Quantum secret-sharing protocol based on Grover's algorithm

A marked state can be found with certainty in the two-qubit case of Grover's algorithm. This property is included in the proposed quantum secret-sharing protocol. In the proposed scheme, the sender prepares some initial state in private and then performs a phase shift of the marked state as the sender's bit. Then, the sender sends these two qubits to each of the two receivers. Only when the sender broadcasts the initially prepared state and then the receivers perform the corresponding inversion operation about the average, is the sender's bit faithfully revealed. Moreover, the sender can detect deception using cheat-detecting states. The proposed quantum secret-sharing protocol is shown to be secure.