Mingqiang Xue Barbara Carminati Elena Ferrari P3D - Privacy-Preserving Path Discovery in Decentralized Online Social Networks. 48-57 2011 COMPSAC http://doi.ieeecomputersociety.org/10.1109/COMPSAC.2011.15 conf/compsac/2011 db/conf/compsac/compsac2011.html#XueCF11