The Research Of Privacy-preserving Data Aggregation Scheme In Wireless Networks

Wireless sensor network(WSN)is a new type of sensor network,which is composed of inexpensive nodes,which is responsible for collecting and processing data.WSN can sense network information infinitely for distributed processing and improve data accuracy,such as seismic data,sound data temperature,humidity and so on.WSNs can work for many aspects of our lives,which can help us improve understanding the physical world more deeply,more widely,more accurately and more promptly,and enhance remote monitoring and control capabilities.With the rapid development of WSNs,security problems have aroused wide concern.In this thesis,we study privacy-preserving data aggregation schemes in WSNs.Some recent approaches include perturbation based privacy-preserving schemes,secure multiparty computation based privacy-preserving schemes,homomorphic encryption based privacy-preserving schemes and polynomial regression based privacy-preserving schemes.In this paper,we focus on the privacy-preserving based on polynomial regression and homomorphic encryption and propose new schemes.The main contributions of this thesis are:Firstly,we propose a PRDA+ protocol,first of all,nodes fit sensing data into polynomial functions by least squares,and send the coefficients of polynomial functions to the aggregator by replacing the original data,greatly reduce the amount of communication.moreover,in our scheme,nodes and the base station will deploy private keys in advance,random number generator generate random numbers through the private keys and encryption,protect the privacy of data more better.Finally,we use the correlation between the two metadata to compare aggregation data after decryption to achieve the integrity of the data protection.Secondly,we propose a weighted average aggregation scheme which can be verified(VAAS),according to the difference of every user's information,we use the concept of the weight and set a corresponding weight for each sensor node.In the process of information transmission,if we use encryption to ensure privacy of data,there are shortcomings.If the sender has already sent a message but deny this behavior.Although the data transmission process is private,we can't prove the identity of the sender who sends this message.This is not helpful for communication management.To address this problem,we use the ElGamal digital signature to authenticate sensor nodes.Before the aggregation operation,it is required to verify the node's digital signature.The signature verification algorithm makes the scheme resistant to data tampering and deniability and tracing data sources.