Statistical Detectability of Quantum Cloning Attacks on BB84 Using IBM Qiskit Simulations

Abstract

In this work, we show that even near-optimal quantum cloning strategies fail to undermine the security of the BB84 quantum key distribution (QKD) protocol. Using IBM’s Qiskit framework and implementing a phase-covariant cloning machine on BB84equatorial states, our simulation results indicate a high average clone fidelity (0.854). However, this fidelity is insufficient to avoid statistical detection, as in 200 trials, validating just over 30% of the keys resulted in Eve being detected in over 90% of cases. These results demonstrate that while cloning machines can largely replicate individual BB84 qubits, collective errors introduced across the key drastically increase the odds of being detected, affirming BB84’s robustness under ideal simulated conditions.

Under review at Journal of Student Research