Combining Entanglement‐ and Non‐entanglement‐Based Quantum Key Distribution Protocol With GHZ State

Quantum key distribution (QKD) protocols fall into two main categories: entanglement‐based and non‐entanglement‐based. Although entanglement‐based QKD offers strong security, it theoretically generates fewer keys with the same number of logical qubits. In contrast, the non‐entanglement‐based method produces more keys but with reduced security. To address these concerns, in this article, we present a novel hybrid QKD protocol that combines both approaches to optimize security and key generation. We introduce a dynamic system that integrates a three‐particle entangled Greenberger–Horne–Zeilinger (GHZ)‐state method with the two‐particle BB84 QKD protocol, using a quantum superposition state to probabilistically switch between them. The GHZ state component leverages strong three‐particle entanglement correlations for enhanced security, while the BB84 component offers simplicity and potentially a higher number of key generation. This protocol was implemented and simulated using IBM’s Qiskit and IBM Quantum Platform; our approach demonstrates 63.48% higher number of key generation compared to the E91 protocol, although 37. 33% lower than the standalone BB84 protocol while maintaining robust security and being less prone to quantum bit error rate (QBER). The results and security discussion show that this combined method effectively balances the trade‐offs inherent in QKD systems, offering a flexible framework adaptable to varying channel conditions and security requirements.