A new dynamic updating key strategy based on EMSA in wireless mesh networks

In the security protocols of Efficient Mesh Security Association(EMSA), the key updating strategy is an effective method to ensure the security of communication. For the existing strategy of periodic automatic key updating, the PTK(Pairwise Transit Key) is updated through the complex 4-way handshake to produce each time. Once the update frequency of the PTK is faster, it will have a greater impact on throughput and delay of the network. On this basis, we propose a new strategy of dynamic key updating to ensure the safety and performance of wireless mesh networks. In the new strategy, mesh point(MP) and mesh authenticator(MA) negotiate a random function at the initial certification, and use the PTK which is generated by the 4-way handshake as the initial seed. When the PTK updating cycle comes, both sides generate the new keys using the random function, which do not have to generate a new PTK by complex 4-way handshake. The analysis of performance compared with existing strategies showed that the dynamic key updating strategy proposed in this paper have a larger increase in delay and throughput of the network.