Participant attack on the deterministic measurement-device-independent quantum secret sharing protocol

In a recent article [Gao et al., Sci. China-Phys. Mech. Astron. 63, 120311 (2020)], a two-receiver measurement-device-independent quantum secret sharing (MDI-QSS) protocol was presented. It was proven to be secure against eavesdropping and generalized to the multireceiver case. However, the participant attack is a fatal threat to QSS protocols. Here, we highlight that a dishonest participant can obtain a sender’s secret message alone without introducing any detectable error, evidencing the vulnerability of the MDI-QSS protocol to the participant attack.