The Cryptanalysis of Yuan et al.'s Multiparty Quantum Secret Sharing Protocol

Recently, Yuan et al. summarized some previous analysis of quantum secret sharing task and designed a multiparty quantum secret sharing protocol based on the continuous variable operations (CVO) with the ideas of dense coding and ping-pong technique (YMQSS). However, our research shows that the YMQSS protocol is unable to complete the quantum secret sharing task securely if the particular participant, Bob(0), is dishonest. In order to show that, we describe the following two attack strategies: one is that Bob(0) can get the accurate shared secrets himself and leave the other sharers get his forged ones; the other one is that Bob(0) can conspire with another sharer Bob (i) (i not equal 0) to get Alice's secrets without anyone's help. Finally, our discussions and conclusions are proposed.