is contextual, spontaneous, secure, and privacy-preserving; and (2) addressing communication partners using encounter closures subject to causal, spatial, and temporal constraints enables powerful new forms of group communication. We present the design of enClosure, a service providing group communication based on encounter closures for mobile and IoT applications, and a prototype implementation for Android and the Microsoft Embedded Social Cloud platform. Using real-world traces, we show that enClosure provides a privacy-preserving, secure platform for a wide range of group communication applications ranging from connecting attendees of a large event to disseminating health risk warnings and tracing missing persons.