Sergio Marti Hector Garcia-Molina Identity Crisis: Anonymity vs. Reputation in P2P Systems. 134-141 2003 conf/p2p/2003 Peer-to-Peer Computing http://csdl.computer.org/comp/proceedings/p2p/2003/2023/00/20230134abs.htm db/conf/p2p/p2p2003.html#MartiG03