**6. Conclusion**

This chapter presented four key management schemes and also security protocol for WMNs. First, Shamir's scheme was a popular method which was used for distributing the keys. The second scheme called SSKM was an improvement of Shamir's scheme by generating different keys in different period as well as using discrete logarithm algorithm to transport the key in a secret way. The third method called HSTMK utilized a key negotiation routine to solve the problem of compromised node. This one also divides initialization phase into four sub-phases to reduce the time requirement and increase the security level. Finally, in our scheme, we establish secured communication sessions between nodes so they can hide their private keys from the other except the requester. That means not only data but also keys were encrypted by combining our scheme with AES encryption. We also use the real-time value to constantly change each node's private key. This has caused great difficulty for anyone who wants to find out private keys of WMN. Comparing with existing security protocols and schemes shows that our scheme is simple to deploy, and it has a better security.

There remain some problems that should be addressed for this security protocol. We need to reduce the amount of the calculations for the proposed protocol which is deployed on routers with small flash memory. Besides, the WMN structure needs to be improved in order to make the system model work efficiently. Thus, these considerations would be developed in the future work.
