Drawing idea from the quantum secure direct communication (QSDC) and the dense coding

we propose a novel quantum secret sharing (QSS) scheme with high efficiency based on the GHZ states.Alice shares her secret message with Bob and Charlie directly using quantum correlations and a public string K

rather than shares a joint key with them and uses the joint key to transmit her message.In our scheme

a GHZ state can be used to share two bits message.We analyze the security of our scheme in the realistic and lossy channel respectively

and show it is necessary to use a public K due to the difference between quantum direct secret sharing and QSDC.