Abstracts Communications and the Arts

Trust enhanced security framework for mobile ad hoc wireless networks

by Venkatesan Balakrishnan

The advent of wireless communication and the proliferation of handheld devices have significantly advanced the growth of nomadic communications. Capability of these handheld mobile devices to self-organise themselves on fly in the absence of an infrastructure and to extend their communications beyond their wireless radio range have potentially led to the development of Mobile Ad hoc Networks (MANET). Security is one of the most indispensable research areas and plays a central role in determining the success of civilian and commercial mobile ad hoc networks. Unfortunately, mobile nodes struggle to enlist trusted intermediaries for communication with various destinations since trusted intermediaries are a prerequisite to keep those communications alive and free from active attacks. Although few integrated security systems exist for the MANETs, a two-layered (prevention and detection-reaction systems) trust-enhanced security architecture is yet to be seen for the MANETs to the best of our knowledge. The two-layered approach is so required for the prevention and detection-reaction systems to complement each other to deliver a trustworthy, secure, and an operational routing layer amidst the inherent issues. – Therefore this thesis, (a) focuses on the systematic study of the security threats and attacks and, adversaries in the MANETs and accordingly the analysis of the strength of solutions that have been proposed within different categories of security systems, (b) proposes novel techniques to meet the shortcomings of proposed security solutions and thence to develop a realistic two-layered T̲rust E̲nhanced security A̲rchitecture for the M̲ANETs (TEAM). These novel techniques include, (a) an obligation-based fellowship model to motivate cooperation among the mobile nodes, (b) S̲ecure M̲ANET R̲outing with T̲rust I̲ntrigue (SMRTI) that resolves the limitations harboured by related trust models and capitalises all the evidence that are available within the limitations of the M̲ANET for making better routing decisions and, (c) a new secure routing protocol known as Scasec. Furthermore, fellowship model is extended to defend flooding attacks in the MANETs that support anonymous communications. Similarly, SMRTI is extended to incorporate subjective logic with a focus to resolve the notion of uncertainty in the trust relationships established between newly-joining and existing mobile nodes. Finally, the better performance results of all these proposed techniques are demonstrated using varied simulation scenarios.