Providing source privacy in mobile ad hoc networks

Communication privacy is becoming an essential security requirement for mission critical communications and communication infrastructure protection. This is especially true for mobile ad hoc networks (MANETs) due to mobility of the communication nodes and the nature of wireless communications. Existing research in privacy-preserving communications can largely be divided into two categories: cryptosystem-based techniques and broadcasting-based techniques. The cryptosystem-based techniques include mix-based systems and secure multiparty computation-based systems, originating from mixnet and DC-net respectively. All mix-based approaches require a trusted third party to provide the mix and are not quite feasible in MANET. However, DC-net based approaches suffer from transmission collision problem that cannot be easily resolved practically. Broadcasting based schemes provide communication privacy by mixing the real messages with dummy packets so that it is infeasible for the adversaries to identify the real packets and track the message source. However, the transmission of dummy messages not only increases the energy consumption significantly, but also increases the network collisions and decreases the packet delivery ratio. In this paper, we first propose a novel unconditionally secure source anonymous message authentication scheme (SAMAS) that enables messages to be released without relying on any trusted third parties. While providing source privacy, the proposed scheme can also provide message content authenticity. We then propose a novel communication protocol for MANET that can ensure communication privacy of both communication parties and their end-to-end routing. The proposed protocol can be used for critical infrastructure protection and secure file sharing. The security analysis demonstrates that the proposed protocol is secure against various attacks. The theoretical analysis and simulation show that the proposed scheme is efficient and can ensure high message- delivery ratio.