An efficient quantum secret sharing using secure direct communication

Inspired by quantum secure direct communication, a three-party quantum secret sharing approach is proposed. In the preparation phase, the sender shares a GHZ state among users. After she ensures about the security of the channel, she generates an auxiliary GHZ state and keeps it. Then she encodes three-bit information on the GHZ states, by applying the appropriate gates on her qubits. In the decoding phase, the three parties measure their qubits. The receivers achieve no information on the encoded message individually and just when they know the others´ measurement results have access to the secret message. The security of the preparation phase against various attacks is investigated. Since no qubits carrying the message are transmitted, the protocol is completely secure, if the perfect quantum channel is used. The proposed approach has a better efficiency as compared to the previous ones.