A Hierarchical Anonymous Communication Protocol for Sensor Networks

Ensuring anonymity in sensor networks is a major security goal. Using traffic analysis, the attacker can compromise the network functionality by correlating data flow patterns to event locations/active areas. In this paper we present a novel hierarchical anonymous communication protocol that hides the location of nodes and obscure the correlation between event zones and data flow from snooping adversaries. We quantify the anonymity strength of our protocol by introducing a new anonymity metric: Degree of Exposure Index. Our protocol is designed to offer flexible tradeoffs between degree of anonymity and communicationdelay overhead.