Haifeng Yu Phillip B. Gibbons Michael Kaminsky Feng Xiao SybilLimit: A Near-Optimal Social Network Defense against Sybil Attacks. 3-17 2008 IEEE Symposium on Security and Privacy http://doi.ieeecomputersociety.org/10.1109/SP.2008.13 conf/sp/2008 db/conf/sp/sp2008.html#YuGKX08