Quantum secret sharing without entanglement

Ben Fortescue, Gilad Gour

Zhu Zhen-chao

Quantum secret sharing（QSS） which is based on the laws of quantum mechanics,instead of mathematical assumptions can share the information unconditionally securely, according to the form of sharing information, quantum secret sharing can be divided into QSS of classical messages and QSS of quantum information,QSS of classical messages can be divided into QSS of classical messages based on entanglement and QSS of classical messages without entanglement, the representative protocols in three main branches of the quantum secret sharing schemes and its latest development were introduced, also prospect analysis of the schemes’ future development was given.

Chen‐Ming Bai, Sujuan Zhang, Lu Liu

Yaoyao Zhou, Juan Yu, Zhihui Yan +4 more

Secret sharing is a conventional technique for realizing secure communications in information networks, where a dealer distributes to n players a secret, which can only be decoded through the cooperation of k (n/2<k≤n) players. In recent years, quantum resources have been employed to enhance security of secret sharing, which has been named quantum secret sharing (QSS). A multipartite bound entanglement (BE) state of an optical field, due to its special entanglement features, can be used in quantum networks to improve security and flexibility of communication. We design and experimentally demonstrate a QSS protocol, where the dealer modulates a secret on a four-partite BE state and then distributes the submodes of the BE state to four spatially separated players. The presented QSS scheme has the capability to protect secrets from eavesdropping and dishonest players, because a nonlocal and deterministic BE state is shared among four authorized players.

Ken Sasaki, Atsushi Waseda, Masakazu Soshi +1 more

FANG Yutong, Yaoyao Zhou, WANG Yukun

Quantum secret sharing （QSS） is one of the important branches of quantum cryptography， which is used to share a secret among multiple participants， and has great potential for applications in fields such as quantum computing and quantum communication. With the rapid development of quantum information， people have higher requirements for the number of users and security of quantum secret sharing. This article analyzes the entanglement characteristics of three entangled states， namely the continuous variable four component Bound Entanglement （BE） state， GHZ （Greenberger-Horn-Zeilinger） state， and Cluster state， and uses them as quantum resources to construct a four component quantum secret sharing scheme. The dependence of quantum secret sharing security on different physical parameters is theoretically calculated for each scheme. The results show that the secret key rate of different entangled state optical fields has a consistent relationship with the signal strength when four users cooperate. While the secret key rate in the BE entangled-state light field corresponding to the QSS scheme is balanced in orthogonal amplitude and orthogonal bit-phase components with a symmetric relationship when three users cooperate， the GHZ entangled-state and the Cluseter entangled-state light field corresponding to the QSS scheme show a larger secret key rate in a single orthogonal component.