A Security- Centric Evaluation of Classical and Quantum Key Exchange Protocols for Securing the Next Generation of Communication

The current technological advancements in quantum computing pose a threat to traditional key exchange protocols such as Rivest-Shamir-Adleman (RSA), Diffie-Hellman (DH), and Elliptic Curve Diffie-Hellman (ECDH). One of the most important quantum algorithms is Shor's algorithm, which can easily defeat traditional approaches that rely on complex mathematical computations. Instead, the security of the key exchange protocol is provided by quantum cryptographic applications known as quantum key distribution (QKD) protocols, which are based on quantum mechanical principles. QKD provides a secure substitute for key exchange. This paper examines the security of both traditional and quantum key exchange techniques. Using simulation tools such as Qiskit and NetSquid, we model QKD-based communication channels and analyze key rate performance, error rates, and scalability in comparison to classical cryptographic techniques. This paper introduces the emergence of current quantum safe encryption techniques by offering a standardized comparison of key exchange protocols and their applicability to future secure networks. The insights derived from our simulations provide valuable guidance for researchers, industry practitioners, and policymakers in determining the optimal path toward quantum-secure communication infrastructures.