Degree Name

Master of Engineering by Research


School of Electrical, Computer and Telecommunications Engineering


A Mobile Ad-hoc Network (MANET) is an ideal network that merely consists of mobiles devices without any pre-established infrastructure. However, the secure communication over a MANET is not straightforward. In this thesis, we present a solution for MANET secure communication. Generally speaking, it covers two main areas, namely key management and secure routing.

In the key management area, we present an idea of adopting certificateless public key encryption (CL-PKE) schemes over mobile ad hoc network (MANET), which have not been explored before. In the current literature, there exists two main approaches, namely public key cryptography and identity-based (ID-based) cryptography. Unfortunately, they both have some inherent drawbacks. To avoid these obstacles, Al-Riyami and Paterson proposed certificateless cryptography systems. In this thesis, we adopt Al-Riyami’s advantage over MANET. To implement CL-PKE over MANET and to make it practical, we incorporate the idea of Shamir’s secret sharing scheme. The master secret keys are shared among some or all the MANET nodes. This makes the system self-organized once the network has been initiated. In order to provide more flexibility, we consider both a full distribution system and a partial distribution system.

In the secure routing area, we present the idea of adopting a reputation system over the optimized link state routing (OLSR) protocol. In the literature, there exists two main routing approaches, namely proactive routing and reactive routing. Several secure reactive routing protocols have beenproposed. However, as far as proactive routing is concerned, few secure protocols are presented, yet they all possess different drawbacks that make them only practical on certain routing protocols. One of major problems is how to determine whether a node is worthy of trust or not. In other networks, for example, peer-to-peer sharing networks, reputation systems are designed to judge users. Unfortunately, they are designed specifically for peer-to-peer systems, while the adoption to MANET is not very straightforward. To this end, we present our Rep-OLSR, which selects routes wisely based on users’ former performance by periodically collecting polling results from neighbour nodes.

Finally, we demonstrate that our solution is robust against several types of attacks. We also test our solution with several simulations. The results of the simulations indicate that our solution efficiently secure the communication with little extra traffic compared with pure MANET routing protocols.

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