Efficient and Secure Top- k Query Processing on Hybrid Sensed Data

The ubiquity of mobile devices equipped with various sensors has promoted the advent of a novel data sensing paradigm. Based on the traditional static sensing mode, the mobile sensing (sensor) nodes collaboratively collect data with the static sensor nodes. This large volume of hybrid sensed data is then sent to the storage nodes for flexible management and top-k query services. One crucial security issue is that the compromised storage node may falsify or drop some data during the query processing, which returns fake or incorrect result to the query users. In this paper, we propose an efficient and verifiable scheme (EVTopk) for secure top-k query processing on hybrid sensed data, which is suitable for the tiered hybrid sensing network where mobile nodes exist. The basic idea is to bind each data record, generated by static or mobile sensing nodes, with the corresponding location where it is sensed. Then some verification information is created sequentially, which is submitted along with the encrypted locations and hybrid sensed data for user's verification. The security and efficiency of EVTopk are thoroughly analyzed in theory and evaluated in our experiments, respectively.