Mobile Wireless Sensor Network (MWSN) is an emerging technology for attraction of researchers with its research advantage and various application domains. Due to limited resources of sensor nodes such as transmission power, communication capability and size of memory, data aggregation algorithms are the most practical technique that reduces large amount of transmission in this network. Security is an important criterion to be considered because, wireless sensor nodes are deployed in a remote or hostile environment area that is prone to attacks easily. Therefore, security are essential issue for MWSN to protect information against attacks. In this research, we offered an algorithm of secure data aggregation in MWSN based on pair-wise keys technology and hash function. We studied important parameters such as execution time, end-to-end delay and number of storied keys. Results showed that