A threshold changeable dynamic quantum secret sharing scheme with cheating identification

Quantum secret sharing holds an important place in quantum cryptography. In this paper, a threshold changeable dynamic quantum secret sharing scheme with cheating identification is firstly proposed based on the Chinese Remainder Theorem. On the premise of not altering the shared secret and the private shares of the original participants, our scheme realizes the dynamic updating of participants and for the first time achieves the changeable threshold in the quantum environment, which greatly improves the flexibility and practicality of the scheme. In addition, we generalize the entanglement swapping equations of Bell states in 2-dimension to d -dimension. During the reconstruction phase, our scheme can timely detect and identify the cheating behaviors based on the randomized components and the entanglement swapping equations of d -dimensional Bell states. Meanwhile, the randomized components ensure privacy protection for shares and avoid the interference of invalid shares when recovering the secret. Security analysis shows that our scheme is resistant to not only a series of typical external attacks but also forgery, collusion, and dishonest revoked participant attacks. Compared with the existing schemes, our scheme is not only more secure and efficient but also has lower computational consumption.