Wei Ren Yi Ren Hui Zhang H2S: A Secure and Efficient Data Aggregative Retrieval Scheme in Unattended Wireless Sensor Networks. 450-453 2009 IAS http://dx.doi.org/10.1109/IAS.2009.25 conf/IEEEias/2009 db/conf/IEEEias/IEEEias2009.html#RenRZ09