Aggregation Schemes Based On Homomorphic Encryption In Wireless Sensor Networks

In recent years, for the features such as low cost, flexible networking and easy to deploy, WSNs(Wireless Sensor Networks) are become widely used in daily life, and the data processed are increasingly large. With finite energy resources in sensor nodes, the amount of sensor energy determines the lifetime of the sensor network. The limited battery resources of sensor nodes can be compensated for with data aggregation technology, and hence prolong network lifetime. Many sensor nodes are deployed in harsh environments, so the WSNs may face a variety of attacks, including eavesdropping attacks, replay attacks, Sybil attacks and DoS attacks. Therefore, the design of the sensor network must take security issues into account.The data aggregation schemes in WSNs should be designed for the different security requirements in different application environments, while achieving energy efficient, the network must be able to ensure that it can run properly and safety even in the case of the presence of malicious nodes. This paper summarizes and analyzes the existing secure data aggregation schemes in WSNs, then compares and categorizes these schemes. There are varieties of malicious attacks in network, one secure data aggregation scheme cannot achieve against all attacks at the same time. This paper presents two different secure data aggregation schemes for the different types of attacks in WSNs. With achieving data aggregation energy saving, the schemes also take account of data confidentiality, integrity and other basic security features during data processing. The main work and contributions are as follows:(1) The structure and characteristics of WSNs were analyzed and described in detail, and then we introduced the main applications for WSNs in real-world environments. For the characteristics of WSNs, we concentrated on analyzing the security requirements and security issues in WSNs. Then the important role of data aggregation technology to WSNs applications was described. Finally we systematically compared the existing secure data aggregation schemes in WSNs, summarized the main techniques, the security performance and the possible problems in these schemes.(2) Based on the summarizing and analyzing the characteristics and security features of WSNs, with the consideration of the drawbacks of the hop-by-hop encryption schemes, our work proposed an Integrity verification scheme based on privacy homomorphism data aggregation scheme against the known-plaintext attack and ciphertext-only attack. Using the advantages of privacy homomorphic encryption technology, our work can achieve better end-to-end data confidentiality. With the structure of aggregation TAG-tree, the random detection nodes are used to detect the integrity of the aggregated results to verify whether the aggregators faithfully transmit each data packet. Our work not only reduces the data communication overhead, but also improves the accuracy of data transmission.(3) After summarizing and analyzing the existing secure data aggregation schemes in WSNs, secure data aggregation with fully Homomorphic encryption scheme(FESA) is proposed. For the shortages of privacy homomorphic encryption technology, we first applied the full homomorphic encryption technology into WSNs, achieving stronger data confidentiality protection and guaranteeing unlimited aggregation operations in aggregators. Against the injection attack and Sybil attack, we proposed MFN-group which consists of monitoring node, forwarding node and neighboring node to form the network structure, making false data be detected and discarded when it appears immediately in the processes of data aggregation and forwarding. Thus, the security and efficiency of the entire network are enhanced.