Secure Data Aggregation in Wireless Sensor Networks

In a large sensor network, in-network data aggregation significantly reduces the amount of communication and energy consumption. Recently, the research community has proposed a robust aggregation framework called synopsis diffusion which combines multipath routing schemes with duplicate-insensitive algorithms to accurately compute aggregates (e.g., predicate Count, Sum) in spite of message losses resulting from node and transmission failures. However, this aggregation framework does not address the problem of false subaggregate values contributed by compromised nodes resulting in large errors in the aggregate computed at the base station, which is the root node in the aggregation hierarchy. This is an important problem since sensor networks are highly vulnerable to node compromises due to the unattended nature of sensor nodes and the lack of tamper-resistant hardware. In this paper, we make the synopsis diffusion approach secure against attacks in which compromised nodes contribute false subaggregate values. In particular, we present a novel lightweight verification algorithm by which the base station can determine if the computed aggregate (predicate Count or Sum) includes any false contribution. Thorough theoretical analysis and extensive simulation study show that our algorithm outperforms other existing approaches. Irrespective of the network size, the per-node communication overhead in our algorithm is O(1).