Secure Hierarchical Data Aggregation in Wireless Sensor Networks: Performance Evaluation and Analysis

Secure data aggregation in wireless sensor networks has two contrasting objectives, i) Efficiently collecting and aggregating data and ii) Aggregating the data securely. Many schemes do not take into account the possibility of corrupt aggregators and allow the aggregator to decrypt data in hop by hop algorithms. On the other hand using public key cryptography for providing end to end security is not energy efficient. In this paper we present and analyze the performance of the secure hierarchical data aggregation algorithm which uses an efficient public key cryptosystem (elliptic curve cryptography) to achieve end to end security. Unlike many other secure data aggregation algorithms which require separate phases for secure aggregation and integrity verification, the secure hierarchical data aggregation algorithm does not require an additional phase for verification. This saves energy by avoiding additional transmissions and computational overhead on the sensor nodes. We present and implement the secure data aggregation algorithm on Mica2 and TelosB sensor network platforms and measure the execution time and energy consumption of various cryptographic functions. We have also simulated our algorithms to analyze how an end to end scheme increases the network life time. We experimentally analyze our algorithms based on parameters like throughput, end to end delay and resilience to node failures.