Network coding for anonymous broadcast

Abstract

This thesis explores the use of network coding for anonymous broadcast. Network coding, the technique of transmitting or storing mixtures of messages rather than individual messages, can provide anonymity with its mixing nature, efficiently disseminate content in multicast and broadcast networks, and resiliently deliver messages despite packet erasure and constrained network resources. While broadcast mediums guarantee receiver anonymity, they are thought to be difficult to emulate efficiently over unicast networks. This thesis introduces NCGAB, a decentralized peer-to-peer overlay network based on network coded gossip that provides a resilient, anonymous broadcast medium. Unlike most anonymous communication systems, NCGAB requires no cryptosystem, no infrastructure of trust, and no special nodes to operate. This thesis also introduces Melting Pad, an algebraic coding scheme with properties of information theoretic security and efficient decodability, designed to protect messages for wide dissemination and for hosting with diminished liability.