Mutual anonymity protocols for hybrid peer-to-peer systems 

Li Xiao, Zhichen Xu, and Xiaodong Zhang 
 
Proceedings of the 23rd International Conference on Distributed Computing
Systems, (ICDCS'2003), Providence, Rhode Island, May 19-22, 2003.

Abstract


Peer-to-Peer (P2P) offers an attractive alternative to the traditional
client/server model, and can better utilize increasingly decentralized
network resources. P2P, however, also faces several technical challenges,
including how to effectively implement distributed controls and how to
enforce trust and anonymity. In this paper, we propose several protocols
to enforce mutual communication anonymity in a P2P information-sharing
environment. In contrast to earlier work that either assumes a
client/server model or a P2P environment without relying any trusted
servers, our work focuses on P2P systems where some centralized support,
such as a proxy server, is available. Our techniques anonymize the link
between a provider peer (sender) and a consumer peer (receiver) such that
neither the sender, nor the receiver, nor any other peer can guess the
identities of the two communicating parties. With a limited support of
trusted servers, we show that our proposed anonymity proposals are highly
cost-efficient and reliable.  We have also proposed a mutual anonymity
protocol solely relying on self-organizations among peers. Compared with
existing protocols for the same purpose, the communication cost in our
protocol is significantly reduced.  We have evaluated our techniques
in a browser-sharing environment. We show that the average increment in
response time caused by our protocols is trivial, and highly justifiable
to be used in a P2P system.