Wormhole attack is a serious security issue in Mobile Ad hoc Network (MANET) where malicious nodes may distort the network topology and obtain valuable information. Many solutions, based on round trip time, packet traversal time, or hop-count, have been proposed to detect wormholes. However, these solutions were only partially successful in dealing with node highspeed mobility, variable tunnel lengths, and fake information by malicious nodes. To address those issues, this paper proposes a novel multi-level authentication (MLA) model and protocol (MLAMAN) for detecting and preventing wormhole attacks reliably. MLAMAN allows all intermediate nodes to authenticate control packets on a hop-by-hop basis and at three levels: 1) the packet level where the integrity of the packets can be verified, 2) the node membership level where a public key holdermember can be certified, and 3) the neighborhood level where the neighborhood relationship between nodes can be determined. The novelty of the model is that it prevents malicious nodes from joining the network under false information and pretense. It detects wormhole nodes effectively under various scenarios including variable tunnel lengths and speeds of moving nodes. The effectiveness of our approach is confirmed by simulation results through various scenarios.

Request route flooding attack is one of the main challenges in the security of Mobile Ad Hoc Networks (MANETs) as it is easy to initiate and difficult to prevent. A malicious node can launch an attack simply by sending an excessively high number of route request (RREQ) packets or useless data packets to nonexistent destinations. As a result, the network is rendered useless as all its resources are used up to serve this storm of RREQ packets and hence unable to perform its normal routing duty. Most existing research efforts on detecting such a flooding attack use the number of RREQs originated by a node per unit time as the threshold to classify an attacker. These algorithms work to some extent; however, they suffer high misdetection rate and reduce network performance. This paper proposes a new flooding attacks detection algorithm (FADA) for MANETs based on a machine learning approach. The algorithm relies on the route discovery history information of each node to capture similar characteristics and behaviors of nodes belonging to the same class to decide if a node is malicious. The paper also proposes a new flooding attacks prevention routing protocol (FAPRP) by extending the original AODV protocol and integrating FADA algorithm. The performance of the proposed solution is evaluated in terms of successful attack detection ratio, packet delivery ratio, and routing load both in normal and under RREQ attack scenarios using NS2 simulation. The simulation results show that the proposed FAPRP can detect over 99% of RREQ flooding attacks for all scenarios using route discovery frequency vector of sizes larger than 35 and performs better in terms of packet delivery ratio and routing load compared to existing solutions for RREQ flooding attacks.

The physical effects happening on the transmission routes in ad hoc networks influence the network performance seriously. These impacts decrease the quality of transmission, especially ad hoc networks with the wide area and high node density. This paper focused on investigating the routing techniques in ad hoc networks taking into account the quality of transmission. Thence, we proposed an improved routing algorithm of DSR based on the cross-layer model in combination with the static agent. The objective of the proposed algorithm is to improve the quality of the transmission signal, reduce the blocking probability of the data packets due to the unguaranteed quality of transmission.

Abstract. Ad hoc On-demand Distance Vector (AODV) is a reactive routing protocols used popularly in Mobile Ad hoc Network. AODV is target of many Denial of Service (DoS) attack types, such as Blackhole/ Sinkhole, Grayhole, Flooding and Whirlwind. There are some published researches to improvement AODV for security goal using digital signature, for example, SAODV and ARAN. However, they have some weakness that a malicious node can attack SAODV by using fake keys and both of SAODV and ARAN routing protocols can not detect wormhole nodes under hide mode. This article proposes a Trust Authentication Mechanisms (TAM) which uses public-key cryptography RSA and digital certificates (DC) based on X509 standard. TAM allows an intermediate node authenticates a preceding nodes by checking all control route packets through 3 steps: (1) Digital certificates; (2) actual neighbors; and (3) packet integrity authentications. The simulation results in NS2 show that TAM can successfully detect and prevent to 100% malicious nodes using fake keys and above 99% (the mistaken rate below 1.0%) wormhole nodes under hide mode for all mobility scenarios where there are nodes move with 30m/s maximum speeds and variable tunnel lengths.

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