Abstract
In this paper we present a secure data aggregation scheme in Wireless Sensor Networks for IoT. The proposed method encrypts the sensor data by our elliptic-curve based seed exchange algorithm and Hilbert-curve based data transformation. As a result, it is very difficult to trace a real value even though attackers overhear the sending data. Through our performance analysis, we show that our data aggregation scheme outperforms the existing methods in terms of energy efficiency and privacy preservation.