Data fusion techniques reduce total network traffic in a wireless sensor network, since data fusion can integrate multiple raw data sets into one fused data set. However, the security or assurance of the data requires more processing power and is an important issue. Increasing the security of the fusion data increases factors such as power consumption, and packet overhead. Therefore any data fusion assurance scheme must be power efficient as well as secure. There are currently several methods of data fusion assurance that have been proposed. Therefore, this paper looks at the current data fusion assurance methods and proposes new schemes focused on reducing power consumption. In this paper, several data fusion assurance schemes are also compared to determine which scheme is the most energy efficient.