Neighbor Information Sensing Based Secure Time Synchronization In Industrial Wireless Sensor Networks

Industrial wireless sensor networks are widely used in industrial detection and control field because of their low maintenance cost and convenient networking.Time synchronization is an essential technology for industrial wireless sensor networks,and without time synchronization nodes cannot collaborate with each other.However,industrial wireless sensor networks are vulnerable to attacks by physical nodes and communication links,and security becomes a key factor in the design of time synchronization algorithms that cannot be ignored.In particular,intelligent sybil attacks undermine network time synchronization by spreading illegitimate messages through disguising the identity of multiple nodes,which is more damaging in a centralized network topology environment.This thesis researches the various types of attacks that exist in industrial wireless sensor networks,analyzing the failure of classical centralized network algorithms under a variety of attacks,which provides a theoretical basis for subsequent research.In order to ensure the secure time synchronization in centralized network,this thesis studies the secure time synchronization algorithm,and carries out the corresponding theoretical analysis,and then constructs a new network topology based on this algorithm.The main contents of this thesis are as follows:(1)A new neighbor information sensing secure time synchronization algorithm is proposed for existing centralized time synchronization protocols that lack defense mechanisms against intelligent sybil attacks.The core idea of the algorithm is to fuse the network structure and clock state information,and use the public neighbor transmitting mechanism to automatically filter the illegal time information.The nodes estimate clock compensation values utilizing least squares linear regression based on the local time and difference of received messages instead of establishing a list of times when packets are sent and received.The simulation results show that the algorithm has strong resistance to sybil attacks and message manipulation attacks in centralized network environment.(2)Secure time synchronization algorithm for network topology construction and centralized network topology synchronization error accumulation with number of hops in a large-scale network environment.A new algorithm for constructing centralized network topology is designed according to the neighbor node forwarding mechanism.The algorithm firstly filters the source nodes,secondly constructs the information tables of 1-hop and 2-hop neighbors,and then selects the 1-hop and 2-hop neighbors with the largest fitness as the reference forwarding node and synchronous master node,respectively,based on the energy and distance parameters as the fitness,and analogously constructs the network topology.Simulation experiments show that the algorithm can successfully build a network topology and,compared with the network topology constructed by the flooding time synchronization algorithm,it ensures the security of network time synchronization while reducing the total number of network hops and improving the time synchronization accuracy.