Research On The Physical Layer Secure Routing In Multihop Wireless Networks

Network security is one of the most important problems that all communication networks have to deal with.Following the sharp rise of demand for wireless network applications at present,wireless network security is facing new challenges.Almost all secure communication in wireless network employs the traditional cryptographic algorithms at present.With the rapid development of computing technology,such as supercomputer and cloud computing,the computing capability of the eavesdroppers is enhanced dramatically.The cryptography-based method based on the computational complexity is facing more and more threats.And the traditional cryptography-based method is no longer satisfying people's demand for information security.Unlike the traditional cryptography-based method,physical layer security provides another way to solve the problem of communication security.The concept of physical layer security communication is based on the Shannon's information theory.In a communication system which employs the traditional cryptographic algorithms,eavesdropper is faced with messages which containing encrypted information.In a communication system which based on physical layer security,the problem which eavesdropper faced with is not able to get any information.As a form of wireless communication network,Wireless Mesh Network has a wide range of applications at present.WMN communication is based on multi-hop transmission.This paper focuses on the routing algorithm based on physical layer security in WMN.The main contributions of this paper are summarized as follows:Firstly,for a given path from the source to its destination,we propose mathematical analytic expressions of secure outage probability(SOP)for both multihop networks with decode-and-forward(DF)and randomize-and-forward(Ra F)relaying.We adopt the end-to-end SOP as a secrecy metric to characterize the physical layer security performance.Having the analytical SOP expressions enables us to analyze and compare the performance of different secure routing solutions.Secondly,based on the analytical SOP expressions of the WMN we proposed,we develop a revised Bellman-Ford routing algorithm in order to finding the lowest SOP path between any given source-to-destination pair.The level of computational complexity of the algorithm we developed is much lower than the level of the exhaustive search.Thirdly,simulations are conducted to verify the analytical results on SOP and show the effectiveness of the routing algorithm we developed in this paper.Then we compare the performance of different parameters on security.Finally we compare the performance of the routing algorithms we proposed for both multihop networks with DF and RF relaying on security.