Design and Implementation of a Hybrid Cryptographic Framework for Quantum-Resilient and Interoperable Secure Communication

As quantum computing technology progresses rapidly, conventional cryptographic methods like ECDH and RSA are increasingly at risk of being compromised by future quantum attacks. To tackle this issue, our study investigates a hybrid key exchange method that merges classical and postquantum cryptographic techniques, providing robust long-term data protection. The research encompasses two separate systems: one that uses DH in combination with Kyber and another that integrates ECDH with Kyber. These systems were created using socket programming and the FastAPI framework, respectively, and were evaluated in virtual environments to mimic actual communication scenarios. Performance analysis was carried out with Wireshark along with practical metrics such as encryption and decryption durations. The findings indicate that this hybrid method not only strengthens defenses against quantum threats but also sustains practical efficiency, highlighting its promise as a secure key exchange solution for future versions of TLS 1.3 and beyond.