A Comment on the One Step Quantum Key Distribution Based on EPR Entanglement

TL;DR

This paper critically analyzes a recent quantum key distribution scheme based on Bell states, demonstrating its insecurities, incorrect error rate calculations, and its flawed relation to existing schemes, thereby clarifying misconceptions in the field.

Contribution

It provides a rigorous security proof showing the scheme's vulnerabilities and corrects previous error rate calculations, clarifying the scheme's relation to established protocols.

Findings

Li et al.'s scheme is insecure due to information leakage.

All error rates in Li et al.'s paper are incorrect.

Li et al.'s scheme is a flawed modification of existing GV-based protocols.

Abstract

Recently, in Sci. Rep. \textbf{6} (2016) 28767, Li et al., have proposed a scheme for quantum key distribution using Bell states. This comment provides a proof that the proposed scheme of Li et al., is insecure as it involves leakage of information. Further, it is also shown that all the error rates computed in the Li et al.'s paper are incorrect as the authors failed to recognize the fact that any eavesdropping effort will lead to entanglement swapping. Finally, it is established that Li et al.'s scheme can be viewed as an incrementally (but incorrectly)modified version of the existing schemes based on Goldenberg Vaidman (GV) subroutine.