The Research Of Secure Top-k Query Processing In Two-tiered Wireless Sensor Networks

The architecture of two-tiered wireless sensor networks is known to be indispensable for increasing network capacity and scalability, reducing system complexity, and prolonging network lifetime, which has good prospects for development. Data query is most frequently used in the applications of the wireless sensor networks. In two-tiered wireless sensor networks, the storage node plays such an important role that it is more attractive to adversaries. Once a storage node is compromised, both the privacy of the sensing data and the integrity of query result will be threatened. Secure data query processing in two-tiered wireless sensor networks has attracted more and more attentions.In this thesis, a bucket partition based privacy-preserving top-k query processing scheme, named BPTQ, and an efficient top-k query processing scheme with result integrity verification, named ETQ-RIV, are proposed to protect data privacy and query result integrity in two-tiered wireless sensor networks, respectively. A sensor data submitting protocol and a top-k query processing protocol are described in detail which are used for BPTQ, while a data binding & collecting protocol and a verifiable query response protocol are described for ETQ-RIV. In BPTQ, bucket partition mechanism and encryption technology are introduced to protect the data privacy during storage, transmission and query processing. In ETQ-RIV, based on the keyed-hash message authentication code(HMAC), the base station is capable of verifying the authenticity and integrity of the top-k query result after the verification information is added in the message during transmission.Theoretical analysis and experimental results show that: BPTQ can preserve the privacy of the sensing data and query result, and it consumes less energy of sensor nodes compared with PPTQ, which will prolong the lifecycle of the whole network. ETQ-RIV has simple protocols that are easy for application. In the meantime, it enables authenticity and integrity verification of the top-k query result, and performs better than the existing work in both communication cost and query result redundancy rate.