Anonymous communication in sensor networks is an important security tool. A major sensornet security issue is to anonymize sources and sinks in sensor networks despite the inability to hide wireless transmissions. However, none of the existing anonymous communication schemes provide complete protection against attacks posed by different types of adversaries. In this paper, we propose a novel and scalable anonymous communication scheme Randomized Message Forwarding with Equalized Incoming/Outgoing Traffic Rate (RMFETR) which resists all known eavesdrop attacks. A further modification of this scheme Destination First Randomized Message Forwarding with Equalized Incoming/Outgoing Traffic Rate (DFRMFETR) improves message delivery time significantly. We present security analysis and performance analysis of these two schemes. While both RMFETR and DFRMFETR have the same security benefits against eavesdrop attacks as the randomized Buses protocol, they are more flexible and easy to implement. The expected message delivery time under RMFETR is same as that under the randomized Buses, while DFRMFETR induces a smaller delivery time.
