University of Washington School of Public Health & Community Medicine
Existing anonymous communication systems like tor do not scale well as they require all users to maintain up-to-date information about all available tor relays in the system. Current proposals for scaling anonymous communication advocate a Peer-To-Peer (P2P) approach. While the P2P paradigm scales to millions of nodes, it provides new opportunities to compromise anonymity. In this paper, the authors step away from the P2P paradigm and advocate a client-server approach to scalable anonymity. They propose PIR-Tor, architecture for the tor network in which users obtain information about only a few onion routers using private information retrieval techniques.