Through the evolvement of high speed internet, Wireless mesh networks (WMNs) have become one of the most exciting and promising technology for providing high bandwidth features to its users. Along with the advancement of internet, the demand for enhanced capacity and higher bandwidth requirement have strived over time to meet the requirements of the Quality of Service (QoS) in WMNs. Various factors do affect the desired Qos for WMNs. In this thesis, we focus on the key generation scheme for authentication between various entities of the network to establish a secure communication between them, while taking into consideration the QoS requirements set by the benchmark. The key generation scheme discussed here is decentralized and hierarchal in nature which enables a pair of entity (e.g., servers and clients) to share a common key for a secure communication. Moreover, the scheme addresses the issue of the high speed mobility of the clients stations (STAs) from one domain to another domain, i.e. handoff between various inter- domain and intra- domain Access Points (APs). It is necessary that the STAs do not require excessive overhead during the handoff procedure. The schemes discussed enables faster and secure key generation and agreement scheme between the entities of the network during the handoff procedure.
The key generation scheme is distributed in nature. The higher level hierarchy namely the Internet Gateways (IGWs) or the authentication, authorization and accounting (AAA) servers such as RADIUS, generate a multi variate symmetric polynomial function and exchange the information among them such that none of them have a complete knowledge of the entire generated function. As the functions are passed to the lower level hierarchical entities such as Mesh access points (MAPs), the function further reduces providing only legitimate information to them. The process continues until the lowest level of the hierarchy (STAs or clients) is reached where the entities will be able to deduce a secure key for the communication. We refer to this as a distributed mechanism or a distributed authenticated key establishment (AKE) scheme based on hierarchal multi-variable symmetric functions (HMSF). Since, the deduced key is obtained from distributed scheme and below various levels none of the entities have a complete knowledge to reverse engineer the original function used in the generation process. Using the distributed authenticated key establishment scheme the STAs and MAPs could authenticate among themselves without any assistance from the higher hierarchy entities, thus saving the communication overhead time and the delay involved in authentication by getting back to the servers hence maintaining the required QoS.