QUANTUM ENTANGLEMENT SWAPPING CONSENSUS (QESC): A NOVEL FRAMEWORK FOR SECURE DISTRIBUTED AGREEMENT IN QUANTUM NETWORKS

The rapid advancement of quantum computing poses a fundamental challenge to existing consensus protocols in distributed systems, particularly those underpinning blockchain technologies. Classical Byzantine fault-tolerant mechanisms rely on computational hardness assumptions, which are vulnerable to quantum algorithms such as Shor’s and Grover’s. This study proposes a Quantum Entanglement Swapping Consensus (QESC) framework. This novel model uses entanglement swapping and Bell state measurements to enable secure, tamper-evident agree- ments among distributed quantum nodes. Building on quantum key distribution protocols (BB84 and E91) and experimental demonstrations of long-distance entanglement over 103 km of optical fibre [11], we present a theoretical model in which consensus arises from verifiable entangled correlations rather than computational puzzles. We compared QESC with Practical Byzantine Fault Tolerance (PBFT) and evaluated it across latency, fault tolerance, and eavesdropping resistance. The results show that QESC can achieve consensus finality with unconditional security guarantees. The study concludes with a discussion of the hardware limitations and a roadmap for experimental validation.