Privacy-Preserving Communication Algorithms and Network Protocols

Abstract

Communication anonymity is becoming an increasingly important or even indispensable security requirement for critical information infrastructure protection and mission critical communications. Existing research in anonymous communications can largely be divided into two categories: mix-based systems and secure multiparty computation-based systems, originating from mixnet and DC-net respectively. However, all mix-based solutions require a trusted third party and cannot provide provable anonymity. While the secure multiparty computation-based approach suffers from transmission collusion problem that no practical solution exists to solve this problem. In this paper, we first propose a novel unconditionally secure source anonymous message (SAM) scheme that can be applied to any messages without relying on any trusted third parties. While ensuring message sender anonymity, the proposal scheme can also provide message content authenticity. We also propose a novel communication protocol that can hide both the senders and the recipients from each other and the network addresses of their end-to-end source and destination. The proposed protocols can be applied to both overlay networks as well as mobile ad hoc networks (MANETs). It can also be used for critical infrastructure protection and secure file sharing. The security analysis demonstrates that the proposed protocol is secure against various attacks. Our analysis also shows it is efficient and practical.