# Key Management Scheme Based on Route Planning of Mobile Sink in Wireless Sensor Networks
## 5 Conclusions  
This paper proposes a key management scheme based on dynamic clustering and the optimal route choice for MSs. The scheme carries on dynamic clustering in the network periodically by the PSO algorithm with multi-objective optimization to change cluster heads regularly. It can avoid the early death of the nodes who forward data chronically, so to some extent it can effectively address the problem of energy holes in WSNs. Also we discussed the problem of MS mobile route planning. The movement distance and the probability of route selection are regarded as the optimized goal. As a tradeoff, after appropriately sacrificing the cost of a certain distance, it can ensure that the cached data in the limited storage space can be read in time, and reduce the danger of overwriting or overflowing of the cached data. After fully considering the heterogeneity of resource allocation between the MS and cluster heads, the session key between them could be built by the improved ECDH key agreement method, and the session key between the member nodes and cluster head will be established by a binary symmetric polynomial. The simulation and performance evaluation show that the proposed scheme can provide better resilience to node capture, as well as higher network connectivity and storage efficiency. **Acknowledgments: This work was supported by National Nature Science Foundation of China (No. 61273068), International Exchanges and Cooperation Projects of Shanghai Science and Technology Committee (No. 15220721800). ** Author Contributions: [PERSON] conceived and designed the research and experiments, and contributed as the lead author of the article; [PERSON] and [PERSON] wrote the article; [PERSON] and [PERSON] performed the experiments; [PERSON] contributed to revising and proofreading of the article; [PERSON] gave suggestion and analyzed the data; [PERSON] gave more valuable suggestion to the research, and audited the article. ** Conflicts of Interest: The authors declare no conflict of interest. ** References  
* [PERSON] et al. (2014) [PERSON]; [PERSON]; [PERSON]; [PERSON] A comprehensive study of data collection schemes using mobile sinks in wireless sensor networks. _Sensors_**2014**, 14, 2510-2548. [CrossRef] [PubMed]
* [PERSON] et al. (2015) [PERSON]; [PERSON]; [PERSON]; [PERSON] Dual-stack single-radio communication architecture for UAV acting as a mobile node to collect data in WSNs. _Sensors_**2015**, 15, 23376-23401. * [PERSON] et al. (2010) [PERSON] [PERSON]; [PERSON]; [PERSON] [PERSON]; [PERSON] Wireless multimedia sensor networks: Current trends and future directions. _Sensors_**2010**, 10, 6662-6717. [CrossRef] [PubMed]
* [PERSON] and [PERSON] (2010) [PERSON]; [PERSON] [PERSON] QoSNET: An integrated QoS network for routing protocols in large scale wireless sensor networks. _Comp. Commun._**2010**, 33, 1334-1342. [CrossRef]
* [PERSON] et al. (2008) [PERSON]; [PERSON]; [PERSON]; [PERSON] Rendezvous design algorithms for wireless sensor networks with a mobile base station. In Proceedings of the 9 th ACM International Symposium on Mobile Ad-hoc Networking and Computing, Hongkong, China, 27-30 May 2008; pp. 231-240. * [PERSON] and [PERSON] (2011) [PERSON]; [PERSON] Optimal path selection for mobile sink in delay-guaranteed sensor networks. _Acta Electron. Sin._**2011**, _39_, 742-747. * [PERSON] and [PERSON] (2012) [PERSON]; [PERSON] [PERSON] Grid-based clustering with predefined path mobility for mobile sink data collection to extend network lifetime in wireless sensor networks. _IETE Tech. Rev._**2012**, _29_, 133-147. [CrossRef]
* [PERSON] et al. (2013) [PERSON]; [PERSON]; [PERSON] On reducing delay in mobile data collection based wireless sensor networks. _Wirel. Netw._**2013**, _19_, 285-299. [CrossRef]
* [PERSON] and [PERSON] (2010) [PERSON]; [PERSON] Network-assisted sink navigation for distributed data gathering: Stability and delay-energy trade-offs. _Comp. Commun._**2010**, _33_, 160-175. [CrossRef]
* [PERSON] et al.