An anti-tracking source-location privacy protection protocol in WSNs based on path extension

In the application field using sensor networks to monitor valuable asset, source-location anonymity is a serious concern. As a series of event packets are reported to the base station, adversaries eavesdropping on the network can backtrack to the source through traffic analysis and the RF localization techniques. This leakage of contextual information will expose sensitive or precious objects and bring down the effectiveness of sensor networks. Existing techniques such as phantom routing or source simulation are proposed to discourage the adversaries, both of which trade energy for security. In this paper, we propose a new scheme, called path extension method (PEM), providing strong protection for source-location privacy. It performs quite well even though an object occurs near the base station, while other methods cannot protect the source well in this case. In PEM, fake sources are generated dynamically after the source sends event messages to the base station, which makes it much more flexible. Fake sources form several fake paths in the network and an adversary will be induced farther away from the source if it is entrapped by any of them. The theoretical and simulation results show that PEM is efficient in protecting source-location privacy with minimal message delivery delay and acceptable overhead.