Toward an analytical approach to anonymous wireless networking

Communications in a wireless network are susceptible to unauthorized traffic analysis by eavesdroppers. Although cryptography can protect the contents of communication, the transmission times of packets alone can reveal significant networking information such as source- destination pairs and routes of traffic flow. This article focuses on analytical approaches to anonymous networking for the prevention of information retrieval through packet timing analysis. In particular, an analytical measure for route anonymity is proposed using information theoretic equivocation. Based on the metric, provably anonymous countermeasures are described for wireless ad hoc and sensor networks, where traffic is subjected to strict constraints on medium access and latency. A key objective is to bridge a long standing gap between the information theoretic approach to secrecy in communication, and a more pragmatic approach of Chaum mixing used in anonymous systems on the Internet. The efficacy of the proposed approach is demonstrated using an orthogonal transmitter directed signaling network.