Secret sharing without monitoring signal disturbance

Abstract

Secret sharing, in which a dealer wants to split a secret in such a way that any unauthorized subset of parties is unable to reconstruct it, plays a key role in cryptography. The security of quantum protocols for the task is guaranteed by the fact that Eve's any strategies to obtain secret information from encoded quantum states should cause a disturbance in the signal. Here, we propose a quantum secret sharing (classical information) scheme for $N$ parties based on totally different principle in which monitoring signal disturbance is no longer need. In this scheme, the secret is divided among several partners by sequential transmissions of a $L$-dimensional qudit state, which can be practically implemented using a conventional laser and some standard off-the-shelf components. Our scheme paves a novel and practical way for quantum secret sharing.