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In wireless sensor networks, the clustering routing protocol is commonly used for energy efficiency. However, routing protocols without proper security suffer from many security vulnerabilities. Hence, a key renewal scheme based on the clustering routing protocol is proposed. To apply the key renewal scheme with sensor authentication, sensor nodes are first authenticated during the key establishment procedure and then the symmetric key is updated periodically using hash functions. The simulation results show that the proposed key renewal scheme lengthens the network lifetime and has shorter activity time of attackers in spite of increasing the number of compromised nodes.

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In wireless sensor networks (WSNs), hierarchical routing protocol is commonly used for energy efficiency. In particular, the TEEN (Threshold sensitive Energy Efficient sensor Network) protocol is used widely as a basic clustered multihop routing protocol. However, energy efficient routing protocols without proper security suffer from many security vulnerabilities. Hence, in this paper, we propose a hybrid key scheme specially for the TEEN protocol: a symmetric key scheme for the intracluster and a public key scheme for the intercluster. The simulation results show that network lifetime of the proposed hybrid key scheme decreases about 8% than the TEEN protocol and about 4% compared with the TEEN protocol with symmetric key scheme. On the other hand, a hybrid key scheme provides better probability of successful transmission than that of the symmetric key scheme.

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In wireless sensor networks (WSNs), hierarchical routing protocol is commonly used for energy efficiency. However, routing protocols without proper security suffer from many security vulnerabilities. Hence, in this paper, we propose a sensor authentication scheme during key establishment procedure based on clustering routing protocol. It authenticates lower level nodes by using temporal keys which are generated from higher level nodes. The simulation result shows that an authentication probability of member nodes maintains about 99.62% during the whole network lifetime.978-1-4244-8168-2/10/$26.00 ©2010 IEEE

No abstract

In wireless sensor networks (WSNs), time synchronization is basically required to provide time-stamp for the reported events, active-sleep MAC protocols to extend network lifetime, etc. Most synchronization schemes assume that the send time of a packet is captured when packet transmission is just started, and the packet is modified to save the send time before packet transmission is not complete. However, it is difficult for system-performance limited sensor nodes to complete the packet modification in time. In this paper, we propose a synchronization scheme avoiding modification of the outgoing packet (SAMOP) based on the CSMA-CA protocol, where a transmitter and a receiver measure only time instance for the packet with their own local clocks and then a transmitter transfers the time measurements with a subsequent packet. Based on multiple time measurements, SAMOP synchronizes local clocks of both nodes. Simulation results show our SAMOP provides improved accuracy with respect to a synchronizing period.