Cryptanalysis and improvement of the novel semi-quantum secret sharing scheme using entangled states

Abstract

A semi-quantum secret sharing scheme using entangled states was proposed in a recent paper [Mod. Phys. Lett. B 32 (2018) 1850256. https://doi.org/10.1142/S0217984918502561 ]. We find a loophole of this scheme. Based on the intercept-resend attack, we propose a deterministic attack strategy and a probabilistic attack strategy. The malicious participant can escape the detection and obtains the secret. We also suggest two improvements to help increase the security of the original scheme.