Energy-efficient secure pattern based data aggregation for wireless sensor networks

Data aggregation in wireless sensor networks eliminates redundancy to improve bandwidth utilization and energy-efficiency of sensor nodes. This paper presents a secure energy-efficient data aggregation protocol called ESPDA (Energy-Efficient Secure Pattern based Data Aggregation). Unlike conventional data aggregation techniques, ESPDA prevents the redundant data transmission from sensor nodes to cluster-heads. If sensor nodes sense the same data, ESPDA first puts all but one of them into sleep mode and generate pattern codes to represent the characteristics of data sensed by sensor nodes. Cluster-heads implement data aggregation based on pattern codes and only distinct data in encrypted form is transmitted from sensor nodes to the base station via cluster-heads. Due to the use of pattern codes, cluster-heads do not need to know the sensor data to perform data aggregation, which allows sensor nodes to establish secure end-to-end communication links with base station. Therefore, there is no need for encryption/decryption key distribution between the cluster-heads and sensor nodes. Moreover, the use of NOVSF Block-Hopping technique improves the security by randomly changing the mapping of data blocks to NOVSF time slots. Performance evaluation shows that ESPDA outperforms conventional data aggregation methods up to 50% in bandwidth efficiency.