G2G: Privacy-preserving group matching for proximity-based mobile social networks

The explosive development of mobile devices and position systems makes it possible and meaningful for Proximity-based Mobile Social Networks (PMSNs), in which social group networking is among the most prominent features. In order to choose a suitable friend group, a group needs to find another group in vicinity and computes the matching degree based on their attributes. Then, they decide whether to make new social interactions through WiFi/Bluetooth interfaces embedded in their mobile devices according to the matching information. However, since group attributes usually contain some sensitive information, users may have increasing privacy concerns and do not want to reveal them to strangers. In this paper, we propose G2G, a novel privacy-preserving group matching mechanism, which can support group matching with preserving the privacy of all group members by applying permutation function. Considering a few potential attacks, we design an enhanced version G2G+, which can further improve group privacy. By detailed analysis and evaluation, we demonstrate that the proposed schemes have a desirable performance on security, efficiency and communication traffic.