Asynchronous reputation systems in device-to-device ecosystems

Advances in device-to-device (D2D) ecosystems have brought on mobile applications that utilise nearby mobile devices in order to improve users' quality of experience (QoE). The interactions between the mobile devices have to be transparent to the end users and can be of many services - opportunistic networking, traffic offloading, computation offloading, cooperative streaming and P2P based k-anonymity location privacy service, to name a few. Whenever mobile users are willing to “ask for help” from their neighbours, they need to make non trivial decisions in order to maximise their utility. Current motivation approaches for mobile users that participate in such environments are of two types: (i) credit-based and (ii) reputation-based. These approaches rely either on centralised authorities or require prohibitively many messages or require tamper resistant security modules. In this paper we propose a trust-based approach that does not require synchronisation between the mobile users. Moreover, we present the three-way tradeoff between, consistency, message exchange and awareness and we conclude that our approach can provide first-rate data to neighbour selection mechanisms for D2D ecosystems with much less overhead.