Quantum Information and Computation
Security of quantum secret sharing with two-particle entanglement against individual attacks
S.-J. Qin, Fei Gao, Qiaoyan Wen, F.-C. Zhu
Abstract
Security is the most important criterion to evaluate cryptography protocols. We investigate the security of one important quantum secret sharing protocol (KKI protocol). By discriminating two mixed states, we derive the optimal relationship between the induced error rate (QBER) and the maximal amount of information gained by a dishonest participant. For a specific amount of eavesdropper's knowledge on the shared secret that we consider, the disturbance on the quantum state in terms of QBER is actually larger for the hybrid protocol than the KKI protocol. Therefore, the hybrid protocol appears to be better able to detect eavesdroppers than the KKI protocol. For this reason, we do not see any reason to employ the KKI protocol against individual attacks.