An ad hoc network is a collection of wireless computers (nodes), communicating among themselves over possibly multihop paths, without the help of any infrastructure such as base stations or access points. Although many previous ad hoc network routing protocols have been based in part on distance vector approaches, they have generally assumed a trusted environment. In this paper, we design and evaluate the Secure Efficient Ad hoc Distance vector routing protocol (SEAD), a secure ad hoc network routing protocol based on the design of the Destination-Sequenced Distance-Vector routing protocol. In order to support use with nodes of limited CPU processing capability, and to guard against Denial-of-Service attacks in which an attacker attempts to cause other nodes to consume excess network bandwidth or processing time, we use efficient one-way hash functions and do not use asymmetric cryptographic operations in the protocol. SEAD performs well over the range of scenarios we tested, and is robust against multiple uncoordinated attackers creating incorrect routing state in any other node, even in spite of any active attackers or compromised nodes in the network.

this article presents security threats and major solutions from the literature along routing, cooperation enforcement and key management in MANET

Mobile ad-hoc wireless networks are established in improvised environments through the mutual cooperation of its participating nodes. These nodes often operate in a physically insecure environment and, as a result, are vulnerable to capture and compromise. In addition, the nature of the wireless communication medium restricts enforcement of rigourous node memberships and so a number of malicious nodes may also participate in the network. These nodes, in order to snoop or sabotage, can undertake a variety of attacks against the network. Among these, wormhole attacks have unusual significance primarily due to their modus operandi and peculiar attack pattern. In such attacks, two or more malicious colluding nodes create a higher level virtual tunnel in the network, which is employed to transport packets between the tunnel endpoints. These tunnels emulate shorter links in the network and so act as bait to unsuspecting network nodes which, by default, seek shorter routes. The benefit gained by the malicious nodes is that they are able to conduct a variety of attacks against the tunnelled traffic. In this paper, we present a novel trust-based scheme for identifying and isolating nodes that create a wormhole in the network, without engaging any cryptographic means. With the help of extensive simulations, we demonstrate that our scheme functions effectively in the presence of malicious colluding nodes and does not impose any unnecessary conditions upon the network establishment and operation phase. Keywords: Ad-hoc, attacks, network, routing protocol, security, trust 1