Privacy and Integrity Preserving Top-k Query Processing for Two-Tiered Sensor Network.Privacy and integrity have been the main road block to the applications of two-tiered sensor networks.The storage nodes, which act as a middle tier between the sensors and the sink, could be compromised 

and allow attackers to learn sensitive data and manipulate query results.

Prior schemes on secure query processing are weak, because they reveal non-negligible information, and therefore, attackers can statistically estimate the data values using domain knowledge and the history of query results.In this paper, we propose the first top-k query processing scheme that protects the privacy of sensor data and the integrity of query results.

 To preserve integrity, we propose a data partition algorithm to partition each data item into an interval and attach the partition information with the data. 

 

The attached information ensures that the sink can verify the integrity of query results.Prior schemes on secure query processing are weak, because they reveal non-negligible information, and therefore, attackers can statistically estimate the data values using domain knowledge and the history of query results.