The characteristics of W state are introduced.The coefficients of W state used for quantum key distribution and secret sharing are proved to be uniform in symmetrical form.The corresponding quantum key distribution scheme via W state is proposed.To insure the security of the proposed quantum key distribution protocol, the receiver switches randomly the message mode to control mode asymmetrically.The security of the protocol is discussed.Quantum secret sharing scheme is accordingly proposed.And the security of the schemes is also discussed.Compared with the quantum key distribution and secret sharing schemes with Greenberger-Horne-Zeilinger(GHZ) states,the efficiency of the proposed schemes is low. The purpose of this paper is just to prove that some states except for GHZ states can be used for quantum key distribution and secret sharing.
Verifiable secret sharing schemes are important in cloud computing environments. Thus a key can be distributed over many servers by threshold secret sharing mechanism. The key is then reconstructed when needed. Secret sharing has also been suggested for sensor networks where the links are liable to be tapped by sending the data in shares which makes the task of the eavesdropper harder. The security in such environments can be made greater by continuous changing of the way the shares are constructed. In the present paper we proposed a verifiable quantum -threshold secret sharing scheme using Lagrange interpolation and two qudit Bell state in -dimensional Hilbert space. As discussed in the second last section of this paper, the proposed scheme is enough secure against the fraud in secret share distribution phase as well as secret reconstruction phase.
The security of communication depends on the security of key,the manage of key is important for the distribution of communication,Secret sharing is a protocol to accomplish the storage of the key distribution.In this paper,the secret sharing with a two mode entanglement and single mode squeezing is discussed.It is shown that the secret sharing via three mode entanglement can be replaced by this scheme with two mode entanglement.The information can be shared in two outputs via sending two copies of the information from measurement collapse in input station to the output station.