Encrypted broadcast quantum teleportation

In this study, we propose an encrypted quantum teleportation broadcast scheme using a 6-qubit entangled channel and an encrypted quantum teleportation scheme with a controller via a 7-qubit entangled channel. The quantum state of Alice, to be transmitted, is first encrypted into two distinct states that satisfy certain conditions. As the main sender, Alice designates two agents to transmit encrypted states to two receivers. She shares a 6-qubit entangled state with each party and provides the receivers with a 1-bit classical information containing the chosen encryption. After the agents perform measurements on the corresponding orthogonal bases and send the results to the receivers, each receiver can reconstruct the original state sent by Alice. To enhance security for the receivers, the scheme introduces Alice as a controller. The receivers can reconstruct the original state only if Alice performs a measurement and shares her measurement outcome. The use of encryption ensures that even if an agent’s qubit is intercepted, the actual state remains secure. Alice, as the controller, can also terminate the transmission if a security threat is detected or she change her mind to finish the transmission. The teleportation performance depends on how the qubit is encrypted. For a specific input state used as an example, the protocol obtained a teleportation success probability of 0.9608.