  WiMAX is a promising technology that provides high data throughput with low
delays for various user types and modes of operation. These advantages make
WiMAX applicable both for infrastructure purposes and end-client usage. Since
WiMAX is presented as a network framework and a last-mile technology, it is
believed to be capable of handling a wide range of usage scenarios. For
example, while the end users have an opportunity to use WiMAX as the primary
connection medium for acquiring services such as on-demand video streaming,
VoIP connections and mobile bank transactions, the service providers may use it
for data relaying purposes among access points. To meet the technical
requirements of these various scenarios, majority of the WiMAX research has
been conducted on physical and MAC layers; however little has been invested in
a comprehensive and efficient security solution, which has resulted in a wide
range of security weaknesses and reactive solutions. Many security problems
remain to be addressed in different modes and for different user types even in
the final security standard of WiMAX, PKMv2. Mobile multi-hop relay (MMR) WiMAX
networks have attracted lots of interest in wireless communication industry
because of its scalable coverage, improved data rate and relatively low cost.
Even with the additional security functionalities security of MMR WiMAX network
is the main challenge because messages have to be transmitted through one or
more relay stations, which makes it more difficult to ensure the authenticity
of messages and entities involved in the transmission. In this thesis, we
present a hybrid security solution to overcome the security problem of rogue
station (BS/RS) attack and denial of service attack (DoS) in MMR WiMAX.
