Authenticated secure communications in mobile ad hoc networks

Providing adequate levels of security in wireless ad hoc networks is a challenging issue due to increases in both resource constraints and threat levels in this type of network. Any solution therefore requires robust security schemes without compromising performance. In this paper, we present a security scheme that uses pairwise symmetric keys, computed non-interactively by the nodes, which reduces communication overhead. We use identity-based keys that do not require certificates and simplify key management. Our system requires a minimum number of keys to be generated by the third party as compared to conventional pair-wise schemes. In addition, we propose an authenticated broadcast scheme based on symmetric keys and a corresponding signature scheme to minimize bandwidth overhead. We allow nodes to generate their broadcast keys for different groups and propose a collision-free method for computing such keys.