Distributed Coverage of Ego networks in F2F Online Social Networks

Although most online social networks rely on acentralized infrastructure, several proposals of Distributed OnlineSocial Networks (DOSNs) have been recently presented. Sincein DOSNs user profiles are stored on the peers of the usersbelonging to the network, one of the main challenges comes fromguaranteeing the profile availability when the owner of the data isnot online. In this paper, we propose a DOSN based on a friend-to-friend P2P overlay where the user's data is stored only onfriend peers. Our approach is based on the ego-network concept,which models the social network from the local point of viewof a single user. We propose a distributed algorithm which isbased on the notion of coverage of the ego-network and assuresthat users store their data only on the peers of their friends, andthat each online user can retrieve the private data of its offlinefriends through a common online friend. We formalize this as aNeighbour Dominating Set problem. A set of experimental resultsconducted on real Facebook dataset show the effectiveness of our approach.