A SCHEME FOR DETECTING AND MITIGATING COOPERATIVE BLACK HOLE ATTACK IN AODV-BASED MANET ROUTING PROTOCOL

Abstract

In the recent years the number of mobile device have significantly increase and has led to many research works particularly in the area of Mobile Ad hoc Networks (MANETs). The network offers mobile access to users with minimal configuration to operate. Despite a large number of investigative and development works on the subject, the research on MANET is considered premature and therefore, many issues need to be addressed. MANET possesses unique characteristics, which includes decentralized infrastructure and dynamic network topology. Nonetheless, such salient features require high flexibility and cooperation between users and herefore, increases the network’s vulnerability to be exploited and denied services. A typical Denial of Service (DoS) in MANET is the Black Hole attack. The Black hole attack can severely degrade the network performance by exploiting the vulnerability of Route Request (RREQ) discovery process in routing protocols such as Ad hoc On Demand Distance Vector (AODV). The design of efficient and reliable scheme to detect and mitigate cooperative Black hole attack is therefore, a major challenge in MANET. The key works on this Research are to investigate the impact of cooperative Black hole attacks on AODV routing protocol and to develop schemes to improve the performance. In the first part of the thesis, an investigative work on the effect of Black hole presence in AODV routing protocol is made. The process in creating Black hole attackers and how they operate using sequence number are thoroughly analyzed. The second part of the thesis presents the proposed scheme, referred to as Reply Supervision Technique (RST). Fundamentally, the RST approach which combines checking and cache technique to count the second RREP message with the highest sequence number and lowest hop count for detecting Black hole node(s). The RST is incorporated with AODV routing protocol to find a secure end-to-end path free of distrustful or malicious nodes. The third part of the thesis presents the validation and result analysis. Simulation results of the base routing protocol is reproduced and compared against the results obtained by previous researcher, In order to ensure that the results obtained using the proposed scheme are credible. Several key performance metrics are used to evaluate the schemes performance using packet delivery ratio, average end-to-end delay, and throughput. The performance differentials of the scheme are analyzed using Network Simulator 2 (NS 2). Results from the simulation experiment show the superiority of the proposed schemes compared to the base protocol under varying cases of network scenario. These attributes that makes wireless network unique and significant, are the same that makes it extremely vulnerable to numerous security attacks. Therefore it is deemed critical to find a possible security solution to mitigate or minimize the effect of Black hole attack in a wireless network is crucial to ensure network functionality.