A ( t , n )-threshold dynamic quantum secret sharing scheme based on two-particle quantum states

Abstract Quantum secret sharing is an important branch of quantum cryptography. In this paper, we propose a ( t , n )-threshold dynamic quantum secret sharing scheme based on two-particle quantum states. By combining Shamir’s polynomial structure with sequential quantum operations, any t authorized participants can jointly reconstruct the shared secret, while fewer than t participants cannot obtain useful information. In the recovery phase, the weighted shares of the authorized participants are successively encoded into a transmitted two-particle quantum state, and random numbers are introduced to protect the intermediate quantum information. Moreover, the proposed scheme supports participant addition and deletion without changing the original secret. A new participant can obtain a valid share with the cooperation of an authorized subset, whereas the old shares of deleted participants are invalidated by refreshing the sharing polynomial. The correctness analysis shows that the secret can be accurately recovered by an authorized subset. The security analysis addresses selected attacks under the stated assumptions, but does not establish integrity protection against active state modification. Therefore, the proposed scheme achieves flexible threshold reconstruction and dynamic participant management based on two-particle quantum states.