Recently, Gao et al.'s [Commun. Theor. Phys. 52 (2009) 421] multiparty quantum secret sharing (MQSS) protocol with two-photon three-dimensional Bell states was enhanced by Hwang et al. [Commun. Theor. Phys. 56 (20...Recently, Gao et al.'s [Commun. Theor. Phys. 52 (2009) 421] multiparty quantum secret sharing (MQSS) protocol with two-photon three-dimensional Bell states was enhanced by Hwang et al. [Commun. Theor. Phys. 56 (2011) 79]. The improved protocol removes some unnecessary unitary operations, devices, and transmissions by the technique of decoy single photons and careful modification. However, in this paper, we investigate the security of the improved protocol and find it is insecure. The eavesdropper can steal all Alice's secret information. Furthermore, a feasible modification to remedy the security loophole is put forward. Our improved protocol provides a basic method to modify a kind of MQSS protocols which cannot resist the collusion attack.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos. 61003287, 61170272the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No. 20100005120002+1 种基金the Fok Ying Tong Education Foundation under Grant No. 131067the Fundamental Research Funds for the Central Universities under Grant No. BUPT2012RC0221
文摘Recently, Gao et al.'s [Commun. Theor. Phys. 52 (2009) 421] multiparty quantum secret sharing (MQSS) protocol with two-photon three-dimensional Bell states was enhanced by Hwang et al. [Commun. Theor. Phys. 56 (2011) 79]. The improved protocol removes some unnecessary unitary operations, devices, and transmissions by the technique of decoy single photons and careful modification. However, in this paper, we investigate the security of the improved protocol and find it is insecure. The eavesdropper can steal all Alice's secret information. Furthermore, a feasible modification to remedy the security loophole is put forward. Our improved protocol provides a basic method to modify a kind of MQSS protocols which cannot resist the collusion attack.