Four-directional controlled quantum teleportation by using a nine-qubit entangled state as the quantum channel

In this paper, we propose a four-directional controlled quantum teleportation (CQT) by using a nine-qubit entangled state as the quantum channel. In 2020, a scheme for four-directional controlled quantum teleportation by using a 10-qubit state as the quantum resource had been proposed in X. W. Zha and K. Li [Mod. Phys. Lett. B 34, 2050412 (2020)] in which the controller has no control over the two teleportation processes. In this study, it is also shown that two receivers cannot reconstruct the original state sent from the respective senders and hence the teleportation processes cannot be completed in the previous scheme. However, these problems have been resolved in our proposed scheme in which the controller has control over all the teleportation processes and none of the receivers can reconstruct the original state sent from the respective senders without the permission of the controller. Thus, our proposed scheme reduces the consumption of quantum resource and is more secure and successful as compared to the previous scheme.