Composite trust-based public key management in mobile ad hoc networks

Abstract

Public key management in mobile ad hoc networks (MANETs) has been studied for several decades. Yet no single solution has completely resolved well known design challenges resulting from the unique characteristics of MANETs. These challenges include no centralized trusted entities, resource constraints, and high security vulnerabilities. This work proposes a fully distributed trust-based public key management approach for MANETs using a soft security mechanism based on the concept of trust. Instead of using hard security approaches, as in traditional security techniques, to eliminate security vulnerabilities, our work aims to maximize performance by trading off risk (i.e., security vulnerability) for trust. In this work, we propose a composite trust-based public key management (CTPKM) with no centralized trust entity with the goal of maximizing performance (e.g., service availability or efficiency) while mitigating security vulnerability. Each node employs a trust threshold to determine whether or not to trust another node. Each node's decision making using the given trust threshold affects performance and security of CTPKM. Our simulation experimental results show that there exists an optimal trust threshold that can best balance and meet the conflicting goals between performance and security, exploiting the inherent tradeoff between trust and risk.