The intersection of security and sustainability within wireless sensor networks (WSNs) underscores pivotal factors such as energy efficiency, resource optimization, energy waste reduction, and the sustained integrity of network infrastructure. This interplay ensures that deployments are not just efficient but also ecologically sound. WSNs comprise autonomously dispersed sensors linked to battery-powered devices, facilitating wireless data transmission. The optimization of WSNs through Fog and Edge Computing signifies a paradigm shift, diminishing reliance on central cloud servers. This adaptive strategy enhances WSN efficiency across diverse environmental conditions by streamlining data transmission to centralized cloud servers. In cryptographic systems, conventional approaches reliant on mathematical algorithms to secure communication channels encounter vulnerabilities. Quantum cryptography presents a more robust alternative to conventional methods, while post-quantum cryptography (PQC) employs algorithms resilient to both traditional and quantum threats. This chapter introduces a novel approach for mutual authentication and generating session keys in communications between WSN nodes. We use Super singular Hyperelliptic Curve Cryptography (HECC) with a small size by exchange key Diffie-Hellman (DH) to improve security in IoT and WSN. This method provides a promising mix of quantum resistance and integration into conventional approaches.