IHKEM: A post-quantum ready hierarchical key establishment and management scheme for wireless sensor networks

Wireless Sensor Networks (WSNs) are increasingly embedded in mission-critical infrastructures, yet their constrained resources make conventional cryptographic solutions unsuitable. Existing hierarchical key management schemes, such as the RB method, provide partial protection but remain vulnerable to impersonation, replay, and node capture attacks. To address these challenges, we propose IHKEM (Improved Hierarchical Key Establishment and Management), a lightweight yet robust protocol that integrates symmetric and asymmetric primitives for mutual authentication, dynamic session key establishment, and end-to-end confidentiality. Unlike static key distribution methods, IHKEM eliminates unilateral key control, employs nonce- and timestamp-based validation for replay resistance, and supports adaptive key refreshing to preserve forward and backward secrecy. Extensive NS-2.35 simulations demonstrate that IHKEM significantly reduces energy consumption (∼15–20% over RB), improves flexibility against node compromise (>80% uncompromised links under 15% capture), extends network lifetime (delayed FND/HND thresholds), lowers memory footprint (∼20–25% reduction), while incurring only ∼3% higher overhead compared to lightweight schemes such as SEE2PK. Beyond its immediate gains, IHKEM’s modular architecture ensures post-quantum readiness, enabling seamless integration of lattice-based key encapsulation and signature schemes. This work bridges the gap between efficiency, resilience, and long-term cryptographic sustainability in WSNs.