Quantum direct secret sharing using Bell state

Abstract

In this paper, we propose an efficient multiparty quantum direct secret sharing scheme based on Bell state and Bell measurements. In our scheme, the secret information can be directly encoded into the second particles of Bell states through the local unitary operations. In order to increase the number of participants, we use the controlled-NOT gate to produce the final multipartite entangled states. In the reconstruction phase, each participant performs Bell measurements for their particles and obtains the final key strings. Furthermore, they cooperate to recover the secret information. In addition, we give a concrete example with four participants to demonstrate more clearly the integrity of our scheme. Finally, we demonstrate that our protocol can resist both collusion attack and intercept-and-resend attack.