Physica Scripta
Cryptanalysis of quantum secret sharing based on GHZ states
Xiao-Fen Liu, Ri-Jing Pan
Abstract
In a recent paper (Hwang et al 2011 Phys. Scr. 83 045004), a subtle quantum secret sharing (QSS) protocol was proposed. One major advantage of this protocol is its high efficiency; that is, it is more efficient than other QSS protocols using the Greenberger–Horne–Zeilinger states. However, we analyzed the security of this protocol and found that it is insecure for one agent who may deduce half of the information about the deal's secret directly just by his/her piece of secret. Finally, a feasible improvement of this QSS protocol is put forward.