Merging the wireless infrastructure network with the wireless mobile ad-hoc networks constitutes hybrid wireless networks (HWNs). Quality of service (QoS) demands are available with the help of HWNs. However, these networks are subjected to many types of attacks because of their open wireless medium. To enhance the security of HWNs, it is necessary to provide secure routing protocols. Several routing protocols have been proposed for HWNs, one of them is the quality of service-oriented distributed (QOD) routing protocol. In this paper, two security mechanisms have been proposed for the QOD protocol. The first mechanism is used to protect transmitted data in the network using asymmetric and symmetric cryptography. The second mechanism has been proposed to enhance the security of the QOD routing protocol using keyed hash message authentication code (HMAC). The second security mechanism assumed that there is a secret key shared between each pair of neighbor nodes. Also, asymmetric cryptography is used to exchange the secret key. The secret key is used to include the message authentication code (MAC) for each message exchanged between the neighbor nodes. A network simulator NS2 is used to simulate our proposed schemes.

Hybrid <span>wireless networks (HWNs) are resulted from the integration of a mobile Ad hoc networks (MANET) and an infrastructure wireless networks. These networks have received increasing interest from researchers for their superior performance and reliability. Packet routing protocols in hybrid wireless networks are important to increase the capacity and scalability of these networks, therefore, several routing protocols have been proposed. Routing protocols in HWNs are designed and implemented from combining <span>the cellular transmission mode with the Ad hoc transmission mode. To route a message to the intended recipient of the sender, hybrid wireless networks use multi-hop technology. However, the source node needs relay nodes, which may be either adjacent nodes or base stations depending on set of parameters like bandwidth, load balancing, or the nearest node. This paper explores routing protocols for hybrid wireless networks and the techniques to enhance the security, performance, and capacity of these routing protocols.</span></span>