# Node-Based QoS-Aware Security Framework for Sinkhole Attacks in Mobile Ad-Hoc Networks
## 1 Introduction  
A mobile ad hoc network (MANET) is a self-organizing and self-healing autonomous system that consists of a loosely connected set of self-configuring nodes connected via a wireless medium. MANETs have become one of the most prevalent areas of research in recent years because of the challenges they pose to the related protocols and are still regarded as an emerging technology that enables network users to interact without any central infrastructure regardless of their geographical location. That is why it is sometimes referred to as an infrastructure-less network [1]. MANETs have been an active area of research for the last few years and their growth is promoted by the urgent need to provide the users with networks that are convenient to use and manage [2]. MANETs are primarily useful in military and other tactical applications such as emergency rescue or exploration missions [3]. Their existence stretches back to the 1970s where they were used in the military, meaning that they are not a new concept, and their commercial success has been due to advances in wireless technology. Standards have been developed for routing in MANETs. The IETF (Internet Engineering Task Force) regulates the new group for MANETs. The IEEE standard 802.11 has contributed to research interest in MANETs [1]. What contributes to their continued growth is the making of smaller and faster devices and this makes MANETs the fastest growing networking area. The mobility of nodes, however, is rapid and unpredictable over time. MANETs, like all wireless networks, are more vulnerable to attacks and weaknesses as compared to wired networks. The limitations of the wireless medium become especially severe in multi-hop networks, where multimedia streams aresubject to the aggregate effect (e.g., packet drop and propagation delay) of each link along with a node-to-node path. The mobility of a node can cause frequent route breaks in MANETs. Updating routes can be time-consuming, thus packets might for shorter periods be lost in bursts since they are sent on non-working routes [4]. The network must be less prone to security attacks to achieve an acceptable QoS as security vulnerabilities reduce the QoS of MANETs. The biggest challenge in MANETs is the lack of a robust security solution that can protect them from routing attacks. The design solutions needed are not supposed to cause resource constraints such as bandwidth and battery power. The \"self-organizing\" functionality of MANETs can be their greatest advantage as well as their security weakness as it leaves room open for both passive and active attacks. There are many vulnerabilities poised by MANETs of which some are caused by their dynamic topology, limited power supply, limited bandwidth, and scalability. Existing architectures adopted from wired networks cannot be applied directly to MANETs because of the above vulnerabilities, hence there is need to design a robust security framework that will be solely implemented on MANETs. Any QoS-aware security framework to be developed must seek to achieve security goals, i.e., availability, integrity, anonymity, authentication, and confidentiality. To achieve a secure and QoS-aware network, a customer-designed security protocol must be implemented [4]. The problem with MANETs is that they are not well known for having combined solutions to security and QoS-based because of their dynamic nature. Therefore, this work focuses on sinkhole attacks through protocol modification to achieve good security detail without compromising the QoS in real-time. The leading contribution of this paper to the existing body of knowledge in MANETs is bridging the gap between security and QoS by addressing the challenges in sinkhole attacks which affect not only the security of the network but also its performance. Therefore, the paper seeks to present a QoS-aware framework that is designed and evaluated to directly deal with sinkhole attacks in MANETs.