University of Technology Sydney. Faculty of Engineering and Information Technology.We as an advanced civilization rely on communication networks for a lot of important tasks. They are used to share information between vital systems, provide us with our pin-point location, access various digital resources and to stay connected with each other. Due to its necessity and enormity, maintaining and securing such a communication medium is an important task. As most communication networks rely on centralized systems, they are bound by the control of a central entity and are unable to keep up with the current growth of the network and advancements in electronic devices. The next step in an inter-connected world requires a decentralized distributed system that can also provide high levels of security. One possible solution is a dynamic distributed wireless mesh network as it provides all the features of a traditional network along with the flexibility of wireless communication and an infrastructure less distributed setup. The network can be created by connecting mobile or stationary devices together using wireless communication devices (such as smartphones, laptops, hot-spots, etc). As the network is created by multiple devices, it would not break-down if some of the devices were disabled. On the contrary, as the network uses hopping for message transmission using dynamic routes, it can self-heal by creating alternate routes if a device was to fail. As the workings and features of a dynamic mesh network differ from the traditional network, it also requires a modified security framework that can provide high levels of security whilst taking benefit of the dynamic mesh network’s unique features.
This thesis investigates the problems and limitations linked to secure dynamic wireless mesh networks and how they can be improved upon. In addition to the routing protocols used and how they can be improved upon, the thesis also elaborates on the various security concerns with such networks. As distributed networks aren’t dependent on a central entity, enabling various security features such as authentication are a major challenge. In addition to the decentralized nature of the networks, a single security scheme would not be able to cover the various types of requirements a given scenario in the network might have. Along with authentication, providing end-to-end encryption is also an important component towards ensuring the data travelling through the network is secure and not tampered with. Encryption is also essential in a dynamic wireless mesh network as the data transmitted travels through multiple devices on the network before reaching the destination node and can be easily compromised if not secured. With such an importance of encryption, the network also requires a key management and distribution framework. As traditional network uses a centralized system for maintaining and distributing cryptographic keys in the network, it is a big challenge to implement the same in a distributed network with minimal dependence on a central entity. The key exchange must consider the nature of the network and accordingly incorporate improvements to be able to function in a distributed network. This thesis explores the above areas to propose a new network model for a secure dynamic wireless mesh network including a new routing scheme and a security framework comprising a hybrid encryption scheme, a hybrid authentication scheme and an improved key exchange and management scheme. This thesis demonstrates that our solutions not only strengthen and secure the dynamic wireless mesh networks but also significantly improve the performance and efficiency as compared to existing approaches