Efficient oblivious augmented maps: Location-based services with a payment broker

Abstract

Secure processing of location data in location-based services (LBS) can be implemented with cryptographic protocols. We propose a protocol based on oblivious transfer and homomorphic encryption. Its properties are the avoidance of personal information on the services side, and a fair revenue distribution scheme. We discuss this in contrast to other LBS solutions that seek to anonymize information as well as possible towards the services. For this purpose, we introduce a proxy party. The proxy interacts with multiple services and collects money from subscribing users. Later on, the proxy distributes the collected payment to the services based on the number of subscriptions to each service. Neither the proxy nor the services learn the exact relation between users and the services they are subscribed to.