量子密码是量子理论和密钥学相结合的产物,是量子保密通信的重要组成部分。量子秘密共 享(Quantum secret sharing, QSS) 是量子密码的核心内容之一,它可以在不完全信任的通信双方间传递密钥,引起了国内外研究人员的高度关注。提出了一种基于诱骗态的BB84协议的量子秘密共享方案。Alice先产生一系列的弱相干脉冲串,并对该脉冲串进行偏振调制,然后通过分束 器分成两束,再分别对这两束脉冲通过诱骗态调制器进行强度调制后,分别发送给Bob和Charlie; Bob和Charlie 分别对发送过的脉冲进行测量并公 布结果,随后三方通过经典信道进行对基,通过协商和私密放大获得最终的安全的密钥。方案减少了量子比特产生器和测量器的数量,降低了 量子通信的费用,为量子秘密共享实用化提供了一种可参考的方法。

Quantum cryptography is the product of the combination of quantum theory and key science, and it is an important part of quantum secure communication. Quantum secret sharing (QSS) is one of the core contents of quantum cryptography. It can transfer keys between two parties that are not fully trusted. At present, it has attracted the attention of researchers at home and abroad. A novel BB84 protocol-based quantum secret sharing with decoy states is proposed. A series of weak coherent pulses generated by Alice are polarizedly modulated, then separated as two series of weak coherent pulses by a beam splitter. The two series of weak coherent pulses are intensity modulated further by a decoy modulator, and then sent to Bob and Charlie. Bob and Charlie measure the weak coherent pulses and announce the results. Based on the results, Alice, Bob and Charlie can obtain the secure key after basis reconciliation, error correction and privacy amplification. As the numbers of qubit generating and measuring devices are reduced greatly, the scheme provides a practical way for QSS technique with less cost.