Handling Attacks on Routing Protocols in Ad hoc Networks
Sandhya Khurana · 2011
Mobile ad hoc networks (MANET s) have been proposed to support dynamic scenarios where no infrastructure exists. Each node in the network acts as a host as well as a router and, forwards traffic to other nodes. MANET s can be set up quickly and at low cost in contrast to infrastructure networks which may be wired or wireless. Military networks like air force networks between airplanes and navy networks between ships, network between various sites in emergency disaster relief and interaction between attendees at a meeting are some of the common examples where ad hoc networks are preferred. Efficient and secure routing is the heart of any network and is especially challenging in an infrastructure-less network where participating nodes are portable and mobile. Routing in MANET s is vulnerable to threats since communication in ad hoc networks is dependent upon the cooperation of nodes for forwarding packets. Therefore, it is a challenge for researchers to embed solutions to assuage attacks in existing routing protocols. Passive eavesdropping, active impersonation, message replay and message distortion are some of the common attacks in ad hoc networks. Our work contributes towards mitigating attacks on routing protocols in ad hoc networks. We provide solutions to handle three types of attacks namely blackhole attack, wormhole attack and attack due to selfish nodes. Network performance is known to degrade significantly in presence of blackhole and selfish nodes. Wormhole tunnels have a severe impact on the neighborhood discovery process which forms the backbone of routing in MANET s. It is also known to partition the network by making one side of the network unreachable from the other side. Since no protocol is known to handle all types of attacks, we also propose a solution to compute a path that is exposed minimum to the nodes under the danger of attack. We first propose a scheme to mitigate both blackhole attack and attack due to selfish nodes in a single solution. The proposed algorithm also assuages multiple blackhole nodes in the network. No algorithm is known to handle both blackhole nodes and selfish nodes simultaneously. Our solution improves upon the existing solutions to handle blackhole/ selfish node in terms of overheads and hardware requirements. Next, we present an end-to-end solution to alleviate the effect of wormhole attack. This solution also improves upon the existing solutions in terms of overheads and infrastructure requirements. Lastly, we present an algorithm to find a path that is farthest from the nodes under the danger of attack. The problem has hot been addressed in the context of ad hoc networks earlier. In a highly mobile environment of MANETs it is legitimate to look for a path where an intruder can not get in easily. The path is computed in optimal O(|P |) time where |P | is the length of the path. Assuming that the packets are received from the shortest path first, the algorithm computes a shortest such route.