Data aggregation applications in wireless sensor networks

Wireless Sensor Networks (WSN) applications are being used in various fields due to numerous advantages that they provide. According to requirements of the applications, the sensor nodes that form WSNs are usually designed in small volumes and for one-time use only. Clustering applications such as HEED or LEACH, which are developed to provide energy efficiency, divide network into inner clusters and make it possible to manage packet transmission through the network. Although clustering applications help to maintain energy efficiency, when considering the typical properties of WSNs, it was understood that we can still improve energy efficiency. With the Data Aggregation approach which is adopted in this thesis, we can eliminate redundant data transmission. Thanks to that, it is possible to obtain energy efficiency up to 70% against standard clustering applications. Security is an another important issue in WSNs. To provide secure communication, data are needed to be encrypted. But in contrast to great advantages that they provide data aggregation approaches do not support standard encryption applications. For this reason, there is a need for an encryption algorithm which can work with data aggregation applications. The Elliptic Curve Cryptograph (ECC) approach, which is adopted in this thesis, allows performing arithmetical operations over encrypted data due to its homomorphism property. Thanks to privacy homomorphism property ECC is an efficient solution for WSNs that allows secure data aggregation. With the proposed ?Eliptik Eğri İle Güvenli Veri Kümeleme (EEiGVK)? Procedure, it is aimed to develop a new approach that can be an integrated solution to two major problems of WSNs, the energy consumption and the security issues.Key Words : Wireless Sensor Networks, Clustering, Data Aggregation, Elliptic Curve Cryptography, Secure Data Aggregation