DAK-DSR: Dynamic Authentication-Key Update and Challenge–Response for Secure Dynamic Source Routing in Mobile Ad Hoc Networks

Abstract

Mobile Ad Hoc Networks (MANETs) must achieve routing security without depending on infrastructure that is continuously available, yet static or inadequately managed shared secrets can introduce replay, compromise-recovery, and key-management vulnerabilities. This paper presents DAK-DSR, a Dynamic Authentication-Key extension for Dynamic Source Routing (DSR). DAK-DSR integrates mutual nonce-based challenge–response with a forward-evolving HMAC-SHA-256 key update that is tied to node identities, a digest of the authenticated DSR route transcript, and a session epoch that increases monotonically. A two-phase key COMMIT/CONFIRM exchange blocks unilateral key advancement, and a bounded previous-key recovery window enables operation under packet loss and route changes without requiring a full restart of the complete bootstrap. The specification covers bootstrap trust, key lifetime, revocation, nonce state, replay windows, clock-skew tolerance, route-error recovery, and assumptions about collaborative attackers. A reproducible Monte Carlo protocol-level simulation is used to assess 50-, 100-, and 200-node networks, six attack categories, malicious-node proportions from 0–40%, and 30 independent runs per condition. For 100 nodes with 20% black-hole nodes, the model reports mean Packet Delivery Ratios (PDRs) of 53.4% for DSR, 75.4% for DSR+Integrity, and 91.3% for DAK-DSR. The security improvement comes with added authentication, routing, and energy overhead; consequently, the findings are understood as a security performance trade-off rather than a guaranteed performance increase. The proposed design addresses key-update, replay-resistance, synchronization, scalability, and reproducibility issues while providing a structured authentication mechanism for secure DSR operation in MANETs.