In this paper, the authors explain about the secure data transmission between sensor nodes and aggregator. Security is always a booming in Wireless Sensor Networks (WSNs). Providing data aggregation while preserving data privacy is a problem in wireless sensor network research. Privacy-preserving data aggregation has emerged as an important concern in designing data aggregation algorithm. Data aggregation while privacy preserving data privacy and security is a main challenging problem in wireless sensor network research. Protecting the data privacy in many wireless sensor network applications is a major concern data aggregation scheme privacy.