Private Badges for Geosocial Networks
GeoSocial Networks (GSNs) extend classic online social networks with the concept of location. Users can report their presence at venues through \"Check-ins\" and, when certain check-in sequences are satisfied, users acquire special status in the form of \"Badges\". Furthermore, they address the apparent tension between privacy and correctness, where users are unable to prove having satisfied badge conditions without revealing the corresponding time and location of their check-in sequences. To this end, they propose several privacy preserving protocols that enable users to prove having satisfied the conditions of several badge types.