Research On Techniques Of Data Aggregation And Query With Privacy-Preservation In Wireless Sensor Networks

Wireless sensor networks(WSNs)are composed of a large number of sensor nodes which form a multi-hop ad hoc network through wireless communication,where these nodes are deployed in the physical world to cooperatively monitor physical or environmental conditions.WSNs have very broad application prospects in environmental monitoring,medical treatment and military field surveillance.Due to the characteristics of resource-constrained and battery-powered sensors,energy consumption is always a major concern in WSNs.Data aggregation is an essential technique to reduce the communication overhead and energy consumption.Data query is an important operation mode in WSNs.However,wireless sensor nodes have weak resistance to external attack,and thus WSNs will be confronted with a serious privacy threat,which is a key factor in restricting the further application of WSNs.Therefore,it is of great importance to design privacy-preserving data aggregation and query schemes.In this paper,based on the research into energy consumption and privacy of data aggregation and query in WSNs,we design a series of privacy-preserving data aggregation and query algorithms.Besides,we analyze and verify the security and energy consumption of the proposed algorithms.Our contributions in this paper are:(1)With regard to WSNs,in the the existing privacy-preserving data aggregation algorithms,sensory data privacy is achieved through encryption technology.Obviously,these data aggregation algorithms will cause great latency and energy consumption because of a large number of encryption/decryption operations.In light of the above problem,this paper proposes an Energy-Efficient and Scalability Secure Data Aggregation(EESSDA),in which a secure channel is established between each sensor and its neighbor(that is,the two sharing a common random number)for transmitting message with no need of encrypting private data.Theoretical analysis and simulation results show that EESSDA is of lower communication overhead,more efficient and accurate,and better privacy preservation and scalability than existing schemes.(2)With regard to dynamic WSNs,the existing privacy-preserving data aggregation algorithms rely on certain network topology structure and thus consume large amounts of energy.Taking into the above problem into consideration,this paper puts forward a secure and energy-efficient spatial window data aggregation algorithm for sensor networks(SESDA).SESDA is an itinerary-based algorithm to achieve data aggregation.Owing to the well-designed itinerary for aggregate request propagation and data aggregation,SESDA is not susceptible to network topology and thus suitable for sensor networks with network topology transients,which hence improves energy efficiency.SESDA involves five phases: Design of Itineraries,Initialization,Request for Data aggregation,Dataaggregation and Return of Data aggregation results.Furthermore,in consideration of length of itineraries in proportion to delivery delay,this paper proposes a Privacy-Preserving and Concentric-Circle Itinerary-Based Data Aggregation Algorithm(PCIDA).Parallelly performing data aggregation along concentric circles,PCIDA greatly shortens itineraries,making the data aggregation with small delivery delay.Theoretical analysis and experimental results show that PCIDA has low communication overhead and energy consumption,high safety and accuracy.(3)With regard to privacy-preserving continuous data aggregation in WSNs,the existing ggregation algorithms focus on snapshot secure data aggregation,so they are not suitable for continuous data aggregation in view of traffic and energy consumption.This paper proposes a Privacy-Preserving and Energy-Efficient Continuous Data Aggregation Algorithm(PECDA).PECDA reduces traffic by taking advantage of temporal correlation of the sensory data and the threshold which can determine transmission of current sensory data.In addition,PECDA makes full use of secure channels to ensure data privacy to counter dramatic energy consumption caused by heavy encryption/decryption operations and thus significantly reduces energy consumption and prolongs the lifetime of network.Experimental results show that PECDA provides good performance in communication overhead and energy consumption.(4)With regard to Two-tiered Wireless Sensor Networks,storage nodes collect data from sensor nodes and answer the queries from the Sink,becoming attractive targets of attack.The existing privacy-preserving range query algorithms take large communication cost to verify the validity and integrity of sensory data.Hence,this paper presents two safe range query schemes in Two-Tiered Wireless Sensor Networks.One is Safe Verifiable Range Query Algorithm(SafeVRQ),and the other is Secure and Energy-Efficient Range Query Algorithm(SERQ).SafeVRQ utilizes signature aggregation technology to reduce communication cost and SERQ employs the order-preserving encoding technology.Simulation experiments show that two schemes have an advantage in energy consumption and integrity verification.