Survey on Anonymity in Unstructured Peer-to-Peer Systems

Although anonymizing Peer-to-Peer (P2P) networks oftenmeans extra cost in terms of transfer efficiency, many systems try tomask the identities of their users for privacy consideration. Bycomparison and analysis of existing approaches, we investigate theproperties of unstructured P2P anonymity, and summarize current attackmodels on these designs. Most of these approaches are path-based, whichrequire peers to pre-construct anonymous paths before transmission,thus suffering significant overhead and poor reliability. We alsodiscuss the open problems in this field and propose several futureresearch directions.